JP7664155B2 - Optical computing device and method for manufacturing the same - Google Patents

Description

The present invention relates to an optical computing device that has multiple units including optical diffraction elements.

Patent Document 1 discloses a technique in which multiple optical elements, such as lenses and filters, are stacked on the optical path of signal light, and these optical elements act on the signal light in sequence. One example of an optical element is an optical diffraction element that includes multiple microcells arranged in a matrix, with the thickness or refractive index set independently of each other. These optical diffraction elements are provided on the main surface of a transparent substrate that is translucent to the signal light. An example of a material that is translucent to the signal light is quartz glass.

In an optical computing device that sequentially applies optical diffraction elements to signal light, it is important to adjust the position and direction of each optical diffraction element relative to the signal light to a predetermined position and direction. This is because if the position and direction of the optical diffraction element relative to the signal light deviates from the predetermined position and direction, it becomes difficult to exert the intended effect on the signal light.

International Publication No. 2013/027340

The manufacturing method of the optical computing device includes a process for adjusting the position and orientation of each optical diffraction element. In this process, the transparent substrate must be handled, and this handling can sometimes cause damage to the transparent substrate.

One aspect of the present invention has been made in consideration of the above-mentioned problems, and its purpose is to reduce the possibility of the transparent substrate being damaged when the optical diffraction element is aligned on the optical path of the signal light.

In order to solve the above problem, the optical diffraction element according to the first aspect of the present invention has n units U1 to Un (n is any natural number equal to or greater than 2).

In this optical diffraction element, each unit Ui (i is a natural number from 1 to n) includes a transparent substrate, a plurality of optical diffraction elements formed on one main surface of the transparent substrate, and a tray thicker than the transparent substrate, with a recess formed on one main surface and an opening formed in the recess, and the optical diffraction element is arranged so as to overlap the opening via the transparent substrate, and units U1 to Un are stacked such that any one of the optical diffraction elements included in unit Uj (j is a natural number from 1 to n-1) overlaps any one of the optical diffraction elements included in unit Uj+1, which is one layer above, in a plan view.

According to the above configuration, by handling the tray, an optical diffraction element selected from a plurality of optical diffraction elements can be arranged on the optical path of the signal light. In other words, there is no need to handle the transparent substrate in order to arrange the selected optical diffraction element on the optical path of the signal light. This reduces the possibility of the transparent substrate being damaged when arranging the optical diffraction element on the optical path of the signal light.

In addition, in the optical computing device according to the second aspect of the present invention, in addition to the configuration of the optical computing device according to the first aspect described above, the transparent substrate is made of glass and the tray is made of metal.

The above configuration can further reduce the possibility of the transparent substrate being damaged when the optical diffraction element is aligned on the optical path of the signal light.

In addition, in the optical computing device according to the third aspect of the present invention, in addition to the configuration of the optical computing device according to the first or second aspect described above, the stacked n units U1 to Un include units U1' to Un' (n' is a natural number between 2 and n) stacked in succession, and in each unit Ui' (i' is a natural number between 1 and n'), the plurality of optical diffraction elements are arranged in a matrix of N rows and M columns (N is any natural number between 1 and M), and the tray of unit U1' has a plurality of optical diffraction elements each having a major axis aligned with the major axis of the plurality of optical diffraction elements. At least one long hole is formed parallel to the column direction, and the tray of each unit Uk' (k' is a natural number between 2' and n') has a plurality of long holes whose major axes are parallel to the column direction of the optical diffraction elements, and the pitch in the row direction between adjacent long holes is equal to the pitch in the row direction of each optical diffraction element included in the optical diffraction elements, and units U1' to Un' are stacked so that parts of the long holes formed in the tray of each unit Ui' overlap.

According to the above configuration, the optical diffraction element to be used for optical axis adjustment in each unit Ui can be selected in either the row direction or the column direction, so when multiple optical diffraction elements are arranged in a matrix of N rows and M columns, any optical diffraction element can be selected and the optical axis can be adjusted.

In addition, in the optical arithmetic device according to the fourth aspect of the present invention, in addition to the configuration of the optical arithmetic device according to the first or second aspect described above, the stacked n units U1 to Un include units U1' to Un' (n' is a natural number between 2 and n) stacked in succession, and in each unit Ui' (i' is a natural number between 1 and n'), the multiple optical diffraction elements are arranged in a matrix of N rows and 1 column (N is any natural number between 2 and n'), at least one hole is formed in the tray of unit U1', and in the tray of each unit Uk' (k' is a natural number between 2 and n'), multiple holes are formed with a pitch in the row direction equal to the pitch in the row direction of each optical diffraction element included in the multiple optical diffraction elements, and the units U1' to Un' are stacked so that at least a portion of the holes formed in the tray of each unit Ui' overlap with each other.

According to the above configuration, the optical diffraction element to be used for optical axis adjustment in each unit Ui can be selected in the row direction, so when multiple optical diffraction elements are arranged in a matrix of N rows and 1 column, an arbitrary optical diffraction element can be selected in each unit Ui to adjust the optical axis.

In addition, in the optical computing device according to the fifth aspect of the present invention, in addition to the configuration of the optical computing device according to any one of the first to fourth aspects described above, a configuration is adopted in which the main surface opposite to the one main surface of the transparent substrate is in close contact with the one main surface of the tray via a liquid in the recess.

The above configuration allows the transparent substrate to be easily fixed to the tray.

In addition, in the optical computing device according to the sixth aspect of the present invention, in addition to the configuration of the optical computing device according to any one of the first to fifth aspects described above, the tray is configured to be conductive.

The above configuration reduces the risk of the optical diffraction element being damaged by static electricity.

In addition, in the optical computing device according to the seventh aspect of the present invention, in addition to the configuration of the optical computing device according to any one of the first to sixth aspects described above, the tray is configured to be magnetic.

The above configuration allows units U1' to Un' to be integrated together using magnetic force.

In addition, in the optical computing device according to the eighth aspect of the present invention, in addition to the configuration of the optical computing device according to any one of the first to seventh aspects described above, a configuration is adopted in which a recess or hole is formed on the outer periphery of the tray.

With the above configuration, the optical axis of the optical diffraction element can be easily adjusted by fitting the recess or hole with a pin provided at the tip of the manipulator.

In addition, in the optical computing device according to the ninth aspect of the present invention, in addition to the configuration of the optical computing device according to any one of the first to eighth aspects described above, the optical diffraction element is configured with a plurality of microcells whose thicknesses or refractive indices are set independently of each other.

One example of an optical diffraction element is a plurality of microcells configured in this way.

In order to solve the above problems, a manufacturing method for an optical computing device according to a tenth aspect of the present invention is a manufacturing method for an optical computing device comprising n units U1 to Un (n is any natural number equal to or greater than 2), and each unit Ui (i is a natural number equal to or greater than 1 and equal to or less than n) including a transparent substrate, a plurality of optical diffraction elements formed on one main surface of the transparent substrate, and a tray thicker than the transparent substrate, the tray having a recess formed on one main surface and an opening formed in the recess, and the optical diffraction elements are arranged to overlap the opening via the transparent substrate. In a device manufactured by this manufacturing method, the n stacked units U1 to Un include units U1' to Un' (n' is a natural number equal to or greater than 2 and equal to or less than n) that are stacked in succession. In each unit Ui' (i' is a natural number greater than or equal to 1 and less than or equal to n'), the multiple optical diffraction elements are arranged in a matrix of N rows and M columns (N is any natural number greater than or equal to 1, and M is any natural number greater than or equal to 2), and the tray of unit U1' is formed with at least one long hole whose long axis is parallel to the column direction of the multiple optical diffraction elements, and the tray of each unit Uk' (k' is a natural number greater than or equal to 2' and less than or equal to n') is formed with a multiple number of long holes whose long axes are parallel to the column direction of the multiple optical diffraction elements, and the pitch between adjacent long axes in the row direction is equal to the pitch in the row direction of each optical diffraction element included in the multiple optical diffraction elements. This manufacturing method includes a first installation step of placing unit U1' on one of the main surfaces of a unit having a guide pin protruding from the one main surface so that the guide pin fits into the long hole of unit U1'; a second installation step of placing units U2' to Un' on a layer one level above unit Uj' (j' is a natural number from 1 to n'-1) so that unit Uj'+1 is positioned so that the guide pin fits into one of the multiple long holes of unit Uj'+1; and an adjustment step of adjusting the optical axis of an optical diffraction element selected from the multiple optical diffraction elements included in unit Ui' by adjusting the position of the tray included in unit Ui' (i is a natural number from 1 to n).

According to the above configuration, the optical diffraction element to be used for optical axis adjustment in each unit Ui can be selected in either the row direction or the column direction, so when multiple optical diffraction elements are arranged in a matrix of N rows and M columns, any optical diffraction element can be selected and the optical axis can be adjusted.

In addition, the method for manufacturing an optical arithmetic device according to the eleventh aspect of the present invention includes, in addition to the configuration of the method for manufacturing an optical arithmetic device according to the tenth aspect described above, an adsorption step performed after the adjustment step, in which the optical diffraction element fixes the unit Ui' whose optical axis has been adjusted by sucking it. This manufacturing method employs a configuration in which, starting from i'=1, the adjustment step and the adsorption step are repeatedly performed as long as i'≦n'.

According to the above configuration, by repeatedly performing the adjustment process and the adsorption process starting from i'=1 as long as i'≦n', the units Ui' whose tray positions have been adjusted can be fixed sequentially using negative pressure. Therefore, when adjusting the position of the tray contained in unit Ui'+1 after unit Ui', for example, it is possible to prevent unit Ui' from moving together with unit Ui'+1. As a result, the units U1'-Un' whose tray positions have been adjusted in each unit Ui' can be integrated by negative pressure.

According to one aspect of the present invention, it is possible to reduce the possibility of the transparent substrate being damaged when arranging the optical diffraction element on the optical path of the signal light.

1 is an exploded perspective view of an optical processing device according to a first embodiment of the present invention; FIG. 2 is a partial perspective cross-sectional view of the optical computing device shown in FIG. 1 . FIG. 2 is a cross-sectional view of the optical computing device shown in FIG. 2 is a perspective view of an example of an optical diffraction element provided in each unit of the optical computing device shown in FIG. 1 . 2 is a flowchart of a method for manufacturing the optical computing device shown in FIG. 1 . (a) is a plan view of the top surface of a unit U3 included in an optical computing device according to a second embodiment of the present invention, (b) is a plan view of the top surface of a unit U2 included in the optical computing device, and (c) is a plan view of the top surface of a unit U1 included in the optical computing device.

First Embodiment
(Basic configuration of the optical computing device)
The basic configuration of an optical processing device 1 according to a first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is an exploded perspective view of the optical processing device 1. Figure 2 is a partial perspective cross-sectional view of the optical processing device 1. Note that the cross section shown in Figure 2 is the α cross section (see Figure 1) of units U1 to U3, which will be described later.

The optical computing device 1 comprises n units U1 to Un, where n is a natural number equal to or greater than 2. The unit Ui comprises a transparent substrate 11, an optical diffraction element 12, and a tray 13. Here, i is a natural number equal to or greater than 1 and equal to or less than n. In the illustrated example, n is 3, and i is 1, 2, and 3.

The transparent substrate 11 is a plate-like member made of a transparent material. In this embodiment, a plate-like member made of glass (more specifically, quartz glass) is used as the transparent substrate 11. A plurality of optical diffraction elements 12 are formed on the upper surface ("one main surface" in the claims) of the transparent substrate 11. In this embodiment, three optical diffraction elements 12 are formed. However, the number of optical diffraction elements 12 is not limited as long as there is more than one, and can be determined appropriately. Note that in Figures 1 and 2, the plurality of optical diffraction elements 12 are illustrated together. In addition, spacers 12a are formed around the plurality of optical diffraction elements 12. The structure of each optical diffraction element 12 will be described later with reference to a different drawing.

The tray 13 is a plate-like member thicker than the transparent substrate 11. In this embodiment, a plate-like member made of metal (more specifically, SUS430) is used as the tray 13. In this embodiment, a rectangular shape is adopted as the shape of the main part of the tray 13 (the part of the tray 13 that does not include the convex part 13e described later) when viewed in plan. A recess 13a is formed on the upper surface of the tray 13 (the "one main surface" in the claims) that is recessed in the thickness direction of the tray 13, and an opening 13b is formed in the recess 13a, penetrating the tray 13 in the thickness direction. The length and width of the recess 13a are longer than the length and width of the transparent substrate 11, and the length and width of the opening 13b are longer than the length and width of the optical diffraction element 12. The transparent substrate 11 described above is arranged in the recess 13a so that the optical diffraction element 12 overlaps with the opening 13b via the transparent substrate 11.

It is preferable that the lower surface of the transparent substrate 11 and the upper surface of the tray 13 (the bottom surface of the recess 13a) are in close contact with each other via a liquid. This makes it easier to fix the transparent substrate 11 to the tray 13 than using an adhesive. The liquid to be placed between the lower surface of the transparent substrate 11 and the upper surface of the tray 13 is, for example, water containing glycerin. Glycerin is less likely to volatilize than water, and does not volatilize at room temperature. This makes it possible to keep the transparent substrate 11 in close contact with the tray 13 for a longer period of time than when only water is used as the liquid.

It is preferable that the bottom surface of the recess 13a is formed with fine irregularities. The lower surface of the transparent substrate 11 is mirror-finished. By forming fine irregularities on the bottom surface of the recess 13a, the liquid dripped into the gap between the transparent substrate 11 and the recess 13a fills the gap by capillary action. At this time, the liquid diffuses into the gap while pushing out the air that was present in the gap, so that the transparent substrate 11 can be more firmly attached to the tray 13. In addition, by forming fine irregularities on the bottom surface of the recess 13a, the air that was present in the gap can be eliminated, so that the possibility of air bubbles being generated in the gap can be reduced, and thus the variation in thickness that may occur in the recess 13a and the transparent substrate 11 in the closely attached state can be suppressed.

The tray 13 is preferably made of a material having magnetism. This is because it makes it possible to integrate the units U1 to Un by magnetic force. An example of a material having magnetism is a ferromagnetic material, and a specific example of a ferromagnetic material is martensitic stainless steel. The tray 13 is preferably made of a material having electrical conductivity. This is because it makes it possible to reduce the risk of the optical diffraction elements 12 included in the units U1 to Un being damaged by static electricity.

The units U1 to Un are stacked such that one of the optical diffraction elements 12 included in unit Uj (j is a natural number between 1 and n-1) overlaps one of the optical diffraction elements 12 included in unit Uj+1, the next higher layer, in a planar view. In this embodiment, a planar view means that the transparent substrate 11 of each unit Ui is viewed from the normal direction of the main surface of the transparent substrate 11 (the upper or lower direction of the paper in the state shown in FIG. 1).

In addition, a convex portion 13e protruding in a direction perpendicular to the stacking direction is formed on the outer periphery of the main part of the tray 13, and a hole 13e1 is formed in the convex portion 13e. This hole 13e1 is a hole that fits with a pin provided at the tip of the manipulator when adjusting the optical axis of the optical diffraction element 12. By providing such a hole 13e1 on the outer periphery of the tray 13, the optical axis adjustment of the optical diffraction element 12 becomes easy. The position of the convex portion 13e on the tray 13 included in each unit Ui is provided at a position that does not overlap when the optical calculation device 1 is viewed from above. Therefore, for example, the manipulator can access the tray 13 included in any unit Ui. Note that the same effect can be obtained by providing a recess that fits with a pin provided at the tip of the manipulator instead of the hole 13e1.

In addition, a pair of holes 13f are formed in the frame of the tray 13, which is interposed between the outer periphery and the recess 13a, and penetrates from the top to the bottom of the tray 13. The number of holes 13f formed in each tray 13 may be one, but it is preferable that there are multiple holes. In this embodiment, a pair of holes 13f, i.e., two holes 13f, are used. By forming multiple holes 13f in each tray 13, it is possible to prevent each tray 13 from rotating even when the guide pin 21c described below is cylindrical.

In this embodiment, the outer periphery and the recess 13a of the tray 13 are both rectangular. Therefore, the outer periphery and the inner periphery of the above-mentioned frame are rectangular. Each of the pair of holes 13f is formed on a pair of short sides of the frame (the short side on the positive x-axis side and the short side on the negative x-axis side in FIG. 6). However, the positions of the pair of holes 13f (i.e., the positions of the guide pins 21c described later) on the tray 13 are not limited to this and can be appropriately determined within a range that does not overlap with the through holes 13ci and the group of fine holes 13di in the frame.

The pair of holes 13f are provided at positions corresponding to a pair of guide pins 21c provided on the tray 21 of the mask unit Um described later. Each of the pair of holes 13f of each unit Ui fits into each of the pair of guide pins 21c when each unit Ui is stacked on the tray 21 described later. By stacking each unit Ui using the pair of guide pins 21c and the pair of holes 13f in each unit Ui, it is possible to roughly adjust the optical axis of the optical diffraction element 12 included in each unit Ui. Therefore, when adjusting the optical axis of the optical diffraction element 12, the process of performing coarse adjustment can be omitted, making the optical axis adjustment easier.

The radius of hole 13f is designed to be slightly larger than the radius of guide pin 21c. The difference between the radius of hole 13f and the radius of guide pin 21c creates a play between hole 13f and guide pin 21c. This play functions as an adjustment allowance for the optical axis adjustment of the optical diffraction element 12 in each unit Ui. This play can be appropriately determined according to the adjustment allowance for the optical axis adjustment of the optical diffraction element 12.

The units U1 to Un are stacked in the order of unit U1, unit U2, ..., unit Un, so that the optical diffraction element 12 included in unit Uj is positioned within the opening 13b formed in the tray 13 included in unit Uj+1, the next layer above. Here, j is a natural number between 1 and n-1. Hereinafter, unit U1 is also referred to as the "lowest layer unit." Unit Un is also referred to as the "uppermost layer unit."

If the thickness of the tray 13 outside the recess 13a is t1 and the thickness of the transparent substrate 11 is s, then s<t1 holds, as described above. If the thickness of the tray 13 inside the recess 13a is t2 and the thickness of the transparent substrate 11 is s, then s=t1-t2 holds. This means that the upper surface of the transparent substrate 11 and the upper surface of the tray 13 are flush with each other. If the height of the spacer 12a is h, then h=t2 holds. This means that the units U1 to Un are stacked such that (1) the upper surface of the tray 13 included in unit Uj contacts the lower surface of the tray 13 included in unit Uj+1 in the next higher layer, and (2) the upper surface of the spacer 12a included in unit Uj contacts the lower surface of the transparent substrate 11 included in unit Uj+1 in the next higher layer. In this embodiment, t1 = 45 μm, t2 = 15 μm, s = 30 μm, and h = 15 μm (only the spacer 12a in the top unit Un has h = 50 μm).

According to the above configuration, the optical diffraction element 12 can be aligned on the optical path of the signal light by handling the tray 13. In other words, there is no need to handle the transparent substrate 11 in order to align the optical diffraction element 12 on the optical path of the signal light. This reduces the possibility that the transparent substrate 11 will be damaged when aligning the optical diffraction element 12 on the optical path of the signal light.

(Additional Configuration 1 of Optical Computing Device 1)
Additional configurations of the optical processing device 1 will be described with continued reference to FIG.

The optical calculation device 1 includes a mask unit Um and a diffusion unit Ud.

The mask unit Um has a tray 21 and a mask plate 22. The tray 21 is a plate-like member made of metal. A recess 21a is formed on the top surface of the tray 21, recessed in the thickness direction of the tray 21, and an opening 21b is formed within the recess 21a, penetrating the tray 21 in the thickness direction. The mask plate 22 is a transparent substrate that has the function of masking part of the signal light. The mask plate 22 is fitted into the recess 21a formed in the tray 21.

Guide pins 21c are formed on the frame interposed between the outer periphery of the tray 21 and the recess 21a, protruding upward in the stacking direction from the top surface of the tray 21. The number of guide pins 21c is not limited, but it is preferable that there is more than one, and in this embodiment, there are two. These guide pins 21c are provided at positions corresponding to the above-mentioned holes 13f. In this embodiment, the guide pins 21c are cylindrical in shape. However, the guide pins 21c may be cylindrical, and the shape of the bottom surface is not limited to a circular shape.

The length of the portion of the guide pin 21c that protrudes from the top surface of the tray 21 is preferably greater than (n-1) x t1 and less than or equal to n x t1. This allows the hole 13f of the unit Un located in the top layer to fit into the guide pin 21c, while preventing the guide pin 21c from interfering with the diffusion unit Ud.

As mentioned above, the radius of the guide pin 21c is designed to be slightly smaller than the radius of the hole 13f. The radius of the guide pin 21c can be determined appropriately depending on the width of the frame body of the tray 21 and the strength required of the guide pin 21c.

In this embodiment, the thickness of the tray 21 outside the recess 21a is 1800 μm, and the thickness of the tray 21 inside the recess 21a is 600 μm. The thickness of the mask plate 22 is 1200 μm.

The mask unit Um has a group of holes 13dm that communicates with the groups of holes 13d1 and 13d2 formed in the tray 13. The groups of holes 13d1 and 13d2 will be described later. The group of holes 13dm is configured in the same manner as the groups of holes 13d1 and 13d2.

The mask unit Um also has a through hole 13cm formed therein, which is in communication with the through holes 13c1 and 13c2 formed in the tray 13. The through holes 13c1 and 13c2 will be described later. The through hole 13cm is configured in the same manner as the through holes 13c1 and 13c2.

The diffusion unit Ud has a tray 31, a diffusion plate 32, and an electromagnet 33. The tray 31 is a plate-like member made of metal. A recess 31a is formed on the upper surface of the tray 31, recessed in the thickness direction of the tray 31, and an opening 31b is formed in the recess 31a, penetrating the tray 31 in the thickness direction. The diffusion plate 32 is a transparent or semi-transparent substrate that has the function of diffusing signal light. The diffusion plate 32 is fitted into the recess 31a formed in the tray 31. An electromagnet 33 is provided on the upper surface of the tray 31. If the tray 13 of the units U1 to Un, the tray 21 of the mask unit Um, and the tray 31 of the diffusion unit Ud are made of a material having magnetism, these trays can be integrated by the magnetic force generated by the electromagnet 33.

In this embodiment, the thickness of the tray 31 outside the recess 31a is 2050 μm, and the thickness of the tray 31 inside the recess 31a is 50 μm. The thickness of the diffusion plate 32 is 2100 μm. Therefore, the diffusion plate 32 protrudes 100 μm from the top surface of the tray 31. However, the size of each part of the diffusion unit Ud is not limited to this and can be selected as appropriate.

(Additional Configuration 2 of the Optical Computing Device)
The additional configuration of the optical processing device 1 will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view of the optical processing device 1. Note that the cross-section shown in Fig. 3 is the β cross-section of the optical processing device 1 (see Fig. 1).

When n is any natural number equal to or greater than 3, the tray 13 included in each unit Uk other than units Un and Un-1 has a through hole 13ck that terminates on the underside of the tray 13 included in unit Uk+1 in the next layer above, and through holes 13ck+1 and 13ck+2 that communicate with the through holes 13ck+1 and 13ck+2 formed in the tray 13 included in unit Uk+1 in the next layer above. Here, k is a natural number between 1 and n-2. Also, the tray 13 included in unit Un-1 has a through hole 13cn-1 that terminates on the underside of the tray 13 included in unit Un in the next layer above.

According to the above configuration, units U1 to Un can be integrated by negative pressure by applying suction from the underside of through holes 13c1 and 13c2 formed in the tray 13 included in unit U1. In the illustrated example, units U1 and U2 can be integrated by negative pressure by applying suction from the underside of through hole 13c1 formed in the tray 13 included in unit U1. Also, units U2 and U3 can be integrated by negative pressure by applying suction from the underside of through hole 13c2 formed in the tray 13 included in unit U1.

When n is an arbitrary natural number of 3 or more, the tray 13 included in each unit Uk other than units Un and Un-1 has a group of holes 13dk that communicates with the group of holes 13dk+1 formed in the tray 13 included in unit Uk+1 of the next upper layer. Here, k is a natural number of 1 to n-2. Also, the tray 13 included in unit Un-1 has a group of holes 13dn-1 that terminates at the bottom surface of the tray 13 included in unit Un of the next upper layer. In 1 shown in FIG. 3, the groups of holes 13d1 and 13d2 are smaller in diameter than the through holes 13c1 and 13c2 described above and consist of a plurality of holes that penetrate each tray 13. The groups of holes 13d1 and 13d2 configured in this manner have both the function of reducing the pressure of the gas and the function of reducing the effective area of the opening, compared to the through holes 13c1 and 13c2 with a large diameter, and are therefore suitable for weakening the adsorption force. Therefore, in a state where the units U1 to Un are weakly integrated using the pore groups 13d1 and 13d2, each unit Ui can be translated in a direction perpendicular to the stacking direction. That is, in a state where the units U1 to Un are weakly integrated using the pore groups 13d1 and 13d2, the optical axis adjustment of the optical diffraction element 12 included in the units U1 to Un can be performed. In addition, since the portion of the region where the pore groups 13d1 and 13d2 are formed that does not have pores supports the region of the unit Un that terminates the pore groups 13d1 and 13d2, it is possible to prevent the region of the unit Un that terminates the pore groups from being deformed by negative pressure. In this embodiment, a structure called a punching metal or punching mesh is used as the pore groups 13d1 and 13d2. Note that each of the multiple pores constituting the pore groups 13d1 and 13d2 may be provided periodically or randomly. In addition, the diameter of each pore can be appropriately determined according to the pressure of the desired gas. The shape of each pore can also be determined appropriately. If the pores are arranged periodically, the periodic structure and the pitch of the periodic structure can also be determined appropriately.

According to the above configuration, the units U1 to Un can be integrated by applying negative pressure by applying suction from the underside of the group of holes 13d1 formed in the tray 13 included in the unit U1. In the illustrated example, the units U1 to U3 can be integrated by applying negative pressure by applying suction from the underside of the group of holes 13d1 formed in the tray 13 included in the unit U1.

The optical arithmetic device 1 shown in Figures 1 to 3 employs n=3, and is configured so that all of the units U1 to U3 can be integrated by negative pressure. In other words, the optical arithmetic device 1 shown in Figure 3 employs n=n'=3 as n and n', and the tray included in unit Uk' (k' is a natural number between 1 and n'-2) has a through hole terminated by the main surface opposite to the one main surface of the tray included in unit Uk'+1 and a through hole communicating with the through hole formed in the tray included in unit Uk'+1, and the tray included in unit Un'-1 has a through hole terminated by the main surface opposite to the one main surface of the tray included in unit Un', which is an example of an optical arithmetic device. The optical computing device 1 shown in FIG. 3 is an example of an optical computing device in which the tray included in unit Uk' has a group of pores formed therein that communicate with the group of pores formed in the tray included in unit Uk'+1, and the tray included in unit Un'-1 has a group of pores formed therein that terminate at the main surface opposite to the one main surface of the tray included in unit Un'.

However, in one aspect of the present invention, in addition to the configuration of the optical computing device 1 shown in FIG. 2, (1) one or more units (e.g., units configured similarly to unit U3) stacked on the one main surface side (upper side in the state shown in FIG. 2) of the tray included in unit U3 may be further provided, (2) one or more units (e.g., units configured similarly to unit U3) stacked on the main surface side opposite to the one main surface of the tray included in unit U1 (lower side in the state shown in FIG. 2), or (3) one or more units stacked on the upper side of unit U3 and one or more units stacked on the lower side of unit U1 may be further provided. In this case, only units U1'-Un' out of units U1-Un can be integrated by negative pressure. Units U1'-Un' can be fixed by a fixing means such as an adhesive in a state integrated by a magnetic force generated by electromagnet 33 after being integrated by negative pressure, as will be described later with reference to FIG. 5. Then, by stacking one or more units different from units U1'-Un' on at least one of the upper and lower sides of units U1'-Un', an optical computing device 1 in which n exceeds n' is obtained. Note that the process of fixing units U1'-Un' using a fixing means such as an adhesive can also be performed in a state where they are integrated by negative pressure. In this case, the process of integrating them by magnetic force can be omitted.

When an adhesive is used as the above-mentioned fixing means, it is preferable that the adhesive is one that allows the timing of starting the curing reaction to be selected arbitrarily. Examples of such adhesives include an adhesive using an ultraviolet curing resin and an adhesive using a thermosetting resin. In this embodiment, an ultraviolet curing resin is used. In these adhesives, the resin curing reaction is started by irradiating ultraviolet rays or heating. Therefore, when stacking each unit Ui, an appropriate amount of adhesive is applied to the opening 13b located between the adjacent unit Uj' (j' is a natural number between 1 and n'-1) and unit Uj'+1, and the optical axis of the optical diffraction element 12 is adjusted while the adhesive is in an uncured state, and then the adhesive can be cured at an arbitrary timing. Note that the units integrated using the adhesive are not limited to units U1' to Un', and may be all units U1 to Un, or all units U1 to Un and the diffusion unit Ud.

The multiple units stacked on at least one of the upper and lower sides of units U1 to U3 may be units that can be integrated by negative pressure, like units U1 to U3. In other words, the scope of the present invention also includes an optical arithmetic device obtained by stacking multiple optical arithmetic devices 1 as shown in FIG. 2. Here, each optical arithmetic device 1 may be fixed using a fixing means such as an adhesive. An optical arithmetic device 1 in which n exceeds n' can also be obtained in this way.

The adhesive force between the units when the units U1 to Un are integrated using the hole groups 13d1 to 13d2 is weaker than the adhesive force between the units when the units U1 to Un are integrated using the through holes 13c1 to 13c2. Therefore, with the units U1 to Un integrated using the hole groups 13d1 to 13d2, each unit Ui can be translated in a direction perpendicular to the stacking direction. In other words, with the units U1 to Un integrated using the hole groups 13d1 to 13d2, the optical axis of the optical diffraction element 12 included in the units U1 to Un can be adjusted.

When n is 2 or more and the n stacked units U1 to Un include consecutively stacked units U1' and U2', the tray 13 included in unit U1' has a through hole 13c1 that terminates at the bottom surface of the tray 13 included in unit U2', which is one level above.

According to the above configuration, by applying suction from the underside of the through hole 13c1 formed in the tray 13 included in unit U1', units U1 and U2 can be integrated by negative pressure.

In addition, when n is 2 or more and the n stacked units U1 to Un include consecutively stacked units U1' and U2', the tray 13 included in unit U1' has a group of pores 13d2 formed therein that terminates at the bottom surface of the tray 13 included in unit U2', which is one layer above.

According to the above configuration, by applying suction from the underside of the group of holes 13d1 formed in the tray 13 included in unit U1', units U1' and U2' can be integrated by negative pressure.

As described above, the units U1' and U2' can be fixed in an integrated state using a fixing means such as an adhesive. At least one of the upper and lower sides of the integrated units U1' and U2' may be stacked with one or more units different from the units U1' and U2', or with an optical computing device 1 manufactured separately.

(Structure of Optical Diffraction Element)
The structure of the optical diffraction element 12 will be described with reference to Fig. 4. Fig. 4 is a perspective view of an example of one of the optical diffraction elements 12 included in each unit Ui of the optical computing device 1.

As shown in FIG. 4, the optical diffraction element 12 is a planar optical diffraction element and is composed of a number of microcells, each of which has a thickness or refractive index set individually and independently of each other. In this embodiment, the thickness of each microcell is set individually and independently of each other.

Here, a microcell refers to a cell with a cell size of less than 10 μm, for example. Also, the cell size refers to the square root of the area of the cell. For example, if the shape of the microcell in plan view is a square, the cell size is the length of one side of the cell. The lower limit of the cell size is not particularly limited, but is, for example, 1 nm. Also, the thickness of the optical diffraction element 12 (i.e., the maximum thickness among the thicknesses of each microcell) is not particularly limited, but is typically several μm.

The above-mentioned multiple microcells are formed within the effective area of the transparent substrate 11. In this embodiment, the effective area of the transparent substrate 11 is a square with sides of 150 μm, and is composed of 200 × 200 microcells arranged in a matrix. Each microcell is composed of a pillar having a base of 750 nm on a 100 μm thick base (not shown in FIG. 4). The size of one side of each microcell (750 nm in this embodiment) is preferably approximately half the wavelength of the signal light (1550 nm in this embodiment). The height of each pillar is, for example, 0 nm, 100 nm, 200 nm, ..., 1100 nm, 1200 nm (13 steps of 100 nm), and the refractive index of the microcell composed of the pillar is determined to be the desired refractive index.

In this embodiment, the size of the pillars in the optical diffraction element 12 is 750 nm, but is not limited to this. In other words, the size of the pillars in the optical diffraction element 12 may be less than 10 μm. In addition, the number of cells and the effective area size of the optical diffraction element 12 are also arbitrary.

(Tray manufacturing method)
The following describes a method for manufacturing the above-mentioned tray 13. In this embodiment, the tray 13 is manufactured using a film forming process and an etching process.

In the film formation process, a metal film made of SUS430 and having a thickness of 45 μm is formed in the shape of a tray 13 with an opening 13b on a substrate using an electric field nickel plating method, which is an example of an electric field plating method. The shape of the tray 13 with the opening 13b can be realized by providing a mask on the substrate.

The etching process is a process of etching the area corresponding to the recess 13a using a method called wet etching or chemical etching. In this embodiment, the area corresponding to the recess 13a is etched over a depth of 30 μm.

By combining the film formation process and the etching process, it is possible to easily manufacture a tray 13 having the desired shape.

However, the method of manufacturing the tray 13 is not limited to this. For example, the tray 13 can be manufactured using only electrolytic nickel plating, which is an example of electrolytic plating, by using two types of mask patterns. The tray 13 can also be manufactured by separately manufacturing a portion with a thickness of t2 (the portion surrounding the opening 13b) and a portion with a thickness of s (the portion surrounding the recess 13a) and then bonding the two portions. Methods for bonding the two portions include diffusion bonding and adhesion.

It is preferable that one of the upper and lower surfaces of the tray 13 included in each unit Ui is finished smoothly, and the other has fine irregularities. If both the upper and lower surfaces of the tray 13 are finished smoothly, the upper surface of the unit Ui-1 located below and the lower surface of the unit Ui located above may adhere to or bond with each other. In this case, it becomes difficult or impossible to adjust the position of unit Ui relative to unit Ui-1. By finishing one of the upper and lower surfaces of the tray 13 smoothly and forming fine irregularities on the other, it is possible to achieve precision in the thickness direction while preventing sticking that may occur between the upper surface of the unit Ui-1 located below and the lower surface of the unit Ui located above.

(Method of manufacturing optical computing device)
A manufacturing method M1 of the optical computing device 1 will be described with reference to Fig. 5. Fig. 5 is a flowchart of the manufacturing method M1 of the optical computing device 1. Note that in this embodiment, the description will be given on the assumption that each transparent substrate 11 has already been manufactured with the optical diffraction element 12 and the spacer 12a formed on the main surface thereof.

As shown in FIG. 5, manufacturing method M1 includes a sealing process S11, an installation process S12, a weak adhesion process S13, an adjustment process S14, a strong adhesion process S15, a magnetization and fixing process S16, a removal process S17, and a hardening process S18.

The sealing process S11 is a process for manufacturing a unit Un (in this embodiment, n is 3) by dripping liquid into the gap between the transparent substrate 11 and the recess 13a to bring the lower surface of the transparent substrate 11 into close contact with the upper surface of the tray 13 (the bottom surface of the recess 13a). In this embodiment, the unit Ui (in this embodiment, i is 1, 2, 3) shown in FIG. 1 is manufactured. In this embodiment, water containing glycerin is used as the liquid used in the sealing process S11. However, the liquid is not limited to this and may be water or glycerin.

The installation process S12 is a process of placing units U1 to U3 and diffusion unit Ud on mask unit Um in the order shown in FIG. 1. In the installation process S12, when unit Uj+1 is placed on the layer one level above unit Uj (j is a natural number between 1 and n-1), guide pin 21c is fitted into hole 13f of unit Uj+1. Also, in the installation process S12, when unit Uj+1 is placed on the layer one level above unit Uj, an appropriate amount of adhesive (in this embodiment, ultraviolet curing resin) is applied to the area near the outer edge of opening 13b. Also, when diffusion unit Ud is placed on the layer one level above unit Uj, an appropriate amount of adhesive (in this embodiment, ultraviolet curing resin) is applied to the upper surface of unit Uj. It is preferable to determine the amount of adhesive and the area to which it is applied so that after unit Uj+1 is placed on the layer one level above unit Uj, it comes into contact with unit Uj and unit Uj+1 in the area near the outer edge of opening 13b, but does not come into contact with spacer 12a located in the center of opening 13b.

The weak suction step S13 is a step of suctioning the underside of the group of holes 13dm formed in the mask unit Um. The group of holes 13dm is suctioned using a vacuum pump or a decompression pump. By carrying out the weak suction step S13, the group of holes 13d1 formed in the tray 13 of unit U1 and the group of holes 13d2 formed in the tray 13 of unit U2 are suctioned, so that each unit Ui is weakly fixed on the mask unit Um. In the manufacturing method M1, the weak suction step S13 is continued until the removal step S17 is carried out.

In manufacturing method M1, starting from i=1, adjustment step S14 and strong adsorption step S15 are repeatedly performed for each unit Ui as long as i≦3.

The adjustment process S14 is a process of adjusting the optical axis of the optical diffraction element 12 by adjusting the position and orientation of the tray 13 using a manipulator. In this embodiment, signal light is irradiated from below the mask unit Um so as to penetrate the opening 21b, and the signal light projected onto the diffusion plate 32 is monitored using a camera installed above the diffusion unit Ud. In the adjustment process S14, the optical axis of the optical diffraction element 12 is adjusted according to the pattern of the signal light projected onto the diffusion plate 32. By performing the adjustment process S14, one of the optical diffraction elements 12 included in the unit (e.g., unit Uj+1) for which the optical axis adjustment is performed overlaps with one of the optical diffraction elements 12 included in the unit one level below (e.g., unit Uj) in a planar view.

The strong suction step S15 is a step of strongly fixing a desired unit Ui to the mask unit Um or unit Ui-1 located below it by sucking from the underside of the through-hole 13cm formed in the mask unit Um. In the strong suction step S15, the unit Ui to be fixed can be selected by selecting any one of the through-holes 13cm formed in the mask unit Um. The suction of the hole group 13dm is performed using a vacuum pump or a vacuum generator. In the manufacturing method M1, the strong suction step S15 performed for each unit Ui is continued until the removal step S17 is performed. In other words, in the manufacturing method M1, the unit Ui that has been strongly fixed once continues to be strongly fixed until the removal step S17 is performed.

The magnetization and fixing process S16 is a process in which the electromagnet 33 of the diffusion unit Ud is turned on to magnetize the tray 13 of each unit Ui and integrate all units U1 to U3.

The removal process S17 is a process for stopping suction of the through holes 13cm and the group of holes 13dm formed in the mask unit Um. By carrying out the removal process S17, the units U1 to U3 can be removed from the mask unit Um. The electromagnet 33 that was turned on in the magnetization and fixing process S16 continues to be on. Therefore, the optical axis of the optical diffraction element 12 of each unit Ui can be kept in the state adjusted in the adjustment process S14.

The curing step S18 is a step of curing the ultraviolet curable resin that constitutes the adhesive by irradiating ultraviolet light to all of the units U1 to U3 and the diffusion unit Ud that have been integrated by the magnetic force of the electromagnet 33 after the removal step S17 has been performed. By performing the curing step S18, it is possible to integrate all of the units U1 to U3 and the diffusion unit Ud with the cured adhesive. Therefore, all of the units U1 to U3 and the diffusion unit Ud remain integrated even when the electromagnet 33 is turned off.

The adjustment process S14, strong adhesion process S15, magnetization and fixing process S16, removal process S17, and hardening process S18 included in manufacturing method M1 can also be used when stacking and integrating another unit with the units U1 to U3 integrated in the above-mentioned hardening process S18.

As described above, by carrying out manufacturing method M1, an optical computing device 1 in which the optical axis of the optical diffraction element 12 of each unit Ui is adjusted can be obtained.

Second Embodiment
The configuration of an optical arithmetic device 1A according to a second embodiment of the present invention will be described with reference to Fig. 6. Fig. 6(a) is a plan view of the upper surface of a unit U3A included in the optical arithmetic device 1A, (b) is a plan view of the upper surface of a unit U2A included in the optical arithmetic device 1A, and (c) is a plan view of the upper surface of a unit U1A included in the optical arithmetic device 1A.

The optical arithmetic device 1A is based on the optical arithmetic device 1 according to the first embodiment (see Figures 1 to 3), and can be considered a modified version of the optical arithmetic device 1. In this embodiment, only the configuration of the optical arithmetic device 1A that is different from the optical arithmetic device 1 will be described, and a description of the configuration that is the same as the optical arithmetic device 1 will be omitted.

The optical computing device 1A includes n units U1A to UnA. The unit UiA includes a transparent substrate 11, a plurality of (six in this embodiment) optical diffraction elements ₁₂₁₁ , _{1212, 1213 , 1221} , ₁₂₂₂ , and ₁₂₂₃ , and a tray 13. Here, i is a natural number between 1 and n. In the illustrated example, n is 3, and i is 1, 2, and 3.

The unit UiA is different from the unit Ui included in the optical computing device 1 in that it includes a plurality of optical diffraction elements ₁₂₁₁ , ₁₂₁₂ , ₁₂₁₃ , ₁₂₂₁ , ₁₂₂₂ , and ₁₂₂₃ , that a long hole 13fA is formed in the tray 13 of each unit UiA instead of a hole 13f, and that the area and pattern in which the through holes 13c1 and 13c2 are formed and the area and pattern in which the hole groups 13d1 and 13d2 are formed are different. In this embodiment, the optical diffraction elements ₁₂₁₁ , ₁₂₁₂ , _{1213, 1221 , 1222} , and ₁₂₂₃ , the long hole 13fA, the guide pin 21c associated with the long hole 13fA, the through holes 13c1 and 13c2, and the hole groups 13d1 and 13d2 will be described.

(Optical Diffraction Element)
The optical diffraction elements 12 ₁₁ , 12 ₁₂ , 12 ₁₃ , 12 ₂₁ , 12 ₂₂ , and 12 ₂₃ are formed on the upper surface of the transparent substrate 11 ("one of the principal surfaces" in the claims) in the same manner as the optical diffraction element 12 in the optical computing device 1. As shown in (a) to (c) of FIG. 6, the optical diffraction elements 12 _IJ are arranged in a matrix of N rows and M columns. Here, N is any natural number equal to or greater than 1, M is any natural number equal to or greater than 2, I is a natural number equal to or greater than 1 and equal to or less than N, and J is a natural number equal to or greater than 1 and equal to or less than M. In the illustrated example, N is 2, M is 3, I is 1, 2, and J is 1, 2, and 3. In addition, each optical diffraction element 12 _IJ is configured in the same manner as the optical diffraction element 12 shown in FIG. 4. However, in each optical diffraction element 12 _IJ , the thickness or refractive index distribution in a plurality of microcells is set individually. In addition, in (a) to (c) of Figures 6, the solid lines of the squares surrounding each optical diffraction element _12IJ typically indicate the spacers 12a (see Figure 2). In (a) to (c) of Figures 6, the reference numerals for the spacers 12a are omitted.

In the following, in a matrix with N rows and M columns, the direction in which the column number changes within the same row (the x-axis direction in (a) to (c) of Figure 6) is referred to as the column direction. Also, in a matrix with N rows and M columns, the direction in which the row number changes within the same column (the y-axis direction in (a) to (c) of Figure 6) is referred to as the row direction.

In this embodiment, the pitch in the column direction and the pitch in the row direction of each optical diffraction element _12IJ are both 5.5 mm. However, the pitch in the column direction and the pitch in the row direction of each optical diffraction element _12IJ are not limited to this and can be appropriately determined. In addition, the pitch in the column direction and the pitch in the row direction of each optical diffraction element _12IJ may be different. Note that the pitch in the column direction of each optical diffraction element _12IJ means the center-to-center distance between adjacent optical diffraction elements in the column direction, and the pitch in the row direction of each optical diffraction element _12IJ means the center-to-center distance between adjacent optical diffraction elements in the column direction.

(Guide pin)
6, the guide pins 21c provided on the mask unit UmA of the optical processing device 1A are configured to have a smaller radius than the guide pins 21c (see FIG. 1) provided on the mask unit UmA of the optical processing device 1. This is because, as the optical diffraction elements _12IJ are arranged in a matrix, when an optical diffraction element _12IJ to be used for optical axis adjustment is selected within the same row, the tray 13 can be moved along the column direction.

By making the radius of the guide pin 21c smaller than the radius of the guide pin 21c in the optical computing device 1, the amount of movement of the tray 13 within the range of the width of a pair of short sides constituting the frame of the tray 13, that is, the amount of movement along the column direction, can be increased. Note that, as will be described in detail later, the shape of the long hole 13fA formed in the frame of the tray 13 in the optical computing device 1A is not circular but a rounded oval, which is a configuration for increasing the amount of movement of the tray 13 along the column direction.

(long hole)
In the tray 13 included in each unit UiA, a pair of long holes 13fA are formed in the frame interposed between the outer periphery and the recess 13a, penetrating from the upper surface to the lower surface of the tray 13. However, the long holes 13fA formed in the tray 13 of the unit U1A are different in form from the long holes 13fA formed in the units U2A to UnA (units U2A and U3A in this embodiment). The shapes and arrangements of these long holes 13fA are described below.

A pair of oblong holes 13fA formed in the tray 13 of the unit U1A corresponds to a pair of holes 13f formed in the tray 13 of each unit UiA of the optical computing device 1 shown in FIG. 1. The opening shape of the pair of holes 13f is circular. In contrast, the opening shape of the pair of oblong holes 13fA is a rounded oval. A rounded oval is a figure composed of a rectangle and two semicircles. Here, the diameters of the two semicircles are both set to be equal to the pair of short sides constituting the rectangle. The rounded oval is obtained by joining the chords of the semicircles to each of the pair of short sides constituting the rectangle. In the following, a line segment that passes through the center of each of the two semicircles and has both ends intersecting with the arcs of the two semicircles is referred to as the long axis. In addition, a line segment that passes through the midpoint of the long axis and has both ends intersecting with each of the pair of long sides of the rectangle and is perpendicular to the long axis is referred to as the short axis. The length of the major axis is equal to the sum of the length of the long side of the rectangle and the diameter of the semicircle, and the length of the minor axis is equal to the length of the short side of the rectangle.

Each of the pair of long holes 13fA is formed so that its long axis is parallel to the column direction of the matrix of N rows and M columns. However, the shape of the opening of the long hole 13fA may be any shape that has a long axis and a short axis. Examples of shapes of the opening other than a rounded oval include a rectangle and an ellipse.

Each pair of slots 13fA formed in units U2A and U3A is composed of three slots 13f1 to 13f3. The number of slots 13f1 to 13f3 constituting the pair of slots 13fA is expressed as 2N-1, where N is the number of rows of the optical diffraction elements.

The pair of elongated holes 13f1 are formed in the same manner as the elongated holes 13fA in the unit U1A. When the unit U2A is placed on the upper layer of the unit U1A so that the elongated holes 13f1 are fitted to the guide pins 21c, any one of the optical diffraction elements _121J arranged in the first row of the unit U2A can be overlapped with any one of the optical diffraction elements _121J arranged in the first row of the unit U1A. In this case, any one of the optical diffraction elements _122J arranged in the second row of the unit U2A can be overlapped with any one of the optical diffraction elements _122J arranged in the second row of the unit U1A. The unit U3A is similar to the unit U2A.

The pair of long holes 13f2, 13f3, like the pair of long holes 13f1, are formed so that their long axes are parallel to the column direction of the matrix of N rows and M columns. The pair of long holes 13f2, 13f3 are formed so as to sandwich the pair of long holes 13f1 in the row direction. In the state shown in FIG. 6, the pair of long holes 13f2 are formed above the pair of long holes 13f1 (positive y-axis direction), and the pair of long holes 13f3 are formed below the pair of long holes 13f1 (negative y-axis direction).

In each pair of slots 13f1 to 13f3, the pitch between adjacent long axes in the row direction is configured to be equal to the pitch of each optical diffraction element _12IJ in the row direction. In this embodiment, the pitch between adjacent slots in the row direction is 5.5 mm. However, the pitch between adjacent long axes in the row direction is not limited to this and can be appropriately determined according to the pitch of each optical diffraction element _12IJ in the row direction. The pitch between adjacent slots in the row direction means the distance between the long axes of two slots adjacent to each other in the row direction.

The length of the short axis of the long holes 13f1 to 13f3 is designed to be slightly longer than the diameter of the guide pin 21c. The difference between the length of the short axis and the diameter of the guide pin 21c creates a play between the long holes 13f1 to 13f3 and the guide pin 21c in the row direction. This play functions as an adjustment margin in the row direction in the optical axis adjustment of the optical diffraction element _12IJ in each unit UiA. In addition, in the long holes 13f1 to 13f3, in order to make the pitch in the row direction between adjacent long axes equal to the pitch in the row direction of each optical diffraction element _12IJ , the length of the short axis of the long holes 13f1 to 13f3 and the diameter of the guide pin 21c are set to be smaller than the pitch in the row direction of each optical diffraction element _12IJ .

When the unit U2A is placed on the upper layer of the unit U1A so that the long hole 13f2 fits into the guide pin 21c, any one of the optical diffraction elements _12-1J arranged in the first row of the unit U2A can be overlapped with any one of the optical diffraction elements _12-2J arranged in the second row of the unit U1A. When the unit U2A is placed on the upper layer of the unit U1A so that the long hole 13f3 fits into the guide pin 21c, any one of the optical diffraction elements _12-2J arranged in the second row of the unit U2A can be overlapped with any one of the optical diffraction elements _12-1J arranged in the first row of the unit U1A. The same applies to the unit U3A.

In the optical computing device 1A, when the units U2A to UnA are stacked, the long hole to be fitted onto the guide pin 21c is selected from the long holes 13f1 to 13f3, so that it is possible to select whether the optical diffraction element to be used for optical axis adjustment in each of the units U2A to UnA is the optical diffraction element _12-1J or the optical diffraction element _12-2J . In other words, it is possible to select the optical diffraction element to be used for optical axis adjustment in the row direction.

As described above, in the optical computing device 1A, a pair of elongated holes 13fA with rounded oval openings are formed in the tray 13 of each unit UiA. Therefore, the optical diffraction element used for optical axis adjustment in each unit UiA can be selected from the preselected optical diffraction element _12-1J or optical diffraction element _12-2J . In other words, the optical diffraction element used for optical axis adjustment can be selected in the row direction.

As described above, the optical diffraction element used for optical axis adjustment in each unit UiA can be selected in either the row direction or the column direction, so that an arbitrary optical diffraction element 12 _IJ can be selected in each unit UiA to adjust the optical axis. Therefore, in the optical calculation device 1A, the units U1A to UnA are stacked such that any one of the optical diffraction elements 12 _IJ included in the unit UjA (j is a natural number between 1 and n-1) overlaps any one of the optical diffraction elements 12 _IJ included in the unit Uj+1A one level above in plan view. In this embodiment, plan view means that the transparent substrate 11 of each unit UiA is viewed from the normal direction (z-axis direction in the coordinate system shown in FIG. 6) to the main surface of the transparent substrate 11.

In each of units U2A and U3A, the number of long holes 13f2 formed in the tray 13 is not limited, but preferably multiple, and in this embodiment, two. Similarly, in each of units U2A and U3A, the number of long holes 13f3 formed in the tray 13 is not limited, but preferably multiple, and in this embodiment, two. By having multiple long holes 13f2 and 13f3, as with holes 13f in the first embodiment, the process of performing coarse adjustment can be omitted when adjusting the optical axis, making the optical axis adjustment easier.

(Through hole)
As described above, in the optical computing device 1A, the optical diffraction element used for optical axis adjustment in each unit UiA can be selected in either the row direction or the column direction. Accordingly, in the optical computing device 1A, the configurations of the through hole 13c1 formed in the tray 13 of the unit U1A and the through hole 13c2 formed in the tray 13 of the unit U2A are made different from those in the optical computing device 1. The through holes 13c1 and 13c2 in the optical computing device 1A will be described below.

As shown in each of (a) to (c) of FIG. 6, the tray 13 of each unit UiA is configured to be mirror-symmetrical with respect to a line passing through the center of gravity of the tray 13 and parallel to the y-axis as the axis of symmetry, and to be mirror-symmetrical with respect to a line passing through the center of gravity of the tray 13 and parallel to the x-axis as the axis of symmetry. The center of gravity of the tray 13 coincides with the intersection of two diagonals in the rectangular main part of the tray 13. In the following, the center of gravity of the tray 13 is regarded as the origin of the xy plane, and the area where x and y are positive is referred to as the first quadrant, the area where x is negative and y is positive is referred to as the second quadrant, the area where x and y are negative is referred to as the third quadrant, and the area where x is positive and y is negative is referred to as the fourth quadrant.

Through holes 13c1 (see FIG. 6A) formed in the tray 13 of unit U1A and through holes 13c2 (see FIG. 6B) formed in the tray 13 of unit U2A are formed in sets in each of the first to fourth quadrants. In this embodiment, the through holes 13c1 and 13c2 will be described using the first quadrant as an example, and a description of the through holes 13c1 and 13c2 formed in the second to fourth quadrants will be omitted.

As shown in FIG. 6A, two rows and five columns of through holes 13c1 are formed in the first quadrant of the tray 13 of the unit U1A. In addition, two rows and five columns of through holes 13cm (not shown in FIG. 6) are formed in the mask unit Um so as to communicate with the through holes 13c1 formed in the tray 13 of the unit U1A, and further through holes 13cm are formed at a position different from the two rows and five columns of through holes 13cm, at a position terminated by the main surface of the tray 13 of the unit U1A on the negative z-axis direction side. The further through holes 13cm are used to adsorb the unit U1A. A first tube for sucking the through holes 13cm is connected to these through holes 13cm.

In this embodiment, in order to independently control the on/off of suction in the through holes 13cm in different columns among the 2 rows and 5 columns of through holes 13cm and the further through holes 13cm described above, a separate first tube is connected to the through hole 13cm for each column, and the further first tube is connected to the further through hole 13cm described above. In other words, a total of six first tubes for suctioning the inside are connected to the through holes 13cm in the first quadrant.

Similarly, a total of six first tubes are connected to each of the through holes 13cm in the second to fourth quadrants. The total of 24 first tubes connected to each of the through holes 13cm in the first to fourth quadrants are grouped into one second tube for every four tubes corresponding to the same row or further through holes 13cm. Thus, six second tubes are connected to the through holes 13cm in all quadrants. Each second tube is provided with a first valve. By individually opening and closing the first valves provided on each of the second tubes, it is possible to independently control the on/off of suction in the through holes 13cm and further through holes 13cm in different rows, and the on/off of suction in the through holes 13c1 in different rows.

As shown in FIG. 6B, two rows and one column of through holes 13c2 are formed in the first quadrant of the tray 13 of unit U2A. As such, the number of through holes 13c2 is less than the number of through holes 13c1, and therefore one of the through holes 13c1 is terminated by the main surface on the negative z-axis side of the tray 13 of unit U2A. Therefore, by sucking the through hole 13c1 that is terminated by the main surface on the negative z-axis side of the tray 13 of unit U2A, unit U2A can be adsorbed.

At least one of the through holes 13c2 in the two rows and one column communicates with one of the through holes 13c1 in the two rows and five columns, and is terminated by the main surface on the negative z-axis side of the tray 13 of unit U3A. Therefore, unit U3A can be adsorbed by sucking the through hole 13c2 that is terminated by the main surface on the negative z-axis side of the tray 13 of unit U3A.

In the optical computing device 1A configured in this manner, the through hole 13c1 of the unit U1A and the through hole 13c2 of the unit U2A are both configured with two rows of through holes, so that regardless of which of the long holes 13f1 to 13f3 is selected as the long hole to be fitted with the guide pin 21c, each unit UiA can be adsorbed in order from i=1 to i=3.

(Pores)
As described above, in the optical calculation device 1A, the optical diffraction element used for optical axis adjustment in each unit UiA can be selected in either the row direction or the column direction. Accordingly, in the optical calculation device 1A, the configurations of the hole group 13d1 formed in the tray 13 of the unit U1A and the hole group 13d2 formed in the tray 13 of the unit U2A are made different from those in the optical calculation device 1. The hole groups 13d1 and 13d2 in the optical calculation device 1A will be described below.

The group of pores 13d1 (see FIG. 6(a)) formed in the tray 13 of unit U1A and the group of pores 13d2 (see FIG. 6(b)) formed in the tray 13 of unit U2A are each formed in one set in each of the first to fourth quadrants described above, and are also formed in one set in each of the regions spanning the first and second quadrants and the regions spanning the third and fourth quadrants. Hereinafter, the pore groups 13d1 and pore groups 13d2 formed in the first to fourth quadrants, respectively, will be referred to as the first pore group 13d1 and the first pore group 13d2, and the pore groups 13d1 and pore groups 13d2 formed in the region spanning the first and second quadrants and the region spanning the third and fourth quadrants will be referred to as the second pore group 13d1 and the second pore group 13d2.

In this embodiment, the first pore groups 13d1 and 13d2 are described using the first quadrant as an example, and a description of the first pore groups 13d1 and 13d2 formed in the second to fourth quadrants is omitted. The second pore groups 13d1 and 13d2 are different from the first pore groups 13d1 and 13d2 in the position and size of the region in which they are formed. However, apart from the position and size of the region in which they are formed, the second pore groups 13d1 and 13d2 are configured in the same way as the first pore groups 13d1 and 13d2. Therefore, in this embodiment, a detailed description of the second pore groups 13d1 and 13d2 is omitted.

As shown in FIG. 6A, a first group of holes 13d1 consisting of a plurality of holes is formed in the first quadrant of the tray 13 of the unit U1A. The diameter of each of these holes is smaller than the diameter of the through holes constituting the through holes 13c1 and 13c2. This is also true for the first group of holes 13d2 described later. Therefore, the suction force when the first group of holes 13d1 and 13d2 are used is weaker than the suction force when the through holes 13c1 and 13c2 are used. Therefore, suction using the through holes 13c1 and 13c2 is also referred to as strong suction, and suction using the first group of holes 13d1 and 13d2 is also referred to as weak suction.

In addition, in the first group of holes 13d1, the multiple holes are formed in a rectangular region so as to have a planar hexagonal lattice structure. In addition, in the mask unit Um, a group of holes 13dm (not shown in FIG. 6) is formed so as to communicate with the first group of holes 13d1 formed in the tray 13 of the unit U1A. A third tube for suctioning the inside is connected to these groups of holes 13dm.

In this embodiment, the first group of holes 13d1 is divided into sub-regions of one row and five columns. In order to independently control the on/off of suction in different columns of the one row and five columns of the sub-regions, a separate third tube is connected to each sub-region for each column. In other words, a total of five third tubes for suctioning the inside are connected to the sub-regions in the first quadrant.

Similarly, a total of five third tubes are connected to each of the first pore groups 13d1 in the second to fourth quadrants. A total of 20 third tubes connected to each of the first pore groups 13d1 in the first to fourth quadrants are grouped into one fourth tube for every four tubes corresponding to the same row. Therefore, five fourth tubes are connected to the first pore groups 13d1 in all quadrants. A second valve is provided on each fourth tube. By individually opening and closing the second valves provided on each fourth tube, it is possible to independently control the on/off of suction in sub-regions of different rows of the first pore group 13d1.

As shown in FIG. 6B, a first pore group 13d2 consisting of a plurality of pores is formed in the first quadrant of the tray 13 of the unit U2A. Each of these pores is smaller in diameter than the through holes constituting the through holes 13c1 and 13c2. In the first pore group 13d2, the plurality of pores are formed in a rectangular region so as to have a planar hexagonal lattice structure. The rectangular region in which the first pore group 13d2 is formed is configured to have a shorter length along the y-axis direction than the rectangular region in which the first pore group 13d1 is formed. In this way, since the rectangular region in which the first pore group 13d2 is formed is narrower than the rectangular region in which the first pore group 13d1 is formed, one of the first pore groups 13d1 is terminated by the main surface on the negative z-axis side of the tray 13 of the unit U2A. Therefore, unit U2A can be adsorbed by sucking the first group of holes 13d1 that terminates on the main surface of the tray 13 of unit U2A on the negative z-axis side.

At least one of the first pore groups 13d2 communicates with one of the first pore groups 13d1 and terminates at the main surface on the negative z-axis side of the tray 13 of unit U3A. Therefore, unit U3A can be adsorbed by sucking the first pore group 13d2 that terminates at the main surface on the negative z-axis side of the tray 13 of unit U3A.

In the optical computing device 1A configured in this manner, regardless of which of the long holes 13f1 to 13f3 is selected as the long hole to be fitted onto the guide pin 21c, each unit UiA from i=1 to i=3 can be adsorbed together.

(Modification)
The optical calculation device 1A shown in Fig. 6 employs n = 3, and is configured so that all of the units U1A to U3A can be integrated by negative pressure. However, in one aspect of the present invention, in addition to the units U1A to U3A shown in Fig. 6, (1) one or more units (e.g., a unit configured similarly to the unit U3A) stacked on the one main surface side (upper side in the state shown in Fig. 6) of the tray included in the unit U3A may be further provided, (2) one or more units (e.g., a unit configured similarly to the unit U3A) stacked on the main surface side (lower side in the state shown in Fig. 2) opposite to the one main surface of the tray included in the unit U1A may be further provided, or (3) one or more units stacked on the upper side of the unit U3A and one or more units stacked on the lower side of the unit U1A may be further provided. In this case, the total number n of units included in the optical arithmetic device 1A becomes greater than 3, and the units that can be integrated by negative pressure are only units U1'A to Un'A (n'=3 in this case) among units U1A to UnA. In this respect, the optical arithmetic device 1A is similar to the optical arithmetic device 1.

In addition, in this embodiment, a matrix arrangement of N rows and M _columns (N is any natural number equal to or greater than 1, and M is any natural number equal to or greater than 2) is adopted as the arrangement of the multiple optical diffraction elements 12IJ. However, the arrangement of the multiple optical diffraction elements _12IJ is not limited to this, and may be a matrix arrangement of N rows and 1 column (N is any natural number equal to or greater than 1). In this case, it is not necessary to move the tray 13 along the column direction to select the optical diffraction element to be used for optical axis adjustment in each unit UiA. Therefore, when an arrangement of N rows and 1 column is adopted, it is preferable to adopt a through hole whose opening shape is circular instead of the long hole 13fA shown in FIG. 6C, the long holes 13f1, 13f2, and 13f3 shown in FIG. 6B, and the long holes 13f1, 13f2, and 13f3 shown in FIG. 6A.

That is, the tray 13 of unit U1A is formed with a hole (preferably a pair of holes) having a circular opening, and it is preferable that the tray 13 of each unit U1A, U2A is formed with a hole (preferably a pair of holes) whose pitch in the row direction is equal to the pitch in the row direction of each optical diffraction element _12IJ .

(Production method)
The manufacturing method of the optical calculation device 1A is obtained by modifying the installation step S12 based on the manufacturing method M1 of the optical calculation device 1 shown in Fig. 5. In this embodiment, only the installation step S12 after the modification will be described, and the descriptions of the sealing step S11, the weak suction step S13, the adjustment step S14, the strong suction step S15, the magnetization fixing step S16, and the removal step S17 will be omitted.

Due to the difference in shape between the long holes 13fA formed in the tray 13 of unit U1A and the long holes 13fA formed in the trays 13 of units U2A and U3A, the modified installation process S12 includes a first installation process and a second installation process.

The mask unit Um used in this manufacturing method has guide pins 21c, similar to the mask unit Um used in manufacturing method M1 (see FIG. 1). The guide pins 21c are provided so as to protrude from the upper surface of the mask unit Um (an example of one of the main surfaces of the unit in the claims). The first installation step is a step of placing the unit U1A on the upper surface of the mask unit Um. In the first installation step, when the unit U1A is placed on the upper surface of the mask unit Um, the guide pins 21c are fitted into the long holes 13fA of the unit U1A.

The second installation process is a process of placing units U2A to UnA so that unit Uj+1A is located one layer above unit UjA (j is a natural number between 1 and n-1). In this embodiment, the second installation process is a process of placing unit U2A one layer above unit U1A, and placing unit U3A one layer above unit U2A. In the second installation process, when unit Uj+1A is placed one layer above unit UjA, guide pin 21c is fitted into one of long holes 13f1 to 13f3 of unit Uj+1.

In this manufacturing method, when stacking units U2A to UnA, the optical diffraction element to be used for optical axis adjustment can be selected in the row direction by selecting the long hole to be fitted into guide pin 21c from among long holes 13f1 to 13f3.

In addition, in this manufacturing method, a pair of elongated holes 13fA with rounded oval openings are formed in the tray 13 of each unit UiA, making it possible to select the optical diffraction element to be used for optical axis adjustment in the column direction.

As described above, in this manufacturing method, the optical diffraction element used for optical axis adjustment in each unit UiA can be selected in either the row direction or the column direction, so that any one of the multiple optical diffraction elements 12IJ included in unit _UjA can be arbitrarily overlapped in a planar view with any one of the multiple optical diffraction elements _12IJ included in unit Uj+1A, which is one layer above.

[Additional Notes]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

1 Optical computing device 11 Transparent substrate 12 Optical diffraction element 12a Spacer 13 Tray 13a Recess 13b Opening 13cm, 13c1, 13c2 Through hole 13dm, 13d1, 13d2 Hole group

Claims (11)

The device includes n units U1 to Un (n is any natural number equal to or greater than 2),
Each unit Ui (i is a natural number of 1 to n) includes a transparent substrate, a plurality of optical diffraction elements formed on one main surface of the transparent substrate, and a tray that is thicker than the transparent substrate, the tray having a recess formed on one main surface and an opening formed in the recess, and the optical diffraction elements are arranged to overlap with the opening via the transparent substrate,
The units U1 to Un are stacked such that any one of the plurality of optical diffraction elements included in a unit Uj (j is a natural number not less than 1 and not more than n-1) overlaps any one of the plurality of optical diffraction elements included in a unit Uj+1 one level above in plan view.
An optical computing device comprising: The transparent substrate is made of glass, and the tray is made of metal.
2. The optical computing device according to claim 1 . The n stacked units U1 to Un include units U1' to Un'(n' is a natural number between 2 and n) stacked successively,
In each unit Ui′ (i′ is a natural number equal to or greater than 1 and equal to or less than n′), the plurality of optical diffraction elements are arranged in a matrix of N rows and M columns (N is an arbitrary natural number equal to or greater than 1, and M is an arbitrary natural number equal to or greater than 2),
At least one slot having a major axis parallel to the row direction of the plurality of optical diffraction elements is formed in the tray of the unit U1′,
In the tray of each unit Uk′ (k′ is a natural number equal to or greater than 2 and equal to or less than n′), a plurality of long holes are formed, each of whose long axes is parallel to the column direction of the plurality of optical diffraction elements, and the pitch between adjacent long holes in the row direction is equal to the pitch in the row direction of each optical diffraction element included in the plurality of optical diffraction elements,
The units U1' to Un' are stacked such that parts of the slots formed in the trays of the units Ui' overlap each other.
3. The optical computing device according to claim 1, wherein the optical computing device is a first optical computing device. The n stacked units U1 to Un include units U1' to Un'(n' is a natural number between 2 and n) stacked successively,
In each unit Ui′ (i′ is a natural number equal to or greater than 1 and equal to or less than n′), the plurality of optical diffraction elements are arranged in a matrix of N rows and 1 column (N is an arbitrary natural number equal to or greater than 2),
The tray of the unit U1' has at least one hole formed therein,
a tray of each unit Uk′ (k′ is a natural number not less than 2 and not more than n′) is formed with a plurality of holes whose pitch in the row direction is equal to the pitch in the row direction of each optical diffraction element included in the plurality of optical diffraction elements;
The units U1' to Un' are stacked such that at least a portion of the holes formed in the trays of the units Ui' overlap with each other.
3. The optical computing device according to claim 1, wherein the optical computing device is a first optical computing device. a main surface of the transparent substrate opposite to the one main surface is in close contact with the one main surface of the tray via a liquid in the recess;
5. The optical computing device according to claim 1, wherein the optical computing device comprises: The tray is electrically conductive.
6. The optical computing device according to claim 1, wherein the optical computing device is a first optical computing device. The tray is magnetic.
7. The optical computing device according to claim 1, wherein the optical computing device comprises: The tray has a recess or a hole formed in the outer periphery.
8. The optical computing device according to claim 1, wherein the optical computing device comprises: The optical diffraction element is composed of a plurality of microcells each having a thickness or a refractive index set independently of one another.
9. The optical computing device according to claim 1, wherein the optical computing device comprises: A method for manufacturing an optical computing device comprising n units U1 to Un (n is any natural number equal to or greater than 2), each unit Ui (i is a natural number equal to or greater than 1 and equal to or less than n) including a transparent substrate, a plurality of optical diffraction elements formed on one main surface of the transparent substrate, and a tray thicker than the transparent substrate, the tray having a recess formed on one main surface and an opening formed in the recess, the optical diffraction elements being disposed so as to overlap with the opening via the transparent substrate,
The n stacked units U1 to Un include units U1' to Un'(n' is a natural number between 2 and n) stacked successively,
In each unit Ui′ (i′ is a natural number equal to or greater than 1 and equal to or less than n′), the plurality of optical diffraction elements are arranged in a matrix of N rows and M columns (N is an arbitrary natural number equal to or greater than 1, and M is an arbitrary natural number equal to or greater than 2),
At least one slot having a major axis parallel to the row direction of the plurality of optical diffraction elements is formed in the tray of the unit U1′,
In the tray of each unit Uk′ (k′ is a natural number equal to or greater than 2′ and equal to or less than n′), a plurality of long holes are formed, each of whose long axes is parallel to the column direction of the plurality of optical diffraction elements, and the pitch between adjacent long axes in the row direction is equal to the pitch in the row direction of each optical diffraction element included in the plurality of optical diffraction elements,
a first installation step of placing a unit U1′ on one of the main surfaces of a unit having a guide pin protruding from the one main surface such that the guide pin fits into the long hole of the unit U1′;
a second installation step of placing units U2' to Un' on a layer one level above unit Uj'(j' is a natural number not less than 1 and not more than n'-1) such that unit Uj'+1 is positioned such that the guide pin fits into any one of the plurality of long holes of unit Uj'+1;
and an adjustment step of adjusting the optical axis of an optical diffraction element selected from the plurality of optical diffraction elements included in unit Ui′ by adjusting the position of the tray included in unit Ui′ (i is a natural number of 1 or more and n or less).
A method for manufacturing an optical computing device comprising the steps of: The method further includes a suction step performed after the adjustment step, in which the optical diffraction element fixes the unit Ui′ whose optical axis has been adjusted by suction,
Starting from i'=1, the adjusting step and the adsorption step are repeatedly performed as long as i'≦n'.
The method for manufacturing an optical computing device according to claim 10 .

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