JPH0693052B2 - Optical power adjustment method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an optical power adjustment method for optically coupling an optical fiber with an optical semiconductor element such as a light emitting element or a light receiving element used in optical communication and the like. Is.

(Prior Art) Conventionally, a light emitting diode (LE
D), a light emitting element such as a semiconductor laser diode (LD),
Photodetectors such as photodiodes (PIN-PD, APD) usually use optical lenses (hereinafter referred to as lenses), converging rod lenses, and converging rod lenses in order to obtain maximum optical coupling efficiency with the optical fiber that is the transmission medium. The adjustment is made via a ball lens.

FIG. 8 is an overall configuration diagram of the optical power adjusting device, FIG. 9 is a cross-sectional view of an optical semiconductor element and an optical connector portion, FIGS. 10 and 11.
The figure is a flowchart showing a conventional optical power adjustment method.

Hereinafter, a conventional optical power adjusting method for optical coupling will be described with reference to these drawings.

First, the optical semiconductor device 1 is clamped or held in the optical power adjusting device shown in FIG. 8 via a jig (not shown). The jig is configured to interlock with the adjusting device, and the position of the optical semiconductor element 1 can be moved to a desired position through the jig by operating the adjusting device.

On the other hand, on the optical fiber 5 side, a lens holder 3 in which the lens 2 is fixed by a fixing agent and a collimator 4 are screwed and connected. Therefore, the lens holder 3 including the collimator 4 is firmly fixed via a jig (not shown).

Hereinafter, a case where a light emitting element is used as an optical semiconductor element will be described.

In this state, the end point of the optical fiber 5 is connected to a measuring instrument for displaying the optical coupling state so that the state of the optical power incident through the lens 2 can be constantly displayed.

Therefore, a voltage is applied between the anode 6 and the cathode 7 of the light emitting element, and the light emitting element emits light by energizing with a forward bias. Note that a constant current source is used as this power source to supply a constant current.

Further, in FIG. 8, 8 is a lens holder holding jig, 9 is a fixing jig and a handle for fixing the jig, 10 is an optical semiconductor element clamping jig, 10-1 is a concave portion, 11-1 is a holding lever. , 11-2 is a lock lever, 11-3 is a bias spring, 12
Is a precision motor for Z-axis drive, 13 is a precision motor for X-axis drive, 14 is a precision motor for Y-axis drive, 15 is a Z stage, 17
Is an electronic control unit.

Here, a control device for adjusting the optical power will be described.

A precision motor 13 is used to move the set optical semiconductor element 1 in the X-axis direction, a precision motor 14 is also used to move the optical semiconductor element 1 in the Y-axis direction, and a precision motor 12 is also used to move it in the Z-axis direction. And these motors
It is controlled by an electronic control unit 17 having a CPU (central processing unit) 18. To explain this point in more detail, the electronic control unit 17 includes a CPU 18, a memory 19, and an I / O interface 2
0, KB / CRT21, printer 22, etc. The electronic control unit 17 is an optical measuring device connected to the end point of the optical fiber 5.
Measured values from 16 are read. Furthermore, the output from the I / O interface 20 is
It is connected to 2,13,14.

Therefore, first, the precision motors 13 and 14 connected to the electronic control unit 17 are driven to position the clamped optical semiconductor element 1 above the position where the lens holder 3 shown in FIG. 8 is fixed. To move.

Next, the adjustment procedure using this adjustment jig will be described with reference to the flowchart of the main routine of FIG.

First, the initial setting is performed (step), and then the parts set is confirmed (step). Next, the precision motor 12 is driven to gradually lower the Z stage 15 (step). At that time, it is measured whether or not the optical power incident from the lens 2 is close to the target value (standard value) (step), and if it is already close to the target value, the process moves to a fine movement routine in which the movement pitch is one digit smaller. Next, the quality of the optical semiconductor element is determined (step). This is because if the optical semiconductor device is energized and brought close to the vicinity of the lens 2, the minimum value that can be entered in the optical measuring device 16 can be detected in advance, and it can be determined by whether or not the value has been reached. If it is determined that light emission or light reception is not performed, the abnormality of the optical semiconductor element is displayed on the CRT 21 or the printer 22 (step). Then, it is again judged whether or not the value is close to the standard value (step). If NO, the coarse movement routine is skipped and the fine movement routine is performed. If the optical power is far from the standard value, the coarse movement routine (step) is directly started.

Here, the coarse movement subroutine will be described in detail with reference to FIG.

First, when the coarse movement routine is entered, the built-in counter increments by 1 and becomes +4. Even if the coarse movement is repeated 4 times (steps), the value still does not come close to the standard value.
The optical semiconductor element is determined to be defective, and an abnormality is displayed (step). Next, if the coarse movement is not repeated four times, one pulse is generated in the + X direction, the precision motor 13 is driven, and one pitch is moved in the + X direction (step). In this case, the measured value from the optical measuring device 16 is read into the electronic control unit 17 (step), compared with the previously read value, judged (step), and as a result, if the value improves, Furthermore, the pitch is moved in the + X direction, and the pitch is sequentially moved. When the comparison result decreases, the position is moved by +1 pinch in the -X direction (step), and the position is set as the adjustment position. With such adjustment method, -X direction, + Y,-
Adjust for each direction of Y, + Z, -Z,
Finish the adjustment at the position where the power is maximum in each direction,
Finish coarse adjustment.

When the coarse adjustment is completed, the process returns to the main routine shown in FIG. Then, when the optical power of the optical semiconductor element 1 at this time is sufficiently incident from the lens 2 and is not close to the standard value, the coarse movement adjustment (step) is performed again. When the value is sufficiently close to the standard value, the control moves to the fine movement routine (step). The method of adjusting the fine movement routine (step) is the same as the previous coarse movement routine, except that the pitch width for moving the optical semiconductor element 1 is set to 1/10 of the pitch width in the coarse movement adjustment. By repeating this fine adjustment in the X, Y, and Z directions as in the case of coarse adjustment, the standard value can be cleared.

Furthermore, in the ultra-fine movement adjustment, the pitch width is narrowed to 1/10 of the pitch width in the previous fine movement adjustment and 1/100 of the coarse movement adjustment, and the position where the optical power obtained from the optical measuring instrument 16 is maximized is set. Find out.

The case where the optical semiconductor element 1 is a light emitting element has been described above. Next, an adjusting method when the optical semiconductor element is a light receiving element will be described.

The method of adjusting the light-receiving element is similar to that of the light-emitting element, except for the following points.

First, the above-mentioned light emitting element is set instead of the light receiving element. That is, a stabilizing light source (not shown) is connected to an optical connector in which the optical fiber 5 is paired by screwing, and the light emitted from the stabilizing light source is propagated to the optical fiber 5 and received via the lens 2. Light is incident on the element. Then, an electromotive force is induced between the anode 6 and the cathode 7 to generate a current, and the current value is read through a measuring circuit with a measuring instrument such as an ammeter or a voltmeter to maximize the value. Set. After the light receiving element is set, the light measuring element 16 for reading the optical power becomes an ammeter or a voltmeter in the same manner as the method for adjusting the light emitting element.

Then, similarly, coarse movement adjustment in the X, Y, and Z directions and then fine movement adjustment are performed, and final adjustment is performed to a position where the maximum current value or voltage is obtained, so that the optical coupling efficiency is maximized.

(Problems to be Solved by the Invention) However, in the above-described conventional adjustment method, there are many useless steps, and the work time for adjustment is prolonged by repeatedly passing on the same coordinate, and further, such adjustment In the method, there is a problem that the optical power of the optical semiconductor element cannot be adjusted to the standard value and the processing ends. On the contrary, despite satisfying the standard value sufficiently,
Since all adjustment processes are not completed, there is a problem in that unnecessary steps are spent and time is wasted.

Further, apart from these, there is a problem that adjustment cannot be performed for an optical semiconductor element whose emission or light receiving pattern is completely different from the conventional one, which is not technically satisfactory.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned problems and provide an optical power adjusting method capable of more quickly and accurately adjusting optical coupling.

(Means for Solving the Problems) In order to solve the above problems, the present invention adjusts an optical power having an optical connector having an optical transmission medium and aligning an optical semiconductor element with the optical transmission medium. In the method, the initial motion is set, then 10μ from the coarse motion stage of 100μm order.
In order to search for a position where the optical power from the optical semiconductor element is maximized in the X-axis, Y-axis, and Z-axis directions by switching the m-order fine movement stairs to the 1 μm-order ultrafine movement stage in multiple stages, , If the optical power value is sufficiently close to the standard value, the process is moved to the ultrafine movement stage, the optical power value being adjusted in the search of the coarse movement stage, the fine movement stage and the ultrafine movement stage is sequentially read, and each stage is read. When the adjustment state for the target value or the standard value in is determined, and when each target value is reached in the coarse movement stage and the fine movement stage, the intermediate process is skipped and the process proceeds to the next adjustment stage. When the optical power value is sufficiently close to the standard value, the step is moved to the ultrafine movement step, and in the search in each axis direction in each step, the step is moved to one of the axes by one pitch to reach the target value. If it is judged not to be done, in the step of shifting to the search for the other axis, and reading the optical power in the ultrafine movement stage to lower the Z axis, in proportion to the difference in optical power from the standard value, The reduction width of the Z axis is changed.

(Operation) According to the present invention, as described above, the initial setting is performed, and then 10
Search for the position where the optical power from the optical semiconductor element is maximum in the X-axis, Y-axis, and Z-axis by switching to multiple stages from coarse movement stage of 0 μm order, fine movement stage of 10 μm order, and ultra fine movement stage of 1 μm order. In doing so, first, in the initial setting, when the optical power value is sufficiently close to the standard value, the process is moved to the superfine movement stage, so that adjustment that may occur only rarely when the Z stage is lowered is performed. When getting on the coordinates of unnecessary and strong power, the pitch width is wide in the movement of 100 μm pitch performed in the coarse movement routine, so if the optical power value deteriorates a little, it will take a lot of time to return to the original coordinates again. Although it takes time, it is possible to eliminate such a waste of search time.

Further, in the initial setting, when the optical power value is sufficiently close to the standard value, there is a step of shifting to the ultrafine movement stage, so that adjustment that may occur only rarely when the Z stage is lowered is performed. When it is set on the coordinates of unnecessary and strong optical power, the pitch width is wide in the movement of 100 μm pitch performed in the coarse movement routine, so if the optical power value deteriorates a little, it may be necessary to return to the original coordinates again. Although it takes a lot of time, it is possible to eliminate such a waste of search time.

Further, the optical power value being adjusted in the search of the coarse movement stage, the fine movement stage and the ultrafine movement stage is sequentially read, and the adjustment state with respect to the target value or the standard value at each stage is judged each time, and the coarse movement stage and the fine movement stage are determined. In the case where each target value is reached in step 1, there is a step of skipping an intermediate step and shifting to the next adjustment step, so that an unnecessary adjustment step can be omitted, and the optical semiconductor element and the optical transmission The work of adjusting the optical coupling with the medium can be achieved more quickly and accurately.

Further, when the optical power value is sufficiently close to the standard value in the coarse movement stage, there is a step of shifting to the ultrafine movement stage, so that many adjustment steps in the fine movement stage can be omitted, The work of adjusting the optical coupling between the semiconductor element and the optical transmission medium can be achieved more quickly and accurately.

Also, in the search in each axial direction in each of the above steps,
If it is determined that the target value is not approached by stepping one axis to one of the axes, the step of shifting to the other of the axis is included. Therefore, -X, -Y, -Z is included. By avoiding the duplication of steps when shifting to the direction, the adjustment work of the optical coupling between the optical semiconductor element and the optical transmission medium can be achieved more quickly and accurately.

Furthermore, in the step of reading the optical power in the ultrafine movement stage and lowering the Z axis, there is a step of changing the amount of reduction of the Z axis in proportion to the difference in the optical power from the standard value.
In this ultra-fine movement stage, the pitch width per step is 1μ
Since it is as small as m, the change in the optical power is smaller than the coarse movement and the fine movement that have been performed so far, and it is difficult to reach the standard value when the normal steps are sequentially performed. Therefore, adjustment is performed by taking a large number of steps on the Z axis in the coarse movement stage and the fine movement stage up to now, and by forcibly lowering it by several μm based on the optical power data at the time of the adjustment, This difference in the number of steps between the X and Y directions can be eliminated, and the number of huge steps used in the Z direction at the ultrafine movement stage can be reduced.

It is also possible to lower the Z axis of the initial adjustment start coordinates here, but if it is lowered in advance, there is a risk of contact with the lens and either one being damaged, and doing this is extremely dangerous.

Thus, by using this subroutine, it is possible to reduce the huge number of steps used in the Z direction.

(Example) Hereinafter, the Example of this invention is described in detail, referring drawings.

FIG. 1 is a flow chart of a main routine showing the optical power adjusting method of the present invention, FIG. 2 is a flow chart of its coarse adjustment subroutine, FIG. 3 is a flow chart of a subroutine for moving the pitch to each direction, and FIG. FIG. 5 shows a flowchart of a subroutine for lowering the Z axis, and FIG. 5 shows a flowchart of a subroutine for searching the XY plane. The configuration of the optical power adjusting device is the same as that of the conventional one shown in FIG. 8, and the optical semiconductor device 1 and its attachment to the clamp jig 10, and the lens holder 3 and its holding jig 8 are Since the mounting method and the configurations of the precision motors 12, 13, 14 and the electronic control unit 17 are the same as the conventional ones, their description will be omitted.

Therefore, the optical power adjusting method of the present invention will be described with reference to the flowchart of the main routine of FIG.

First, the initial setting is performed (step), then the origin return is performed (step), and the parts set is confirmed (step). Then, the precision motor 12 is driven to gradually lower the Z stage (Z axis) 15 (step). At that time, it is determined whether or not the optical power incident from the lens 2 is sufficiently close to the standard value (step).

In this initial setting, if it is already close to the standard value,
The process moves to the ultrafine movement routine in which the moving pitch is two orders of magnitude smaller. This is because when the Z stage 15 is moved down to a coordinate of strong power that does not require adjustment that may occur very rarely when the Z stage 15 is moved down, the pitch width is wide in the movement of 100 μm pitch performed in the coarse movement routine. When the power value deteriorates a little, it takes a lot of time to return to the original coordinates again, but this is to eliminate such waste of search time.

Next, the quality of the optical semiconductor element is determined (step).
This is because if the optical semiconductor element is energized and brought close to the lens 2, the minimum value that can be entered into the optical measuring device 16 can be detected in advance. Therefore, depending on whether or not the value has reached (-50 to 60 dBm), it is easy. You can judge. If light emission or light reception is not performed, the abnormality of the optical semiconductor element is displayed on the CRT 21 or the printer 22 (step). If the optical semiconductor element is normal, the next step is performed.
Then, it is again judged whether or not it is away from the standard value (step), and if NO, the coarse movement routine is skipped and the fine movement routine is started. If the optical power is far from the standard value, the coarse movement routine (step) is directly started.

Here, the coarse movement routine will be described in detail with reference to FIG.

First, when this coarse movement routine is entered, the built-in counter increments by 1, and if this counter becomes +4, the coarse movement becomes 4
Even after repeating the step (step), when the value of the optical power before the coarse movement subroutine is entered, an abnormal display (step) is displayed.

Here, a subroutine for moving one pitch in each direction to move in the + X direction is entered (step). This subroutine for moving one pitch will be described in detail with reference to FIG.

First, when entering this subroutine, it is judged whether or not the current value of the optical power has reached the target value at that stage (step). If NO, normal reading is performed, one pulse is generated in the + X direction, the precision motor 13 for driving the X-axis is driven, and one pitch in the + X direction, that is, 100 μ.
After moving by m (step), the measurement value from the optical measuring device 16 is sent to the electronic control unit 17 (step), and this subroutine is exited. At this time, when a larger value of the optical power is shown, the MAX value coordinate value is stored (step). On the other hand, if YES in the step, the coarse pitch subroutine is ended by skipping the 1-pitch moving subroutine. This is not very effective at the start of the adjustment, but the adjustment has entered the middle stage and the optical power value has reached the target value sufficiently, and further improvement of the optical power cannot be expected even if the coarse movement subroutine is continued. If it is determined that the value is to be transferred to the next fine movement subroutine. In the past, each coarse and fine subroutine could not be completed without going through all the steps, but as a result, when the optical power reaches the target value, the subroutine currently being executed can be immediately terminated. it can.

Here, the description will be continued by returning to the flowchart of the coarse movement subroutine of FIG. 2 again.

In the next step, it is judged whether the value of the optical power measured after the movement this time is larger than the value of the previous optical power (step), and if YES, the counter of the number of repetitions in the + X direction is set to +1. After (step), again,
Enter a subroutine that moves one pitch in the + X direction. If NO here, the optical power is not improved in this direction and the process proceeds in the -X direction.

Next, it is judged whether or not the previous counter in the + X direction is 2 or more (step), and if YES, it is moved one pitch in the -X direction (step), and the moving direction is moved to the + Y direction. If NO, enter a subroutine that moves one pitch in the -X direction (step), then compare the previous optical power measured value with the value measured this time (step). If it improves, 1 again
Enter the routine to move the pitch and continue until the measured value of the optical power deteriorates. When that is completed, it advances one pitch in the + X direction, which is the opposite of the direction it has been so far (step).
In the conventional method, all directions (+ X, −X, + Y, −Y, + Z, −
With respect to Z), if the optical power deteriorates, it is moved back one pitch in the direction opposite to that direction and moved to the next axial direction, but in each direction on the-side, it is twice or more in the previous adjustment axis. If it moves 1 pitch at a time, it means the coordinates that should have already passed, and if the optical power improves by more than 2 movements, it is in the range of measurement error, and there is no meaningful adjustment action. Become.

The adjustment method in the + X to −X direction has been described above from step to step. Similarly, the adjustment method is shown from step to step in the + Y to −Y direction, and this adjustment is the same as the adjustment of the X axis described above. So
Detailed description is omitted here.

Then, in the next step, the presence or absence of light emission or light reception of the optical semiconductor element is determined again (step). Here, the optical measuring device 16 and the optical fiber 5 are not connected,
If the adjustment is started by mistake, it is a preliminary step when it is not detected by the first detection of the main routine. Also here, as in the previous time, if an abnormality is recognized in the optical semiconductor element, an abnormality display is made (step) and the present adjustment is stopped.

In the next step, the adjusted + X, −X, + Y, −Y,
The adjustment for each direction of + Z and -Z is completed, and it is determined whether or not the target value is reached (step).
Here, if the target value is not reached, the number of times of use of this subroutine is incremented by 1 (step), and then the process returns to the first step.

Here, the step is ignored because it is used only in the subsequent routine.

If the optical power value reaches the target value, the coarse movement subroutine is ended. When the coarse movement subroutine is completed, the process returns to the main routine shown in FIG. Then, the optical power of the optical semiconductor device 1 when returning returns to the lens 2, propagates through the optical fiber 5 and is transmitted to the optical measuring device 16, and the output is about 10 dB higher than the target value in the coarse movement subroutine. If (step), it jumps over the fine movement subroutine (step) and shifts to the ultrafine movement subroutine (step). If not, the process moves to the fine movement subroutine (step). In this fine movement subroutine, the adjustment method is the same as the coarse movement routine described so far, but the pitch width for moving the optical semiconductor element 1 is 1/10 of the pitch width in the coarse movement adjustment, that is, 10 μm.
The difference is that it is set to m. Also, the target value here is
Use a value 10 dB higher than the target value used in the coarse movement subroutine. The target value can be cleared by repeating this fine movement adjustment in the X, Y, and Z directions as in the case of coarse movement adjustment.

Further, in the ultra fine movement adjustment (step), the pitch width is narrowed to 1/10 of the pitch width in the previous fine movement adjustment and 1/100 of the coarse movement adjustment, that is, 1 μm, and is obtained from the optical measuring device 16. Find the position where the optical power is maximum. Further, the target value here is a standard value, which is 5 to 7 dB higher than the target value of the fine adjustment. Here, a routine (step) shown in a frame surrounded by a dotted line in FIG. 2 is added to the hyperfine movement subroutine.

A subroutine for reading the optical power and lowering the Z-axis will be described in detail with reference to FIG.

First, the current optical power of the optical semiconductor element 1 is
If the distance is 4 dB or more (step), lower the Z axis by 50 μm from the current coordinate (step). If the distance is about 3 dB (step), set the Z axis to 30
It descends by μm (step) and returns to the ultrafine movement subroutine. Then, if they are separated by 2 dB (step), the Z axis is lowered by 20 μm (step). Then, the process returns to the ultrafine movement subroutine. Since this subroutine has a fine pitch width of 1 μm per step, the change in the optical power is smaller than the coarse movement and the fine movement so far, and does not easily reach the standard value. Therefore, it is known from the adjustment data so far that the Z axis, that is, the Z direction is adjusted by taking a larger number of steps than the other directions, and the Z direction is forcibly lowered. This is to remove the difference in the number of steps from the X and Y directions. It is also possible to lower the Z axis of the initial adjustment start coordinates here, but if it is lowered in advance, there is a risk of contact with the lens and damaging either of them.
Doing this is very dangerous. Thus, by using this subroutine, it is possible to reduce the huge number of steps used in the Z direction.

In the ultra-fine movement subroutine, the subroutine for lowering the Z-axis is often used to realize a short adjustment time. Then, the process again returns to the main routine shown in FIG. There, it is moved to the coordinate showing the maximum optical power among the coordinate points adjusted so far (step). This is because the coordinates showing a larger optical power are stored in the memory 19 by the processing performed in the step of FIG.
From this coordinate, the distance from the current coordinate is calculated, and the coordinate is moved to the coordinate showing the maximum value. This can be done only by moving to a coordinate with a larger value compared to the previous optical power value, but if the next value is smaller than this time, it will return to the previous coordinate. Therefore, an error may occur. That is, it does not exactly return to the previous optical power value. This may be about 0.5 dB lower than the maximum value by the end of the adjustment, and it is added for the purpose of correcting this.

As described above, the adjustment of the optical power is completed and the work is displayed. After the optical power of the optical semiconductor device 1 is adjusted, the movement amount in the X and Y directions and the optical power loss are measured and plotted. For example, the apex of a parabola shown in FIG. 6 can be found. become.

Further, the case where the optical semiconductor element is a light emitting element has been described so far, but in the case of a light receiving element, particularly an optical semiconductor element such as a PIN-photodiode, when plotted in the same manner as in FIG.
It becomes as shown in FIG. In this case, the coarse movement subroutine used for the light emitting element cannot be used. Because the loss curve in the case of the light emitting element is a parabola, X, Y, Z
The optical power changed regardless of the position in the direction, and the amount of change could be adjusted.

However, in the light receiving element, there is a certain place of the optical power regardless of the change of the coordinates, and the coarse movement subroutine is completely ineffective here. Therefore, as shown in FIG.
We devised a subroutine to search the XY plane.

Here, the subroutine for exploring the XY plane will be described in detail with reference to FIG.

First, when this subroutine is entered, it is advanced by one pitch in the + Y direction (step). Then, the value of the optical power at this time is stored.

Similarly, 1 pitch (step) in the + X direction, +
2 pitches (steps) in the Y direction, 2 pitches (steps) in the -X direction, 3 pitches (steps) in the + Y direction,
After moving by 3 pitches (steps) in the + X direction and 4 pitches (steps) in the -Y direction, the coordinates are moved to the coordinates showing the maximum optical power value on all of these coordinates (steps).

As a result, the optical power in FIG. 7 changes completely, and it is possible to pass through a portion where the optical power does not change. This is the end of the subroutine for exploring the XY plane. Then, the process returns to the main routine, but thereafter, the sub-routines of fine movement and ultra-fine movement can be used as in the case of the light emitting element. Thereby, even when the optical semiconductor element is a light receiving element, the optical power can be adjusted.

As described above, it is possible to find the position where the optical power is maximum regardless of whether the optical semiconductor element is a light emitting element or a light receiving element.

The present invention is not limited to the above embodiment,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described in detail above, according to the present invention, the following effects can be achieved.

(1) Initial setting, then switch from multistage to 100μm-order coarse movement, 10μm-order fine movement, and 1μm-order ultrafine movement, and from the optical semiconductor device in the X-axis, Y-axis, and Z-axis directions. In searching for the position where the optical power of the above becomes maximum, first, in the initial setting, when the optical power value is sufficiently close to the standard value, the stage is moved to the ultrafine movement stage, so the Z stage is lowered. If the optical power value is slightly deteriorated because the pitch width is wide in the movement at the 100 μm pitch that is performed in the coarse movement routine when it is set on the coordinate of strong power that does not require adjustment that may occur rarely at the time However, it takes a lot of time to return to the original coordinates again, but it is possible to eliminate such a waste of search time.

(2) The optical power value during the adjustment in the search of the coarse movement stage, the fine movement stage and the ultrafine movement stage is sequentially read, and the adjustment state with respect to the target value or the standard value at each stage is determined each time, and the coarse movement stage and the fine movement are performed. When each target value is reached in the stage, the intermediate process is skipped and the process is moved to the next adjustment stage, so that unnecessary adjustment steps can be omitted, and the optical semiconductor element and the optical transmission medium can be omitted. The optical coupling adjustment work can be achieved more quickly and accurately.

(3) When the optical power value is sufficiently close to the standard value in the coarse movement stage, the process is shifted to the ultrafine movement stage, so that many adjustment steps in the fine movement stage can be omitted, and the optical semiconductor element can be omitted. The adjustment work of the optical coupling between the optical transmission medium and the optical transmission medium can be achieved more quickly and accurately.

(4) In the search in each axial direction in each of the above steps,
When it is determined that the target value is not approached by stepping one pitch to one of the axes, the search is moved to the other of the axis. Therefore, it moves in the -X, -Y, -Z directions. By avoiding the duplication of the steps in performing the process, the adjustment work of the optical coupling between the optical semiconductor element and the optical transmission medium can be achieved more quickly and appropriately.

(5) In the step of reading the optical power in the ultrafine movement stage and lowering the Z axis, the reduction width of the Z axis is changed in proportion to the difference in the optical power from the standard value. Since the pitch width per step is as small as 1 μm, the change in the optical power is smaller than the coarse movement and the fine movement so far, and it is difficult to reach the standard value when the normal steps are sequentially performed. Therefore, adjustment is performed by taking a large number of steps on the Z axis in the coarse movement stage and the fine movement stage up to now, and by forcibly lowering it by several μm based on the optical power data at the time of the adjustment, This difference in the number of steps between the X and Y directions can be removed,
It is possible to reduce the huge number of steps used in the Z direction in the ultrafine movement stage.

Therefore, it is possible to eliminate the conventional useless steps as much as possible, simplify the adjustment itself, and shorten the adjustment time. In addition, due to the conventional dispersion of optical semiconductor elements, there is no problem that adjustment can be stopped midway and adjustment becomes impossible, and it becomes possible to perform adjustment for all optical semiconductor elements, making quick and reliable adjustment. It has become possible.

Further, according to the above (5), the optical power can be adjusted even when the loss curve of the optical semiconductor element is different.

Furthermore, although the present invention is mainly used for assembling optical modules and the like, it is also applicable to fusion bonding of optical fibers after optical power adjustment.

[Brief description of drawings]

FIG. 1 is a flowchart of a main routine showing an optical power adjusting method of the present invention, FIG. 2 is a flowchart of a coarse adjustment subroutine thereof, FIG. 3 is a flowchart of a subroutine for moving one pitch in each direction, and FIG. 4 is an optical power. Of the subroutine to read in and lower the Z-axis,
FIG. 5 is a flowchart of a subroutine for searching the XY plane, FIG. 6 is a loss characteristic diagram relating to the distance of the semiconductor element (No. 1), FIG. 7 is a loss characteristic diagram relating to the distance of the semiconductor element (No. 2), and FIG. Is an overall configuration diagram of the optical power adjustment device,
FIG. 9 is a sectional view of an optical semiconductor element and an optical connector portion, and FIGS. 10 and 11 are flowcharts showing a conventional optical power adjusting method.

Claims (1)

[Claims] 1. An optical connector having an optical transmission medium is fixed,
In the optical power adjusting method for aligning an optical semiconductor element with the optical transmission medium, firstly set, and then from the coarse movement stage of 100 μm order,
In searching for a position where the optical power from the optical semiconductor element is maximized in the X-axis, Y-axis, and Z-axis directions by switching from 0 μm order fine movement stage to 1 μm order ultra fine movement stage, , If the optical power value is sufficiently close to the standard value, the process is moved to the ultrafine movement stage, the optical power value being adjusted in the search of the coarse movement stage, the fine movement stage and the ultrafine movement stage is sequentially read, and each stage is read. Judge the adjustment state for the target value or standard value in, when each target value is reached in the coarse movement stage and the fine movement stage, skip the intermediate process and shift to the next adjustment stage,
When the optical power value is sufficiently close to the standard value in the coarse movement stage, the process is moved to the ultrafine movement stage, and in the search in each axis direction in each stage, the target is made by stepping one pitch to one of the axes. If it is judged that the value does not approach,
In the step of shifting to the other search of the axis and reading the optical power in the ultrafine movement stage and lowering the Z axis, the reduction width of the Z axis is changed in proportion to the difference of the optical power from the standard value. An optical power adjusting method characterized in that