JP2001358383A - Optical origin-adjusting device and initial adjustment method of optical origin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To match the optical origin of a position detector that is composed by so called PSD in initial adjustment to the center of a machine easily, accurately, and rapidly. SOLUTION: A position detector 21 for detecting the position of an optical origin to the detection surface of a reference laser beam that is applied by photocurrents I1 and I2 is set to tool that is mounted in a cavity having a YAG rod, and detection circuits 29 and 30 having variable resistors 27 and 28 are connected to the position detector 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical origin adjusting device for adjusting the optical origin of a PSD position detector used for adjusting the optical axis of a laser device having a multi-stage YAG laser or the like, and an optical origin initial adjusting method. It is about.

[0002]

2. Description of the Related Art Some laser devices using a multi-stage YAG laser have a resonator and an amplifier arranged in parallel.
In this case, the axis of the optical element such as the YAG rod needs to be accurately adjusted so as to coincide with the optical axis of the laser beam. For this reason, the following various means have conventionally been taken for adjusting the axis of an optical element such as a YAG rod.

FIG. 5 shows an example of a device used for adjusting the axis of an optical element such as a YAG rod when a resonator and an amplifier in a laser device are arranged in parallel. In the figure, reference numeral 1 denotes a laser oscillation device with a collimator that oscillates linearly polarized light He-Ne, which is visible light, as a reference laser beam 2, and 3 reflects the reference laser beam 2 output from the laser oscillation device 1. The reflecting mirror 4 changes the direction by 90 degrees, and the reflecting mirror 4 changes the direction by 90 degrees by further reflecting the reference laser beam 2 which has been reflected and reflected by the reflecting mirror 3 and changed in direction.

[0005] Further, reference numeral 5 denotes a resonator of the laser device which needs to adjust the optical axis, and 6 denotes a reference laser beam 2 sent from the resonator 5.
Is a reflecting mirror that changes the direction by 90 degrees, 7 is a reflecting mirror that changes the direction by reflecting the direction of the reference laser beam 2 reflected by the reflecting mirror 6, and changes the direction by 90 degrees. An amplifier for a laser device, which is disposed in parallel with the resonator 5 and requires adjustment of the optical axis;
Each of the folding mirrors 3, 4, 6, and 7 can rotate in a direction parallel to the plane of FIG. 5 for fine adjustment of the position.

The resonator 5 includes, for example, an optical surface plate 9, a base 10, which has been processed on the optical surface plate 9 with high precision in dimensions and horizontality, and an entrance of the base 10 in the reference laser beam 2 traveling direction. A pair of laser mirrors 11 and 12 for resonance amplification arranged on the upper surface of the side end and the outlet side;
A plurality of cavities 14 which are sequentially linearly arranged on the upper surface of the base 10 in the direction of travel of the reference laser beam 2 and in which the YAG rod 13 is positioned and accommodated, Each of the cavities 14 is provided at the entrance side of the reference laser beam 2 and has a thin plate-shaped aperture 16 in the center of which a pinhole 15 such as a pinhole through which the reference laser beam 2 can pass is provided (FIG. 6, FIG. 6). 7).

Although the amplifier 8 does not have the laser mirrors 11 and 12 like the resonator 5, the laser mirror 1
Except for the portions 1 and 12, the configuration is the same as that of the resonator 5.

A predetermined cavity 14 and a predetermined aperture 16 forming a pair with the cavity 14 are integrally assembled, and the center of the optical element such as the YAG rod 13 in the predetermined cavity 14 is This YAG
The axis of the pinhole 15 in the aperture 16 forming a pair with the rod 13 is set before the base 10 is set.
Position adjustment is performed in advance so as to match each other, and the cavity 14 and the aperture 16 can be adjusted in the X-Y biaxial directions while being set on the base 10 (here, X is the height direction, and Y is the radial direction of the YAG rod 13 in a plan view, that is, the horizontal direction).

In FIG. 6, reference numeral 17 denotes a rod holder provided in the cavity 14, and 18 denotes an inner periphery of the rod holder 17 and YA.
The optical element which is an O-ring interposed between the outer periphery of the G rod 13 and the optical axis of the resonator 5 and the amplifier 8 which needs to be adjusted for the axis is not limited to the YAG rod 13 but may be a lens or a lens (not shown). There are optical fibers and the like.

The resonator 5 and the amplifier 8 of the laser device described above.
The operation procedure for adjusting the axis of the optical element such as the YAG rod 13 so as to coincide with the optical axis of the reference laser beam 2 is performed as described below, for example. That is,
The optical elements such as the YAG rod 13 and the pinholes 15 of the aperture 16 in each cavity 14 are adjusted in advance so that their axes coincide with each other. In the case of the resonator 5, the position is adjusted together with the laser mirrors 11 and 12 and the amplifier. In the case of 8, the resonator 5 and the amplifier 8 are configured on the base 10 mounted on the optical surface plate 9 without the laser mirrors 11 and 12. Thus, the resonator 5 and the amplifier 8 are arranged substantially in parallel at a predetermined position such that the horizontal interval is a predetermined interval.

Next, a reference laser beam 2 serving as a reference optical axis is output from the laser oscillation device 1, and the traveling direction of the reference laser beam 2 is adjusted by adjusting the angles of the folding mirrors 3, 4, 6, and 7. Then, the cavity 14 and the aperture 16 are finely adjusted and moved integrally in the X-Y biaxial directions for each set,
Adjustment is made so that the reference laser beam 2 passes through the pinhole 15 of the aperture 16.

The reference laser beam 2 is applied to all apertures 16
, The axis of the optical element such as the YAG rod 13 coincides with the optical axis of the reference laser beam 2, and the position of the axis of the optical element with respect to the optical axis of the reference laser beam 2 is adjusted. Ends. Whether the axis of the optical element such as the YAG rod 13 coincides with the optical axis of the reference laser beam 2 depends on whether the reference laser beam 2 is in the pinhole 1 of the aperture 16.
5 is visually determined by an operator as to whether or not the vehicle has passed 5 in a predetermined state.

The YAG in the resonator 5 and the amplifier 8
As another means for adjusting the axis of the optical element such as the rod 13 so as to be coincident with the optical axis of the reference laser beam 2, the aperture 16 shown in FIGS. The dimensions, horizontality, and verticality of other structural parts are manufactured with high precision, and the base 10 and the structural parts are assembled so that the positional relationship between them is maintained with high precision. In some cases, the two optical axes are made to coincide.

Further, as another means for making the axis of the optical element coincide with the optical axis of the laser beam, see Japanese Patent Application Laid-Open No. 10-20950.
As disclosed in Japanese Patent Laid-Open No. 2 (1999) -1995, there is also a device in which the position of the center of gravity of a beam is detected using an infrared camera or an image processing device.

However, as shown in FIG. 5, when the axis of an optical element such as a YAG rod is aligned with the optical axis of the reference laser beam 2 using the pinhole 15,
If the diameter of the reference numeral 5 is small, the reference laser beam 2 does not pass through the pinhole 15, so that the position of the axis may not be adjusted. Since it is necessary for an operator to visually determine whether or not the light 2 coincides with the optical axis, it is difficult to obtain high adjustment accuracy.

In the case where the base 10 and the structural components are assembled so that the positional relationship between them is maintained with high accuracy, the axis of the optical element and the optical axis of the reference laser beam 2 are aligned. Since the accuracy depends on the mechanical accuracy, when the object whose axial center is to be aligned with the optical axis of the reference laser beam 2 is large and heavy, the deformation cannot be avoided. As in the case, high accuracy cannot be obtained, and furthermore, since the position of the optical axis is determined indirectly, a large error occurs compared to the case of directly determining the position as in FIG. easy.

Further, as disclosed in Japanese Patent Application Laid-Open No. 10-209502, in the case of using an infrared camera or an image processing device, there is a problem that the device becomes complicated and the price becomes high.

[0017]

In order to solve the above-mentioned problems, the present applicant has proposed an apparatus for adjusting the axial center of an optical element as disclosed in Japanese Patent Application Laid-Open No. H11-186310.
In other words, the apparatus for adjusting the axis of the optical element includes equipment shown in FIG. 8 in addition to equipment common to the apparatus shown in FIG. That is, the resonator 5 includes the laser mirror 11,
Optical axis positioning jigs 18 and 19 are provided on the optical surface plate 9 so as to be located at the entrance end and the exit end of the reference laser beam 2 with respect to the reference laser beam 2. The optical axis positioning jigs 18 and 19 are fixed on the optical surface plate 9 so as to be located at the entrance side end and the exit side end of the optical disk 2. The optical axis positioning jigs 18 and 19 are provided with the resonator 5
And for positioning the reference laser beam 2 when the axis of the optical element such as the YAG rod 13 in the amplifier 8 is aligned with the optical axis of the reference laser beam 2.
A small hole 20 of about 2 mm that can pass through is formed.

In the resonator 5 and the amplifier 8, a jig provided on the entrance side of each cavity 14 in which an optical element such as a YAG rod 13 is housed is replaced with an optical element such as a YAG rod instead of the aperture 16 in FIG. Is the reference laser beam 2
A position detector 21 for detecting whether or not the optical axis coincides with the optical axis is provided. The cavities 14 accommodating the optical elements such as the YAG rod 13 and the position detector 21 paired with the cavities 14 are integrally adjusted in the XY directions while being set on the base 10. I am getting it.

The position detector 21 is called a PSD position detector, and an example of the cross-sectional shape is shown in FIG. In other words, the position detector 21 is composed of three layers, a P layer 22 on the front surface of a flat silicon plate, an N layer 23 on the back surface, and an I layer 24 in the middle, and is incident on the light receiving surface of the position detector 21. The light is photoelectrically converted and the light currents I1 and I2
Are output separately from the electrodes 25 and 26 connected to the P layer 22.

Further, if the values of the photocurrents I1 and I2 are known, the light oscillated from the laser oscillation device 1 and incident on the position detector 21 is moved with respect to the origin (optical origin) (0, 0) of the position detector 21. It is possible to detect how far it has shifted. Thus, when the incident light passes through the origin (0, 0) of the position detector 21, the detection output of the photocurrent becomes zero. In this case, the optical origin of the position detector 21 is This is the state with the highest accuracy that matches the optical axis.

In FIG. 8, the same components as those shown in FIG. 5 are denoted by the same reference numerals.

In the above-described apparatus for adjusting the axis of the optical element,
When adjusting the axis of the YAG rod 13 in the resonator 5 and the amplifier 8 so as to coincide with the optical axis of the reference laser beam 2, first, an initial adjustment is performed so that the optical origin of the position detector 21 is aligned with the center of the machine. Need to do.

For this reason, in the above-mentioned apparatus for adjusting the axis of the optical element, first, the X-rays are provided on the entrance side and the exit side of the resonator 5 and the optical base 9 of the amplifier 8 in the traveling direction of the reference laser beam 2.
Optical axis positioning jigs 18, 19 with accurate Y-direction accuracy
Is installed.

On the other hand, the cavity 14 in which the YAG rod 13 is accommodated and the position detector 21 attached to the jig provided in the cavity 14 are mechanically mounted on the optical element such as the YAG rod 13 before being attached to the base 10. The position is adjusted in advance so that the axis and the mechanical axis of the position detector 21 substantially match, and the mechanical axis of the position detector 21 is positioned with respect to the mechanical center of the jig. It is matched. In this case, the optical origin (0, 0) of the position detector 21 does not always coincide with the mechanical axis of the optical element.

The cavity 14 in which the YAG rod 13 is accommodated and the position detector 21 attached to the jig provided in the cavity 14 are provided together with the laser mirrors 11 and 12 in the case of the resonator 5 and the amplifier 8. In the case of (1), the laser mirrors 11 and 12 are not provided, and the laser mirrors 11 and 12 are placed at a predetermined position on a base 10 mounted on an optical surface plate 9. 5 and the amplifier 8 are assembled. In this case, the resonator 5 and the amplifier 8 are arranged at predetermined positions such that the mechanical axes are substantially parallel and the interval in the left-right direction is a predetermined interval.

In the initial adjustment of the optical origin of the position detector 21, the reference laser beam 2 is output from the laser oscillation device 1 and the angles of the folding mirrors 3, 4, 6, 7 are adjusted to adjust the reference laser beam 2. Is adjusted so as to pass through the small holes 20 of the optical axis positioning jigs 18 and 19, and the reference laser beam 2 is sent to the resonator 5 and the position detector 21 of the amplifier 8, and passes through the position detector 21. Therefore, photocurrents I1 and I2 having different values are output from the electrodes 25 and 26 of the position detector 21 in accordance with the deviation between the optical axis of the position detector 21 and the optical axis of the reference laser beam 2. Is done.

For this reason, the worker, for example, needs to
Photocurrents I1 and I2 output from the first electrodes 25 and 26
Is adjusted by slightly moving each position detector 21 in the XY directions so that is zero. When the position detector 21 is slightly moved, the set screw of the jig on which the position detector 21 is set is loosened, and the position detector 21 is rotated in the circumferential direction. When the position adjustment of the position detector 21 is completed, the position detector 21 is fixed to the set jig again by the set screw.

If the difference between the photocurrents I1 and I2 output from the electrodes 25 and 26 of the position detector 21 becomes zero as a result of the position adjustment of the position detector 21 in the X and Y directions, the resonator 5 and the amplifier 8 It was determined that the optical origin of the position detector 21 in the above was coincident with the optical axis of the reference laser beam 2, and the optical origin of the position detector 21 was aligned with the machine center of the jig provided in the cavity 14. It will be.

According to such an optical element axial center adjusting apparatus,
By a simple and inexpensive means, the light of the reference laser beam 2 output from the laser oscillation device 1 is easily, accurately and quickly placed on the axis of an optical element such as the YAG rod 13 in the resonator 5 or the amplifier 8 of the laser device. The optical axis can be adjusted so that the axes coincide.

[0030]

However, Japanese Patent Application Laid-Open No.
In the device for adjusting the center of the optical element shown in the specification of Japanese Patent No. 186310, the reference laser beam 2 is located at the optical origin of the position detector 21.
Regarding the point of the initial adjustment of aligning the optical axes of the apertures, as shown in FIG.
Adjustment is more difficult than in the case where the optical axis of the reference laser beam 2 is aligned, and time is required. That is, when the reference laser beam 2 strikes the optical origin, the position output of the position detector 21 becomes zero, and the detection accuracy is the highest.

On the other hand, since the position of the optical origin of the position detector 21 is not mechanically accurate, the optical origin of the position detector 21 is attached to the position detector 21 as an initial adjustment. It is necessary to make adjustments to match the mechanical rotation center (axis) of the jig attached to the cavity 14. Thus, in order to match the optical origin of the position detector 21 with the mechanical rotation center (axis) of the jig, the position detector 21 is set on the jig, and then a micrometer or the like is used. The position of the position detector 21 with respect to the jig is finely adjusted, and thereafter, the position detector 21 is screwed to the jig.

However, in such an adjustment method, the position of the position detector 21 is slightly shifted by several μm at the time of screwing.
1 had to be fixed to the jig. However, several μ
It is very difficult to regulate the adjustment in m units by the degree of screw tightening. Also, if the optical origin of the position detector 21 does not match the mechanical rotation center (axis) of the jig after tightening. Is
There is a problem that it is necessary to loosen the screws and perform re-adjustment, and as a result, a large amount of time must be spent for initial adjustment. Also, considering the displacement due to screw tightening, the position detector 21 may not be fixed to the jig with a sufficient tightening torque, so that the mounting strength of the position detector 21 after the initial adjustment is low, and There is also a problem that is weak.

In view of the above-mentioned circumstances, the present invention can easily, accurately and quickly align the optical origin of the position detector constituted by the so-called PSD with the center of the jig machine (mechanical origin) in the initial adjustment. It is done for the purpose of doing so.

[0034]

An optical origin adjusting apparatus according to the present invention comprises a position detector which can detect a position of an optical origin with respect to a detection surface of irradiated reference laser light by a photocurrent by using a laser rod. It is set on a jig attached to the provided cavity, and a plurality of detection circuits each having a variable resistor are connected to the position detector.

In the method for initial adjustment of the optical origin according to the present invention, the resistance value of each detection circuit is adjusted by the variable resistor of the optical origin adjusting device, and the position of the optical origin relative to the detection surface of the irradiated reference laser light is determined. It is electrically adapted to the machine center.

According to the present invention, the adjustment of the optical origin of the position detector can be greatly simplified, and the accuracy of the optical origin of the position detector depends on the fixed state of the jig provided in the cavity. The position detector is firmly fixed to the jig, and there is no need to loosen and retighten the set screw once tightened, which is necessary for initial adjustment. The time can be greatly reduced and the optical origin of the position detector can be easily, accurately and quickly aligned with the center of the machine.

[0037]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the embodiment of the present invention. Although the basic configuration of the apparatus is not shown, it is the same as the apparatus shown in FIG. 8 is different from the apparatus of FIG. 8 in that the electrodes 25 and 26 of the position detector 21 set in a jig provided in the cavity 14 shown in FIG.
, A detection circuit 29 having variable resistors 27 and 28, respectively.
30 is connected so that the resistance values of the detection circuits 29 and 30 can be adjusted. In FIG. 1, reference numeral 31 denotes a detector.

In the case of FIG. 1, since only the deviation of the optical origin in the direction parallel to the paper surface, for example, the X direction, is detected, the direction orthogonal to the paper surface of FIG.
In order to detect the deviation of the optical origin in the direction, the electrodes as shown in FIG. 2 are required on the near side and the far side with respect to the paper surface of FIG. 2, and a variable resistor is provided and connected to each electrode. The required detection circuit is required.

Next, the operation of the embodiment of the present invention will be described with reference to FIGS.

In the illustrated example, the cavity 14 in which the YAG rod 13 is housed and the position detector 21 attached to the jig provided in the cavity 14 also include the base 10.
Before being mounted on the position detector 2, position adjustment is performed in advance so that the mechanical axis of the optical element such as the YAG rod 13 substantially coincides with the mechanical axis of the position detector 21.
One mechanical axis is aligned with the jig.

When the optical origin of the position detector 21 is initially adjusted, the reference laser beam 2 is output from the laser oscillation device 1 and the angles of the folding mirrors 3, 4, 6, and 7 are adjusted. Is adjusted so as to pass through the small holes 20 of the optical axis positioning jigs 18 and 19, and the reference laser beam 2 is sent to the resonator 5 and the position detector 21 of the amplifier 8 to irradiate the detection surface. Therefore, the position detector 2
The first electrodes 25 and 26 output photocurrents I1 and I2 having different values according to the deviation between the optical origin of the position detector 21 and the optical axis of the reference laser beam 2.

For this reason, the worker operates the detection circuits 29, 3 in each position detector 21 so that the photocurrents I1, I2 outputted from the electrodes 25, 26 of each position detector 21 become zero.
The zero variable resistors 27 and 28 are adjusted. Thus, if the resistance values of the system of the detection circuit 29 and the system of the detection circuit 30 including the resistance values set by the variable resistors 27 and 28 and the internal resistance of the position detector 21 become equal, the position detector 2
The values of the photocurrents I1 and I2 output from 1 become zero,
The position where the reference laser beam 2 contacts the detection surface of the position detector 21 is the optical origin. Therefore, the optical origin of the position detector 21 is electrically aligned with the mechanical center (origin) of the jig.

In the initial adjustment of the optical origin of the position detector 21, the position detector 21 is firmly fixed to a jig attached to the cavity 14 with a set screw. There is no loosening.

For example, when the variable resistors 27 and 28 are not provided in the detection circuits 29 and 30, the optical origin X1 on the detection surface of the position detector 21 is the position of the jig attached to the cavity 14, as shown in FIG. If it is far from the point of the machine center X2, it is necessary to loosen the set screw and finely mechanically adjust the position detector 21 from the position of the imaginary line in FIG. 4 to the position of the solid line to align the optical origin X1 with the machine center X2. As a result, the above-described problem has occurred. However, in the case of the illustrated example, by adjusting the variable resistors 27 and 28, FIG.
As shown in (1), the optical origin X1 can be electrically adjusted to the mechanical center X2.

Therefore, the position detector 21 does not shift due to the tightening of the jig by the set screw.
In the initial adjustment of the optical origin, there is no uncertainty that the accuracy depends on the fixing state of the jig. As a result, the adjustment time of the optical origin can be greatly simplified. Further, there is no uncertain factor that the accuracy is affected by the fixing state of the jig.
1 can be firmly fixed to the jig. In addition, since there is no need for a return work of loosening and retightening the set screw once tightened, the time required for the initial adjustment can be greatly reduced.

It should be noted that the present invention is not limited to only the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0048]

According to the optical origin adjusting device and the optical origin initial adjusting method of the present invention, it is possible to greatly simplify the adjustment of the optical origin of the position detector and to fix the optical origin in the cavity. There is no uncertainty that the accuracy of the optical origin depends on the fixing state of the jig, so that the position detector can be firmly fixed to the jig.
Since there is no need to re-tighten the set screw once again, the time required for initial adjustment can be greatly reduced, and the optical origin of the position detector can be easily, accurately and quickly adjusted to the center of the machine. And various other excellent effects can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a position detector including a detection circuit, showing an outline of an example of an embodiment of the present invention.

FIG. 2 is a front view of the position detector illustrating a state in which an optical origin of the position detector is electrically initially adjusted.

FIG. 3 is a front view of the position detector for explaining a state in a case where the optical origin of the position detector is mechanically initially adjusted, and is a front view showing a state before the initial adjustment.

FIG. 4 is a front view of the position detector illustrating a state in which the optical origin of the position detector is mechanically initially adjusted, and is a front view showing a state after the initial adjustment.

FIG. 5 is a layout diagram showing an example of an outline of a conventional device.

FIG. 6 is a sectional view of a cavity applied to the apparatus of FIG. 5;

FIG. 7 is a front view of an aperture applied to the apparatus of FIG. 5;

FIG. 8 is a layout view showing an outline of a device obtained by improving the device shown in FIG.

FIG. 9 is a schematic sectional view of a position detector applied to the apparatus of FIG.

[Explanation of symbols]

 2 Reference laser beam 13 YAG rod (laser rod) 14 Cavity 21 Position detector 27 Variable resistor 28 Variable resistor 29 Detection circuit 30 Detection circuit X1 Optical origin

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Minoru Uehara 3-1-1, Toyosu, Koto-ku, Tokyo Ishikawajima-Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Fumio Matsuzaka 3-1-1, Toyosu, Koto-ku, Tokyo No. 15 Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Takeshi Arai 9-18-1-401 Onakadai, Inage-ku, Chiba Chiba Prefecture 5F049 NA18 NB07 RA02 UA01 UA04 5F072 AB01 AK01 JJ20 KK05 KK30 MM08

Claims (2)

[Claims] 1. A position detector which is capable of detecting the position of an optical origin with respect to a detection surface of an irradiated reference laser beam by a photocurrent is set on a jig attached to a cavity provided with a laser rod, and the position is determined. An optical origin adjusting device, wherein a plurality of detection circuits each having a variable resistor are connected to the detector. 2. A variable resistor according to claim 1, wherein the resistance value of each detection circuit is adjusted so that the position of the optical origin with respect to the detection surface of the irradiated reference laser light is electrically adjusted to the mechanical center. The initial adjustment method of the optical origin which is the feature.