JP4872065B2 - Automatic loop collection type data collection system - Google Patents

Description

  The present invention relates to an automatic loop collection type data collection system configured using an optical switch based on a new principle.

  Conventionally, when a state of a river or the like is monitored, for example, a monitor camera or a sensor is attached to a monitoring base, data is collected from the monitoring center, and the data is monitored for monitoring. In this case, the collected data is generally collected as an electrical signal and converted into an image signal or the like.

  However, in the case of bad weather such as a typhoon, there is a problem that monitoring cannot be continued if the electric wire is cut or a power failure occurs.

  On the other hand, the present inventors have a thermal lens forming optical element having a light absorbing layer having a region exhibiting light absorptivity according to a wavelength band and a region exhibiting light transmittance in Patent Document 1, and exhibits light absorptivity. A control light having a wavelength selected from a region and a signal light having a wavelength selected from a region exhibiting optical transparency are coaxially irradiated onto the light absorption layer, and a donut having a different signal light opening angle depending on whether or not the control light is irradiated We proposed an optical switch technology that changes the optical path by forming a mold output light and providing a perforated mirror.

  Recently, the present inventors have used an optical switch using this technology, and an automatic loop collection type data collection system configured by connecting a monitoring device and a data collection module arranged at each site with an optical cable. (Japanese Patent Application No. 2006-202633).

Further, Patent Document 2 proposes an optical switch that does not take electrical or mechanical means, changes the refractive index of the switch material by irradiation of a control beam, and changes the optical path of the signal beam.
JP 2002-275713 A U.S. Pat.No. 4,585,301

  However, the automatic circulation collection type data collection system proposed in Japanese Patent Application No. 2006-20063 using the technique of Patent Document 1 previously proposed by the present inventors is applicable even when the electric wire is cut or a power failure occurs. It is possible to continue monitoring, and the collection of collected data can be constructed with an inexpensive configuration without performing electrical processing. However, since it still requires many optical components, There was room for further improvement for practical use.

  On the other hand, it is conceivable to apply the optical path switching method disclosed in Patent Document 2 to this automatic orbital collection type data collection system. In this case, however, the deflection angle cannot be increased so much and the laser that changes the refractive index is used. There was a problem that light requires high power.

  The present invention has been made in view of such circumstances, and based on a novel operating principle, the number of optical components of the apparatus can be further reduced, the apparatus configuration is simpler, and the cost can be reduced. It is an object of the present invention to provide an automatic lap-collecting data collection system that can continue to be monitored even in the case of a disconnection or a power failure, and is expected to be put to practical use in earnest.

According to the present invention, in order to solve the above problems,
It consists of a monitoring device and a data collection module located at each site connected by an optical cable.
The monitoring device includes a trigger pulse generator for sending a trigger pulse for collecting data at a predetermined timing to each data collection module via an optical cable, and a collected data collection unit for receiving collected data from each data collection module via an optical cable And a control unit that transmits a control signal for data collection to each data collection module,
Each data collection module is provided with an identification code. Each data collection module includes an automatic circulation mechanism including a first optical switch and a second optical switch, and a data collection unit for collecting data at each base. A control unit connected to the data collection unit and the optical cable, and a third optical switch for controlling on / off of the connection between the control unit and the optical cable,
Each of the first optical switch and the second optical switch inputs light source light and signal light having a wavelength different from the light source light, and turns on / off the output of the light source light by turning on / off the signal light. It consists of a light control type optical switch of the control method,
When the automatic circulation mechanism receives a trigger pulse from the monitoring device, it turns on the third switch and causes the control unit to transmit the data collected by the data collection unit to the monitoring device together with the identification code to the monitoring device via the optical cable. An automatic loop-collecting data collection system that sends pulses to the next data collection module via an optical cable,
The first optical switch
A first signal input unit that inputs a first light source light that is continuous light having a first wavelength λ1 and a first signal light that is pulsed light having a second wavelength λ2.
A first thermal lens-forming optical element having a first light absorption layer having a wavelength band that absorbs the first signal light and transmits the first light source light;
The first light absorbing layer includes a first light condensing unit that condenses the first signal light and the first light source light with different condensing points in a direction perpendicular to the optical axis,
The first thermal lens forming optical element has a heat based on a refractive index distribution reversibly generated due to a temperature rise occurring in a region where the first light absorption layer absorbs the first signal light and its peripheral region. By using the lens, when the first signal light is not irradiated and a thermal lens is not formed, the first light source light is emitted as unpolarized light that does not change the traveling direction, and the first signal light is irradiated. When the thermal lens is formed, the state of emitting the first light source light as the deflected light whose traveling direction is changed is realized in correspondence with the presence or absence of the irradiation of the first signal light,
Further, of the first light source light emitted from the first thermal lens forming optical element, the non-deflected light is output from the first output port, and the deflected light is output from the second output port. With an optical path switching unit,
The second optical switch
The first light source light having the first wavelength λ1 output from the second output port of the first optical switch is taken in as the second signal light, and the second signal light and the second wavelength λ2 are continuously generated. A second signal input unit that receives a second light source light that is light;
A second thermal lens forming optical element having a second light absorption layer having a wavelength band that absorbs the second signal light and transmits the second light source light;
A second condensing part for condensing the second signal light and the second light source light on the second light absorbing layer with the condensing points different from each other in the direction perpendicular to the optical axis;
The second thermal lens forming optical element has a heat based on a refractive index distribution reversibly generated due to a temperature rise occurring in a region where the second light absorption layer absorbs the second signal light and its peripheral region. By using the lens, when the second signal light is not irradiated and the thermal lens is not formed, the second light source light is emitted as unpolarized light, and the second signal light is irradiated to form a thermal lens. If so, the state of emitting the second light source light as the deflected light is realized corresponding to the presence or absence of irradiation of the second signal light,
Further, the second thermal lens forming optical element outputs a second light source that outputs non-deflected light from the first output port and outputs deflected light from the second output port among the output second light source light. With an optical path switching unit,
The first signal input unit of the first optical switch is connected to the optical cable, takes the trigger pulse as the first signal light,
The first output port of the first optical switch is connected to the third optical switch;
A second output port of the first optical switch is connected to a second signal input of the second optical switch;
An automatic loop-collecting data collection system is provided in which the second output port of the second optical switch is connected to an optical cable.

  According to the present invention, based on a novel operating principle, the number of optical components of the device can be further reduced, the device configuration can be simplified, the cost can be reduced, the electric wire is cut, or a power failure occurs. Even in such a case, it is possible to continue monitoring, and it is possible to provide an automatic circulation collection type data collection system that is expected to be put into practical use.

  Embodiments of the present invention will be described.

  FIG. 1 is a diagram schematically showing a configuration of an automatic circulation collection type data collection system 1 according to an embodiment of the present invention.

  In this automatic circulation collection type data collection system 1, the monitoring device 2 and a plurality of data collection modules 3 installed at each site are connected cyclically via optical cables C1, C2, C3 and the like. In FIG. 1, only one data collection module 3 is shown in detail for convenience. The monitoring device 2 can be installed, for example, in a monitoring center separated from each data collection module 3. In the present embodiment, the monitoring device 2 includes an uninterruptible power supply 2A, and also includes a laser oscillation device 2B for power supply and the like, and supplies power to each data collection module 3 via an optical cable C3. Can be done. Although not shown, the monitoring device 2 includes a trigger pulse generator for sending a trigger pulse for collecting data at a predetermined timing to each data collection module 3 via the optical cable C1, and each data via the optical cable C2. A collection data collection unit that receives collection data from the collection module 3, a control unit that transmits a control signal for data collection to each data collection module 3, a monitor device for monitoring, and the like are also provided.

  Each data collection module 3 is given an identification code, and each data collection module 3 collects data at the automatic circulation mechanism 4 including the first optical switch SW1 and the second optical switch SW2 and the respective bases. A data collection unit 5, a control unit (CPU) 6 connected to the data collection unit 5 and the optical cable C2, and performing various controls for data collection, a communication control unit (Ether) 7, an electrical signal and an optical signal And an E / O unit 8 that performs mutual conversion, and a third optical switch SW3 that controls on / off of connection between the control unit 6 side and the optical cable C2 side. A photovoltaic cell 3A and a rechargeable battery 3B connected to the optical cable C3 are also provided. As the data collection unit 5, a monitor camera, various sensors, or the like can be used according to the purpose of use and application.

  As an identification code given to each data collection module, for example, a well-known “IP address” widely used for digital information transfer can be suitably used together with a data identification method using an IP address. With this identification code, it is possible to accurately grasp from which data collection module the transmitted data is transmitted.

  As will be described later, the first optical switch SW1 and the second optical switch SW2 of the automatic rotation mechanism 4 respectively input light source light and signal light having a different wavelength, and turn on / off the input of the signal light. It comprises an optical control type optical switch that controls on / off of the output of the signal light by turning off. As the third optical switch SW3, a normal on / off control type optical switch can be used.

  When the automatic circulator 4 receives the trigger pulse from the monitoring device 2 via the cable C1, the automatic circulation mechanism 4 turns on the third switch SW3, and the control unit 6 collects the data collected by the data collection unit 5 via the optical cable, for example. The time is transmitted to the monitoring device 2 and the trigger pulse is sent to the next data collection module 3 via the optical cable C1.

  Here, the optical switch used for the automatic circulation mechanism 4 of the data collection unit 3 will be described.

  FIG. 2 is a schematic configuration example of this optical switch. As schematically illustrated in FIG. 2, the optical switch SW has an input port 12 for taking in the light source light 11 that is continuous (CW) light, and a pulsed signal having a wavelength different from the wavelength of the light source light 11. An input port 14 for taking in the light [gate light] 13 is provided. A first collimating lens 15 for converting incident light source light 11 into parallel light is disposed downstream of the input port 12, and downstream of the input port 14 is used for converting incident signal light 13 into parallel light. A second collimating lens 16 is disposed. For convenience, FIG. 2 shows parallel light as a straight line having no width. A mixer 17 is disposed on the downstream side of the first collimating lens 15 and the second collimating lens 16, and the mixer 17 transmits the light source light 11 that is parallel light from the first collimating lens 15, and The signal light that is parallel light from the second collimating lens 16 is reflected and its optical path is changed. A first condenser lens 18, a thermal lens forming optical element 19, a third collimator lens 20, a wavelength selective transmission filter 21, a branch mirror 22, and a second condenser lens 23 are disposed downstream of the mixer 17. Has been. The first condenser lens 18 condenses (converges) the light source light 11 and the signal light 13 from the mixer 17 on the light absorption layer of the thermal lens forming optical element 19. Here, the light source light 11 and the signal light 13 are incident on the first condenser lens 18 at positions shifted in a direction perpendicular to the optical axis, and the light absorption layer of the thermal lens forming optical element 19 is also on the optical axis. Incident light is incident at a position shifted in a perpendicular direction, and the condensing point is separated.

  The thermal lens forming optical element 19 emits unpolarized light that does not change the traveling direction when only the light source light 11 is incident, and forms a thermal lens when the light source light 11 and the signal light 13 are incident simultaneously, The light is emitted as deflected light whose traveling direction is changed. The third collimating lens 20 makes the light source light 11 (unpolarized light and deflected light) and the signal light 13 parallel light. The wavelength selective transmission filter 21 transmits the light source light 11 and cuts the signal light 13. A branch mirror 22 provided downstream of the optical wavelength selection filter 21 branches the non-deflected light and the deflected light, and the deflected light is reflected to change its optical path. Unpolarized light travels straight. Further, a mirror 24 that further changes the optical path of the deflected light whose optical path has been changed and a third condenser lens 25 that condenses the light from the mirror 24 are disposed above the branch mirror 22 in the drawing. The switch SW has two output ports 26 and 27. The output port 26 outputs light of unpolarized light collected by the second condenser lens 23 when the signal light 13 is off. The output port 27 changes the optical path by the branch mirror 22 and the mirror 24 when the signal light 13 is turned on, and outputs the light of the deflected light condensed by the third condenser lens 25.

  In the switch SW, the wavelength of the light source light 11 is light having a wavelength that shows transparency to the light absorption layer of the thermal lens forming optical element 19. In addition, the wavelength of the signal light 13 is light having a wavelength that is absorptive with respect to the light absorption layer of the thermal lens forming optical element 19.

  The material of the light absorption layer in the thermal lens forming optical element 19, the wavelength band of the light source light 11, and the wavelength band of the signal light 13 are appropriately combined so that the operation of the optical switch SW can be performed efficiently. Can be selected and used. As a specific setting procedure, for example, first, the wavelength or wavelength band of the light source light 11 is determined, and then the optimal combination of the material of the light absorption layer and the wavelength of the signal light 3 is selected to control this. can do. Further, after determining the combination of the wavelengths of the light source light 11 and the signal light 13, a material for the light absorption layer suitable for this combination may be selected. Alternatively, after determining the material of the light absorption layer, a combination of wavelengths of the light source light 11 and the signal light 13 may be selected.

  As the first collimating lens 15, the second collimating lens 16, and the third collimating lens 20, for example, an aspherical lens having a focal length of 8 mm can be used, but the focal length does not need to be 8 mm and is smaller. It goes without saying that an even shorter focal length may be used for the optical switch SW. Further, although it is not necessary to use an aspheric lens, an aspheric lens is preferable in order to reduce the size and weight.

  As the optical mixer 17, for example, a known optical member such as a dichroic mirror that transmits the light source light 11 and reflects the signal light 13 can be used. Of course, it goes without saying that the positions of the input port 12 and the input port 14 may be switched so that the light source light 11 is reflected and the signal light 13 is transmitted.

  As the first condenser lens 18, the second condenser lens 23, and the third condenser lens 25, for example, an aspherical lens having a focal length of 8 mm can be used, but the focal length is not necessarily 8 mm. Needless to say, a shorter focal length may be used to make the optical switch SW smaller. Further, although it is not necessary to use an aspheric lens, an aspheric lens is preferable in order to reduce the size and weight.

  In the optical switch SW, the light source light 11 and the signal light 13 are condensed by the first condenser lens 18 at or near the incident surface of the light absorption layer of the thermal lens forming optical element 19 in the light traveling direction. When the light source light 11 and the signal light 13 are condensed at the same position near the incident surface of the light absorption layer of the thermal lens forming optical element 19, the light source light 1 spreads in a donut shape. This situation is shown in FIG. When the signal light 13 is not present, the light source light 11 is a round beam as shown in the photograph 1a of FIG. 3A, but when the signal light 13 is simultaneously irradiated to the same place, the photograph of FIG. It becomes donut shape like 1b. It is considered that the light-absorbing layer incident surface has a clear and large donut shape. In the optical switch SW, the incident surface of the light absorption layer is a surface corresponding to a position where the donut shape is clear and large when the light source light 11 and the signal light 13 are condensed at the same place. Of course, the light source light 11 and the signal light 13 that are actually used are separated by 25 to 50 μm in the direction perpendicular to the optical axis at the position of the condensing point, so that a donut shape is not formed, but the light source light 11 and the signal light are adjusted during adjustment. 13 is made incident on the same point to form a donut shape, and then the condensing points of the light source light 11 and the signal light 13 are separated to adjust the position. In addition, when the distance between the condensing points of the light source light 11 and the signal light 13 is less than 25 μm, the beam is not a round beam as shown in FIG. When the light source light 11 becomes a crescent-shaped beam, if it is condensed and then incident on the optical fiber, the incident efficiency is reduced, which may impair practicality. Further, when the distance exceeds 50 μm, the deflection angle tends to decrease.

  The thermal lens forming optical element 19 has a schematic configuration as shown in FIG. 4, but only the light absorbing layer is shown in FIG. 2 for ease of explanation. In FIG. 4, the light absorption layer 32 of the thermal lens forming optical element 31 (19) is used by sealing a dye in a solvent in a glass container 33. As the dye soluble in the solvent, a dye exhibiting absorptivity in the wavelength region of the signal light to be used and having no permeability in the wavelength region of the light source light to be used can be used. For example, the glass container 33 through which the laser beam 34 passes can have a glass thickness of about 500 μm, and the light absorption layer 32 can have a thickness of about 200 to 1000 μm.

  Specific examples of the dye include, for example, xanthene dyes such as rhodamine B, rhodamine 6G, eosin and phloxine B, acridine dyes such as acridine orange and acridine red, azo dyes such as ethyl red and methyl red, porphyrin dyes, Phthalocyanine dyes, cyanine dyes such as 3,3′-diethylthiacarbocyanine iodide, 3,3′-diethyloxadicarbocyanine iodide, triarylmethane dyes such as ethyl violet and Victoria Blue R, naphthoquinone A dye, an anthraquinone dye, a naphthalene tetracarboxylic acid diimide dye, a perylene tetracarboxylic acid diimide dye, or the like can be suitably used. Moreover, these pigment | dyes can be used individually or in mixture of 2 or more types.

  As the solvent, a solvent that dissolves at least the dye to be used can be used. However, the temperature (boiling point) of boiling without being thermally decomposed when the temperature rises during the formation of the thermal lens is 100 ° C. or higher, preferably 200. Those having a temperature of at least ° C, more preferably at least 300 ° C can be suitably used. Specifically, inorganic solvents such as sulfuric acid, halogenated aromatic hydrocarbons such as o-dichlorobenzene, aromatic substituted aliphatics such as 1-phenyl-1-xylylethane or 1-phenyl-1-ethylphenylethane Organic solvents such as hydrocarbons and nitrobenzene derivatives such as nitrobenzene can be suitably used.

  As the wavelength selective transmission filter 21, it is possible to use a dielectric filter or the like that shields the signal light 13 slightly transmitted through the thermal lens forming optical element 19 and transmits the light source light 11. If the signal light 13 is absorbed by the thermal lens forming optical element 19 to such an extent that there is no practical problem, the wavelength selective transmission filter 21 is not necessarily used.

  Here, the deflection of the light source light 11 by the thermal lens formation in the thermal lens forming optical element 19 will be described.

  When the signal light 13 is absorbed by the light absorption layer of the thermal lens forming optical element 19, the temperature of the light absorption layer rises and the refractive index changes. As the temperature increases, the refractive index generally changes in a decreasing direction. The intensity distribution of laser light emitted from a normal laser light source or laser light emitted from a normal laser light source and transmitted through an optical fiber is a Gaussian distribution. Further, the light obtained by condensing the laser light with a lens or the like has a Gaussian distribution. Therefore, the refractive index distribution in the light absorption layer irradiated with the signal light 13 has the lowest refractive index on the optical axis of the signal light 13, and the decrease in the refractive index around the signal light 13 is reduced. Further, since there is heat conduction, the refractive index changes even in a portion where light is not irradiated.

  FIG. 5 is a diagram illustrating a situation where the light source light 11 is deflected. In order to simplify the explanation, in FIG. 5, light refraction due to the difference in refractive index between the light absorption layer and the medium around the light absorption layer is ignored. In FIG. 5, the light absorption layer 32 of the thermal lens forming optical element 31 (19) is irradiated with only the light source light 35 (11), and the light source light 35 (11) and the signal light 36 (13) are simultaneously applied. The case of irradiation is shown. In the figure, 37 is light source light transmitted through the light absorption layer 32 of the thermal lens forming optical element 31 (19) when the signal light 36 (13) is not irradiated. Reference numeral 38 denotes light source light transmitted through the light absorption layer 32 of the thermal lens forming optical element 31 (19) when the signal light 36 (13) is irradiated. Further, the light intensity distribution 39 of the signal light in the vicinity of the incident surface of the light absorption layer 32 of the thermal lens forming optical element 31 (19) and the vicinity of the emission surface of the light absorption layer 32 of the thermal lens forming optical element 31 (19). The light intensity distribution 40 is also shown.

  FIG. 5a schematically shows an optical path of the laser beam when the laser beam is not condensed, and FIG. 5b schematically shows an optical path of the laser beam when the laser beam is condensed. The intensity distribution regions 39 and 40 of the laser light when the laser light is not condensed do not change between the vicinity of the entrance surface and the exit surface of the light absorption layer 32. This means that the light source light 35 (11) passes through the region where the refractive index changes little as it travels through the light absorption layer 32. On the other hand, when the laser beam is collected, the intensity distribution regions 39 and 40 of the laser beam are greatly changed near the entrance surface and the exit surface of the light absorption layer 32, and the region is expanded near the exit surface. This means that the refractive index also gradually increases, and the action of receiving a larger deflection as the light source light 35 (11) advances through the light absorption layer 32 is exerted. Since the refractive index change changes substantially in proportion to the signal light power, the refractive index change decreases as the light absorption layer 32 is advanced.

  In FIG. 5b, the light source light 35 (11) is also condensed on the incident surface of the light absorption layer 32 of the thermal lens forming optical element 31 (19), but it may be near the incident surface. In particular, the light source light 35 (11) may be condensed on the light exit surface side of the light absorption layer 32 a little. Further, the light source light 35 (11) and the signal light 36 (13) are incident on the same surface in the light traveling direction. However, they are not necessarily the same surface, and may be slightly shifted.

  The deflection angle changes when the following conditions change.

1. 1. Position of the light absorption layer 32 of the thermal lens forming optical element 31 (19) with respect to the convergence (condensation) point of the light source light 35 (11) and the signal light 36 (13) of the first condenser lens 18. 2. Signal light power Signal light position (distance perpendicular to the optical axis of the light source light 35 (11) and the signal light 36 (13) at the condensing point of the first condenser lens 18)
4). 4. Thickness of the light absorption layer 32 of the thermal lens forming optical element 31 (19) 5. Signal light wavelength and light source light wavelength In addition to this, the dye concentration of the light absorption layer 32 also varies depending on the material of the light absorption layer 32, the condensing angle of the signal light 36 (13) and the light source light 35 (11) to the light absorption layer 32, and the like.

  In an example of the optical switch SW, the light source light 11 having a wavelength of 1550 nm is made incident on the input port 12 by a single mode quartz optical fiber having a core diameter of 9.5 μm, and the signal light 13 having a wavelength of 980 nm is made by a single mode quartz optical fiber having a core diameter of 9.5 μm. The light source layer 11 and the signal beam 13 are made almost parallel by the first collimating lens 15 and the second collimating lens 16 having a focal length of 8 mm, which are incident on the input port 14, and the light absorbing layer has a thickness of 500 μm. Were converged (condensed) by the first condenser lens 18 having a focal length of 8 mm and made incident on the thermal lens forming optical element 19 having a transmittance of 95% at a wavelength of 1550 nm and a transmittance of 0.2% at a wavelength of 980 nm.

  In FIG. 6, a light detector having a slit opening is provided in front of the branching mirror 22 in FIG. 2 in the direction perpendicular to the optical axis in the plane of the drawing, and the light of the light source light 11 measured by moving the light detector. The intensity distribution is shown. In FIG. 6, a line 41 (solid line connecting round points) is unpolarized light when no signal light is irradiated, and a line 42 (solid line connecting square points) is deflection when a signal light power of 7.8 mW is irradiated. The light line 43 (solid line connecting the dots) indicates the light intensity distribution of the deflected light when the signal light power of 12.9 mW is applied. In the case of deflected light 41 when irradiated with signal light power 7.8 mW, it overlaps with 42 in the case of non-deflected light at the bottom of the intensity distribution and is insufficiently separated from each other. 43 in the case of deflected light when 9 mW is irradiated is sufficiently separated from 42 in the case of non-deflected light. Therefore, it can be seen that the non-deflected light and the deflected light when the signal light power of 12.9 mW is irradiated by the branch mirror 22 can be separated. In FIG. 6, the signal light position (distance perpendicular to the optical axis of the light source light 11 and the signal light 13 at the condensing point of the first condenser lens 18) is 35 μm, and the signal light 13 and the light source light No. 11 was condensed at a position advanced about 30 μm from the light incident surface of the light absorption layer, and the thickness of the light absorption layer was 500 μm.

  FIG. 7 shows the relationship between the signal light power and the deflection angle. It can be seen that the deflection angle increases as the signal light power increases. In FIG. 7, the signal light position (distance perpendicular to the optical axis of the light source light 11 and the signal light 13 at the condensing point of the first condenser lens 18) is 35 μm, and the signal light 13 and the light source light 11 are The light was collected at a position advanced about 60 μm from the light incident surface of the light absorption layer.

  In the optical switch SW, the third collimating lens 20, the second condensing lens 23, and the third condensing lens 25 shown in FIG. 2 have the same focal length of 8 mm. This is the angle between the optical axis of the deflected light and the optical axis of the non-deflected light when it is not branched at 22. In the case of this example, the signal light power is 6.7 mW, about 6.7 degrees, the signal light power 12.9 mW is about 10.1 degrees, and the signal light power 18 mW is about 13.2 degrees. .

  In FIG. 8, the incident positions of the condensing points of the light source light 11 and the signal light 13 on the light absorbing layer 32 of the thermal lens forming optical element 31 (19) shown in FIG. 4 (referred to as “light absorbing layer position”). The relationship with a deflection angle is shown. In FIG. 8, the position of the light absorption layer on the horizontal axis is the position of the light incident surface on the light absorption layer 32 of the thermal lens forming optical element 31 (19) (the position of the signal light 13 and the light source light 11 with respect to the condensing point). is there. Point 0 is the position of the condensing point of the signal light 13 and the light source light 11, which is the state of FIG. 5b. The minus direction is the light traveling direction. At the plus position, the light source light 11 and the signal light 13 are collected in the light absorption layer 32 of the thermal lens forming optical element 31 (19). The vertical axis represents the deflection angle. In FIG. 8, the signal light power is about 12.9 mW, and the signal light position (relative to the optical axes of the light source light 11 and the signal light 13 at the condensing point of the first condenser lens 18 in FIG. The distance in the perpendicular direction) is 35 μm, and the thickness of the light absorption layer 32 is 500 μm.

  Further, FIG. 9 shows an incident position of the light source light 11 and the signal light 13 on the light absorption layer 32 of the thermal lens forming optical element 31 (19) shown in FIG. ) And an example of measurement data of the separation distance between the non-polarized light and the deflected light. When the incident position on the light absorption layer 32 is about 60 μm, the separation distance is close to 0, but when the position is shifted from this, the separation distance increases. In FIG. 9, the sign of the separation distance is defined such that the incident point of the light source light 11 is the origin (that is, 0 point) and the deflection direction is positive. In FIG. 9, the signal light power is 15.4 mW, the thickness of the light absorption layer 32 is 1000 μm, and the signal light position (the optical axes of the light source light 11 and the signal light 13 at the condensing point of the first condenser lens 18). (Distance in the direction perpendicular to) is 25 μm.

  The deflection angle also varies depending on the signal light wavelength and the light source light wavelength. The shorter the wavelength, the greater the deflection angle.

  Next, the configuration of the automatic circulation mechanism 4 of the data collection unit 3 will be described in detail with reference to FIG.

  As described above, the automatic circulation mechanism 4 is configured by connecting the first optical switch SW1 and the second optical switch SW2 having the same configuration as the optical switch SW described above in series.

  The first optical switch SW1 receives an input port 52 for capturing light source light 51, which is continuous (CW) light having a wavelength of 650 nm, and pulse signal light [gate light] 53 having a wavelength of 1550 nm, which is a trigger pulse. The input port 54 is provided. A first collimating lens 55 for converting incident light source light 51 into parallel light is disposed downstream of the input port 52, and an input signal light 53 for converting incident signal light 53 into parallel light is provided downstream of the input port 54. A second collimating lens 56 is disposed. A dichroic mirror 57 is disposed on the downstream side of the first collimating lens 55, and a mirror 58 that reflects parallel light from the first collimating lens 56 and changes its optical path is disposed on the downstream side of the second collimating lens 56. Has been. The dichroic mirror 57 transmits the parallel light from the first collimating lens 55, reflects the parallel light from the mirror 58, changes its optical path, and makes each of the parallel light. Here, the light source light 51 and the signal light 53 are optically arranged so as to be shifted in a direction perpendicular to the optical axis. A first condenser lens 59, a thermal lens forming optical element 60, a third collimator lens 61, a wavelength selective transmission filter 62, a branch mirror 63, and a second condenser lens 64 are arranged on the downstream side of the dichroic mirror 57, respectively. Has been. The first condenser lens 59 condenses (converges) the light source light 51 and the signal light 53 from the dichroic mirror 57 on the light absorption layer of the thermal lens forming optical element 60. Here, the light source light 51 and the signal light 53 are incident on the first condenser lens 59 at positions shifted in a direction perpendicular to the optical axis, and the optical path also enters the light absorption layer of the thermal lens forming optical element 60. The light is incident at a position shifted in a direction perpendicular to the light beam, and the condensing point is separated.

  The thermal lens forming optical element 60 emits the light source light 51 as unpolarized light that does not change the traveling direction when only the light source light 51 is incident, and the thermal lens when the light source light 51 and the signal light 53 are incident simultaneously. The light source light is emitted as deflected light whose traveling direction is changed. The third collimating lens 62 converts the emitted light source light 51 (unpolarized light and deflected light) and the signal light 53 into parallel light. The wavelength selective transmission filter 62 transmits the light source light 51 and cuts the signal light 53. A branch mirror 63 provided downstream of the optical wavelength selection filter 62 branches the non-deflected light and the deflected light, and the deflected light is reflected to change its optical path. Unpolarized light travels straight. A mirror 65 that further changes the optical path of the deflected light whose optical path has been changed and a third condenser lens 66 that condenses the light from the mirror 65 are disposed below the branch mirror 63 in the drawing. The first optical switch SW has two output ports 67 and 68. The output port 67 outputs 650 nm light of non-deflected light collected by the second condenser lens 64 when the signal light 53 is off. The output port 68 changes the optical path by the branch mirror 63 and the mirror 65 when the signal light 53 is turned on, and outputs 650 nm light of the deflected light condensed by the third condenser lens 66.

  The second optical switch SW2 has an input port 72 for taking in the light source light 71 that is continuous (CW) light having a wavelength of 1550 nm supplied from the laser oscillation device 2B of the monitoring device 2 through the optical cable C3, and the first optical switch SW2. An input port 74 for taking in 650 nm light output from the output port 68 of the optical switch SW1 as signal light [gate light] 73 is provided. A first collimating lens 75 for converting incident light source light 71 into parallel light is disposed downstream of the input port 72, and an input signal light 73 for converting incident signal light 73 into parallel light is disposed downstream of the input port 74. A second collimating lens 76 is disposed. A dichroic mirror 77 is disposed on the downstream side of the first collimating lens 75, and a mirror 78 that reflects the parallel light from the first collimating lens 76 and changes its optical path is disposed on the downstream side of the second collimating lens 76. Has been. The dichroic mirror 77 transmits the parallel light from the first collimating lens 75, reflects the parallel light from the mirror 78, changes its optical path, and makes each of the parallel light. Here, the light source light 71 and the signal light 73 are optically arranged so as to be shifted in a direction perpendicular to the optical axis. On the downstream side of the dichroic mirror 77, a first condenser lens 79, a thermal lens forming optical element 80, a third collimator lens 81, a wavelength selective transmission filter 82, a branch mirror 83, and a second condenser lens 84 are arranged. Has been. The first condenser lens 79 condenses (converges) the light source light 71 and the signal light 73 from the dichroic mirror 77 on the light absorption layer of the thermal lens forming optical element 80. Here, the light source light 71 and the signal light 73 are incident on the first condenser lens 79 at positions shifted in the direction perpendicular to the optical path, and the optical axis also enters the light absorption layer of the thermal lens forming optical element 80. The light is incident at a position shifted in a direction perpendicular to the light beam, and the condensing point is separated.

  The thermal lens forming optical element 80 emits the light source light 71 as unpolarized light that does not change the traveling direction when only the light source light 71 is incident, and the thermal lens when the light source light 71 and the signal light 73 are simultaneously incident. The light source light is emitted as deflected light whose traveling direction is changed. The third collimating lens 82 makes the emitted light source light 71 (unpolarized light and deflected light) and the signal light 73 parallel. The wavelength selective transmission filter 82 transmits the light source light 71 and cuts the signal light 73. A branch mirror 83 provided downstream of the optical wavelength selection filter 82 branches the non-deflected light and the deflected light, and the deflected light is reflected to change its optical path. Unpolarized light travels straight. Further, below the branch mirror 83 in the figure, a mirror 85 for further changing the optical path of the deflected light whose optical path has been changed, and a third condenser lens 86 for condensing the light from the mirror 85 are disposed. The second optical switch SW has two output ports 87 and 88. The output port 87 outputs 1550 nm light of non-deflected light collected by the second condenser lens 84 when the signal light 73 is off. The output port 88 changes the optical path by the branch mirror 83 and the mirror 85 when the signal light 73 is turned on, and outputs 1550 nm light of the deflected light collected by the third condenser lens 86. The optical output from the output port 48 is sent as a trigger pulse to the optical cable C1 and sent to the next data collection unit 3.

  The pulse width of the trigger pulse can be set to, for example, about several hundred μs to 1 ms, and the pulse height can be set to several mW to 10 mW, but is not limited thereto.

  Here, the thermal lens forming optical element 60 of the first optical switch SW1 and the thermal lens forming optical element 80 of the second optical switch SW2 used in the present embodiment will be described. Needless to say, the thermal lens forming optical element used in the present invention is not limited to these, and those described above can be used.

  As shown by the solid line in FIG. 11, the thermal lens forming optical element 60 has a wavelength band that shows transparency with respect to the light source light 51 with a wavelength of 650 nm and absorbs with respect to the signal light 53 with a wavelength of 1550 nm. It has a light absorption layer made of a dye. Here, Nippon Carlit Co., Ltd. product and CIR-960 are used.

  On the other hand, as shown by the chain line in FIG. 11, the thermal lens forming optical element 80 is transmissive for the light source light 71 having a wavelength of 1550 nm and is absorptive for the signal light 53 having a wavelength of 650 nm. A light absorption layer made of a dye having Here, copper (II) 2,9,16,23-tetra-tert-butyl-29H, 31H-phthalocyanine (Copper (II) 2,9,16,23-tetra-tert-butyl-29H, 31H-phthalocyanine ) Is used.

  The thermal lens forming optical elements 60 and 80 basically have the absorption and transmission wavelength characteristics as described above, and need only have a light absorption layer capable of forming a thermal lens. The heat transfer layer, the heat retaining layer, and the like can have various structures as described in Japanese Patent Application Laid-Open No. 2005-265986 related to the present inventors' application.

  In the present embodiment, the trigger pulse is circulated through the optical cable C3 as described above.

  In the present embodiment, as described above, since the collected data can be collected using the automatic circulator mechanism and the optical cable using the new optical switch without electrical processing, the system can be constructed at low cost, and the bad weather Even if the electric wire is cut or a power failure occurs under the above conditions, it is possible to continue monitoring the monitoring target. Further, since the system can be constructed with a small number of optical parts, the cost can be reduced.

  As mentioned above, although the automatic circulation collection type | formula data collection system which concerns on this invention has been demonstrated by one Embodiment, this invention is not limited to the said embodiment, A various deformation | transformation and change are possible.

  For example, in the above embodiment, the optical switch SW of the type shown in FIG. 2 is used as a basis. However, according to the present invention, the optical switch SW ′ of the type shown in FIG. In the same manner, an optical flip-flop circuit can be configured.

In FIG. 12, the same reference numerals are assigned to the same optical components as those in FIG. In FIG. 12, 95 is light source light, 96 is signal light, 96 is an input port, and 97 is an input port. In the switch SW ′ in FIG. 12, a two-core optical fiber ferrule 98 shown in FIG. 13 is used for optical input. The two-core optical fiber ferrule 98 includes a light source light emitting fiber 99 and a signal light emitting fiber 100. As these optical fibers 99 and 100, a clad layer of a single mode quartz optical fiber having a core of 9.5 μm was etched to a desired thickness with hydrofluoric acid. The portion to be etched was only a few mm of the tip of the optical fiber. The thickness “ω” of the optical fiber after etching can be determined by the following relationship with the distance “χ” perpendicular to the optical axis of the condensing point of the light source light and the signal light condensed on the light absorption layer.
(Formula 1)
ω = χ / m
Here, m is the imaging magnification of the first condenser lens 18.

  Even with such a configuration, the same effects as those of the above embodiment can be obtained, and the configuration of the light incident portion can be further simplified.

  In the above embodiment, the first optical switch SW1 uses the light source light 51 having a wavelength of 650 nm and the signal light 53 having a wavelength of 1550 nm, and the second optical switch SW2 uses the light source light 71 having a wavelength of 1550 nm and the signal light 73 having a wavelength of 650 nm. However, the wavelength relationship may be reversed between the first optical switch SW1 and the second optical switch SW2.

  Moreover, although the wavelength of 650 nm and 1550 nm was utilized in the said embodiment, it is not limited to this, As long as the thermal lens can be formed as mentioned also in description of the optical switch SW of FIG. Can be used as a pair.

It is the figure which showed typically the structure of the automatic circulation collection type data collection system which concerns on one Embodiment of this invention. It is a principle explanatory view of the optical switch used for the automatic circulation mechanism of the data collection unit in the automatic circulation collection type data collection system of FIG. It is a figure which shows the condition of the emission of light source light when there is no signal light and when there is signal light, when condensing light source light and signal light to the same place to the light absorption layer of a thermal lens formation optical element. . It is sectional drawing which shows schematic structure of a thermal lens formation optical element. It is explanatory drawing of the condition where the light source light in the case of not condensing deflects. It is explanatory drawing of the condition where the light source light at the time of condensing deflects. It is a figure which shows light intensity distribution when not irradiating signal light, and when irradiating by changing the power of signal light. It is a graph which shows the relationship between signal light power and a deflection angle. It is a graph which shows the relationship between the position of a light absorption layer, and a deflection angle. It is a graph which shows the relationship between the separation distance of non-deflected light and deflected light. It is a figure which shows typically the structure of the automatic circulation mechanism of the data collection unit in the automatic circulation collection type data collection system of FIG. It is explanatory drawing of the wavelength characteristic of the light absorption layer used for a thermal lens effect optical element. It is a figure which shows schematic structure of another example of the optical switch used for the automatic circulation collection type data collection system of this invention. It is a conceptual diagram of the 2 core optical fiber ferrule used for the optical switch of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic circulation collection type data collection system 2 Monitoring apparatus 2A Uninterruptible power supply 2B Laser oscillation apparatus 3 Data collection module 3A Photovoltaic battery 3B Rechargeable battery 4 Automatic circulation mechanism 5 Data collection unit 6 Control part 7 Communication control part 8 E / O part C1, C2, C3 Optical cable SW1, SW2, SW3 Optical switch 51, 71 Light source light 52, 54, 72, 74 Input port 53, 73 Signal light 55, 56, 61, 75, 76, 81 Collimating lens 57, 77 Dichroic mirror 58, 65, 78, 85 Mirror 59, 64, 66, 79, 84, 86 Condenser lens 60, 80 Thermal lens forming optical element 62, 82 Wavelength selective transmission filter 63, 83 Branch mirror 67, 68, 87, 88 Output port

Claims (1)

It consists of a monitoring device and a data collection module located at each site connected by an optical cable.
The monitoring device includes a trigger pulse generator for sending a trigger pulse for collecting data at a predetermined timing to each data collection module via an optical cable, and a collected data collection unit for receiving collected data from each data collection module via an optical cable And a control unit that transmits a control signal for data collection to each data collection module,
Each data collection module is provided with an identification code. Each data collection module includes an automatic circulation mechanism including a first optical switch and a second optical switch, and a data collection unit for collecting data at each base. A control unit connected to the data collection unit and the optical cable, and a third optical switch for controlling on / off of the connection between the control unit and the optical cable,
Each of the first optical switch and the second optical switch inputs light source light and signal light having a wavelength different from the light source light, and turns on / off the output of the light source light by turning on / off the signal light. It consists of a light control type optical switch of the control method,
When the automatic circulation mechanism receives a trigger pulse from the monitoring device, it turns on the third switch and causes the control unit to transmit the data collected by the data collection unit to the monitoring device together with the identification code to the monitoring device via the optical cable. An automatic loop-collecting data collection system that sends pulses to the next data collection module via an optical cable,
The first optical switch
A first signal input unit that inputs a first light source light that is continuous light having a first wavelength λ1 and a first signal light that is pulsed light having a second wavelength λ2.
A first thermal lens-forming optical element having a first light absorption layer having a wavelength band that absorbs the first signal light and transmits the first light source light;
The first light absorbing layer includes a first light condensing unit that condenses the first signal light and the first light source light with different condensing points in a direction perpendicular to the optical axis,
The first thermal lens forming optical element has a heat based on a refractive index distribution reversibly generated due to a temperature rise occurring in a region where the first light absorption layer absorbs the first signal light and its peripheral region. By using the lens, when the first signal light is not irradiated and a thermal lens is not formed, the first light source light is emitted as unpolarized light that does not change the traveling direction, and the first signal light is irradiated. When the thermal lens is formed, the state of emitting the first light source light as the deflected light whose traveling direction is changed is realized in correspondence with the presence or absence of the irradiation of the first signal light,
Further, of the first light source light emitted from the first thermal lens forming optical element, the non-deflected light is output from the first output port, and the deflected light is output from the second output port. With an optical path switching unit,
The second optical switch
The first light source light having the first wavelength λ1 output from the second output port of the first optical switch is taken in as the second signal light, and the second signal light and the second wavelength λ2 are continuously generated. A second signal input unit that receives a second light source light that is light;
A second thermal lens forming optical element having a second light absorption layer having a wavelength band that absorbs the second signal light and transmits the second light source light;
A second condensing part for condensing the second signal light and the second light source light on the second light absorbing layer with the condensing points different from each other in the direction perpendicular to the optical axis;
The second thermal lens forming optical element has a heat based on a refractive index distribution reversibly generated due to a temperature rise occurring in a region where the second light absorption layer absorbs the second signal light and its peripheral region. By using the lens, when the second signal light is not irradiated and the thermal lens is not formed, the second light source light is emitted as unpolarized light, and the second signal light is irradiated to form a thermal lens. If so, the state of emitting the second light source light as the deflected light is realized corresponding to the presence or absence of irradiation of the second signal light,
Further, the second thermal lens forming optical element outputs a second light source that outputs non-deflected light from the first output port and outputs deflected light from the second output port among the output second light source light. With an optical path switching unit,
The first signal input unit of the first optical switch is connected to the optical cable, takes the trigger pulse as the first signal light,
The first output port of the first optical switch is connected to the third optical switch;
A second output port of the first optical switch is connected to a second signal input of the second optical switch;
The second output port of the second optical switch is connected to an optical cable.

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