JP2552615B2 - Laser cavity alignment holding device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a high speed automatic scanner,
Material processing, surgery, a laser lasers co exciter alignment holding device used in various fields such as laser communications.

[0002]

2. Description of the Related Art Generally, a laser operates in the infrared / visible / ultraviolet region based on the principle that electromagnetic waves are amplified by stimulated emission.
There is an amplification medium, a pump output source, and a resonator. The resonator repeats the light on the optical axis between the mirrors at both ends, stays in it for a long time, and grows into strong oscillation.
When one of the mirrors is made slightly transparent, a part of the amplified radiation light (laser beam) is extracted to the outside. This laser beam can extract various wavelengths depending on the amplification medium and the distance between the mirrors.
When extracting a laser beam of a desired wavelength, it is desired that there is no mirror distance or optical axis deviation. Therefore, a laser cavity alignment holding device is required.

7 and 8 show a conventional resonator alignment holding device. This resonator alignment holding device holds mirror holders 103 and 104 respectively holding a pair of mirrors 101 and 102 facing each other at a plurality of positions using holding rods 105 made of Invar having a low coefficient of thermal expansion, and is high in an amplification medium. The distance between the mirrors is prevented from fluctuating even with a heat load caused by energy.
Then, in order to adjust the oscillating beam 108 (shown by hatching in the figure) to a desired oscillating position, at least three beam sensors 107 (temperature sensors) for detecting the beam position are attached in a direction perpendicular to the optical axis 109, When the beam hits the sensor 107, the temperature of the sensor 107 rises, and the mirror position is adjusted so that the beam does not hit the sensor 107. In the figure, the state A shows the case where the oscillation beam 108 hits one of the beam sensors 107, and the state B shows the case where the beam does not hit the sensor 107 after adjustment.

[0004]

However, as shown in FIG.
In the alignment holding device shown in FIG. 8, it is not possible to hold the mirrors at a desired distance due to mechanical vibration transmitted to the alignment holding device and aging of the holding rod 105 made of a material having a low coefficient of thermal expansion. Further, when the optical axis shift occurs due to the mechanical vibration or the like, it is necessary to stop the laser oscillation once and then manually adjust the mirror. That is, the laser oscillation position with respect to the mirror can be adjusted at the initial stage, but it cannot be corrected during continuous oscillation, and the displacement of the distance between the mirrors due to the thermal load that occurs during that period and the in-plane displacement of the mirror over time are handled. However, there is a problem that the beam mode cannot always be maintained accurately. Moreover, since the beam sensor is a temperature sensor, the accuracy of its information is poor, and there is a problem in that it cannot be held with high accuracy.

The object of the present invention is to prevent mechanical vibration and secular change .
Even more displacement or the like of the inter-mirror distance and the optical axis is formed which normally
When detected with high accuracy, it is to provide a <br/> lasers co exciter alignment holding device can be corrected in the laser cavity operation.

[0006]

Means for Solving the Problems] lasers co exciter alignment holding device according to claim 1, opposite of the laser resonator 1
One of the pair of mirrors to the laser beam
In-plane displacement adjustment mechanism for adjusting and displacing in the direction perpendicular to
The mirror of the other mirror is immovable relative to the mirror
The laser beam from one side to one of the mirrors.
The projector and one of the mirrors are fixed so that they cannot move relative to each other.
Multiple lasers, each receiving laser light from several projectors
An in- plane displacement detecting means including an interferometer for detecting in- plane displacement of one mirror in a direction perpendicular to the laser beam, and in-plane displacement adjustment based on a detection signal from the in-plane displacement detecting means and an initial setting value. And a control device for outputting a drive control signal to the mechanism.

Holding the laser cavity alignment according to claim 2.
Device is the invention of claim 1, wherein the plane displacement adjustment mechanism, which is formed one of the mirrors between the outer peripheral portion of the holder and one of the mirrors displaceably held in its plane direction
A plurality of pressure chambers, a liquid filled in these pressure chambers,
Wherein a to shall and characterized by comprising an actuator for displacing the plane of one of the mirrors by varying the pressure of the sealed liquid based on a signal from the controller.

[0008] lasers co exciter alignment holding device according to claim 3 is the invention of claim 1 or claim 2, wherein the 1
A distance displacement adjustment mechanism that adjusts the distance between the pair of mirrors ,
It is provided so that it cannot move relative to the other mirror.
Project laser light from one mirror side to one mirror side
Multiple light projectors and one of the mirrors are fixed so that they cannot move relative to each other.
A plurality of laser beams emitted from a plurality of projectors, respectively.
The laser interferometer of
And a distance displacement detecting means for detecting, the control device,
Based on the detection signal from the distance displacement detection means and the initial setting value
It is characterized in that for outputting a drive control signal to the distance displacement adjustment mechanism Te.

Holding the laser cavity alignment according to claim 4.
Device is the invention of claim 3, wherein the distance displacement adjusting mechanism includes a pressure chamber formed between the displaceably held sulfo Ruda and one Mirror said one mirror in the optical axis direction , further comprising a sealed liquid sealed in the pressure chamber, and an actuator for displacing the optical axis direction one of Mi <br/> error by varying the pressure of the sealed liquid based on a signal from the control device It is characterized by .

[0010] lasers co exciter alignment holding device according to claim 5, among the pair of mirrors facing the laser resonator
A mirror curvature adjusting mechanism for displacing the curvature of one of the mirrors , a laser light projector, and a reference for the one mirror.
The reference mirror and one of the mirrors projected from the laser beam projector.
The laser light reflected by the mirror and the reference mirror
Laser including a light receiving element that receives light
And <br/> mirror curvature displacement detecting means for detecting a curvature displacement of one mirror through the interference fringes of light, one of the mirror curvature adjustment mechanism based on the detection signal from the mirror curvature displacement detecting means
And a control device that outputs a control signal for matching the curvature of the mirror with the curvature of the reference mirror .

Holding the laser resonator alignment according to claim 6.
Device is the invention of claim 5, wherein one mirror is made of an elastic membrane, the curvature adjustment mechanism, one of the mirror and the pressure chamber formed between the holder and sealed in the pressure chamber those characterized with sealed liquid, further comprising an actuator for displacing the curvature of one of the mirrors by varying the pressure of the sealed liquid based on a signal from the control device
It is.

[0012]

According to the first aspect of the invention, the relative positions of the pair of mirrors facing each other can be gradually displaced in the resonator due to the thermal load or mechanical vibration in accordance with the oscillation of the laser. There is a nature. For example, when the position of the mirror is displaced in the direction perpendicular to the optical axis, the output wave having a desired wavelength cannot be extracted due to the displacement of the optical axis. Therefore, phase and against the other mirror
One mirror is installed immovably from the other mirror side
Multiple projectors that project laser light toward the
It provided relatively immovable in the error record from a plurality of light emitting devices
Laser interferometers for receiving laser light, respectively.
The in-plane displacement of one mirror in the direction perpendicular to the laser beam
In-plane displacement detection means is provided, and this in-plane displacement detection means
The in-plane displacement of one mirror in the direction perpendicular to the laser beam.
Then, this is compared with an initial set value stored in advance in the control device, and if it is moving from the initial state, a correction signal is output to the in-plane displacement adjusting mechanism so as to match the initial set value. The plane displacement adjustment mechanism, one based on the correction signal
The square mirror is moved in a direction perpendicular to the optical axis, to correct the in-plane displacement.

Thus, one of the mirrors with respect to the other
Detects even if the relative position of the mirror is displaced in the in-plane direction
Drive control of the in-plane displacement adjustment mechanism compared to the initial state.
To adjust the relative position of both mirrors to the initial state
The alignment of the relative position of the pair of mirrors in the in-plane direction
Can be held. Moreover, in-plane displacement detection means
Does not move relative to the other mirror and projects laser light .
Multiple projectors that shine and one that cannot move relative to the other
Using multiple laser interferometers and using laser light
Therefore, the beam sensor using the temperature sensor shown in FIG.
It is possible to obtain accurate and highly accurate information compared to a sensor.
Can .

According to the second aspect of the present invention , the heat load of the mirror of the laser resonator usually increases greatly, and it is necessary to cool the mirror. Therefore, the in-plane displacement adjustment mechanism holds one mirror so that it can be displaced in the in-plane direction.
Between the holder and the outer circumference of one of the mirrors.
Multiple pressure chambers and the fill liquid enclosed in these pressure chambers
And the pressure of the filled liquid is changed based on the signal from the controller.
Actuator that moves to move one mirror in-plane
Since the configuration with bets can Rukoto displaces a plane mirror by utilizing pressure fluctuations sealed liquid of a plurality of pressure chambers
It In addition, the same operation as in claim 1 is achieved.

In the third aspect of the invention, since the desired output wave cannot be extracted when the distance between the mirrors changes,
It is provided so that it cannot move relative to the other mirror
A compound that projects laser light from one side of the mirror to the other.
A number of floodlights and one mirror are immovably mounted
Multiple lasers that respectively receive the laser beams from the multiple projectors.
Laser interferometer to detect displacement of the distance between the mirrors
The distance displacement detecting means is provided, and this distance displacement detecting means
The distance between the mirrors is measured, the measured value is compared with the initial setting value, and the distance displacement adjusting mechanism is controlled to correct the distance.

Thus, the distance between the pair of mirrors is displaced.
Even if this is detected and compared with the initial state, the distance displacement adjustment
Drives the alignment mechanism to set the distance between both mirrors to the initial state
So that the distance between the pair of mirrors is aligned
Can be held. Moreover, the distance displacement detecting means is
Projects a laser beam that cannot move relative to the other mirror
Multiple projectors, and multiple projectors that cannot move relative to one
Equipped with a laser interferometer of
Therefore, the beam sensor using the temperature sensor shown in FIG.
Can obtain accurate and highly accurate information compared to
It Other functions similar to those of claim 1 or claim 2 are achieved.
It

In the fourth aspect of the invention, the mirror of the resonator usually needs to be cooled because its thermal load causes a large temperature rise. Therefore, the distance displacement adjustment mechanism, the one mirror and the pressure chamber formed between the optical axis direction to movably hold <br/> sulfo Ruda and one Mirror, to the pressure chamber a sealed liquid sealed, since a structure in which an actuator for displacing the optical axis direction one of the mirror <br/> over by varying the pressure of the sealed liquid based on a signal from the control device, the pressure can Rukoto displaces the mirror in the optical axis direction by utilizing the pressure fluctuations in the chamber of the sealed liquid. Other requests
The same operation as item 3 is achieved.

In the fifth aspect of the invention, generally, in the total reflection mirror, a part of the strong light of the oscillating laser is absorbed inside the laser resonator, so that the shape changes due to the heat load. For this reason, the back surface of the total reflection mirror is cooled, but thermal distortion occurs due to the temperature difference caused by this,
A shift in a direction orthogonal to the optical axis and a change in curvature occur in addition to the distance between the mirrors in the optical axis direction. If this curvature changes, the output of the desired wavelength cannot be obtained as in the case of in-plane displacement and distance displacement. Therefore, laser light projector
And a reference mirror to be used as a reference for the one mirror,
And one mirror and the reference mirror projected from the laser projector
And a light receiving element that receives the laser light reflected by the
Through the interference fringes of the laser light received by the light receiving element
Mirror curvature displacement detection that detects the curvature displacement of one mirror
Means is provided, and by this mirror curvature displacement detection means,
The change in the shape of the mirror of is detected using laser light,
Control the curvature adjustment mechanism by the controller based on the detection signal
The curvature of one mirror to the curvature of the reference mirror.
Let

In the invention of claim 6, the one of the
Is composed of an elastic film, the curvature adjusting mechanism is
The pressure chamber formed between the
Filling liquid filled in the pressure chamber and a signal from the control device
The pressure of the filled liquid is changed based on the
With an actuator for displacing
The curvature of the mirror by using the pressure fluctuation of the filled liquid in the pressure chamber.
Can be changed. Other products similar to claim 5
Play a role .

[0020]

EXAMPLES diagram of lasers co exciter alignment holding device according to a first embodiment of a First Embodiment FIG. 1 according to the present invention, FIG. 2 is likewise a surface view of the first mirror, Figure 3 is also a FIG. 4 is a back view of the first mirror, and FIG. 4 is a back view of the second mirror.

As shown in FIG. 1, the laser of this embodiment has an amplification medium 1 and a pump output source 2 as its main constituent elements.
, Laser resonator 3, and resonator alignment holding device 4
Have and . The amplification medium 1 may be a gas such as carbon dioxide, nitrogen, or helium, or a solid such as a semiconductor. However, in the present embodiment, generally carbon dioxide capable of continuous oscillation is used. The pump output source 2 causes a large current to flow through the amplification medium 1, whereby the distribution of each energy level is largely shifted from the thermal equilibrium state and the number of atoms in the excited state is accumulated. That is, the laser of this embodiment is a gas discharge laser.

The laser resonator 3 comprises a first mirror 5 and a second mirror 6 arranged at both ends of the amplification medium 1, and holders 7 and 8 respectively supporting these.
The first mirror 5 is, for example, a total reflection mirror in which a copper plate is plated with gold or the like, and is formed in a concave surface to reduce optical loss. A first holder 7 that supports this first mirror 5.
As shown in FIGS. 2 and 3, it is formed in a disk shape, to
The first mirror 5 is Ru Tei fixed. The second mirror 6 is a planar semi-transmissive mirror formed of a crystal plate such as zinc selenium or gallium arsenide, and is capable of extracting a part of the radiated light amplified in the resonator 3 to the outside. Has been done. The second holder 8 for supporting the second mirror 6, shown in Figure 4
Suyo is formed in a disc shape, the through-holes 8a to take out the output light at the center is formed. Of these holders 7 and 8,
The second holder 8, since the second mirror 6 is not required to adjust the deviation of the plane mirror der because the optical axis, is fixed to the holding device body 9. On the other hand, in the first holder 7, since the first mirror 5 is a concave mirror, the optical axis may shift.
Since, in the holding apparatus main body 9, it is adjustably held with respect to the optical axis 11 of the laser 10 to the perpendicular direction and the optical axis direction Tei
It

The laser cavity alignment holding device 4 is
A plane displacement adjustment mechanism 13 for adjusting displaced perpendicularly to the optical axis 11 of the laser beam 10 a first mirror 5, first
A laser beam perpendicular plane displacement of the mirror 5 and the plane displacement detecting sensor 14 for measuring using light, a distance displacement adjustment mechanism 15 for adjusting displacement of the spacing of the opposing mirrors 5 and 6, mirror The distance displacement detection sensor 16 for measuring the distance between 5 and 6 using light and the output signal from the in- plane displacement detection sensor 14 are compared with an initial set value, and the in-plane displacement is calculated based on the calculation result. outputs a drive control signal to the adjustment mechanism 13, a control for outputting a drive control signal to the distance displacement adjustment mechanism 15 based on the output signal to an initial set value is compared with the calculation result from the distance displacement detecting sensor 16 And a device 18.

[0024] The plane displacement adjustment mechanism 13 in FIG. 1-3
As shown , the outer periphery of the first holder 7 and the holding device body 9
It is a solid-state element actuator having a well-known structure which is interposed at three positions between and, and includes, for example, a coarse movement section and a fine movement section using a micro servo technique such as a giant magnetostrictive element, a piezoelectric element, a ball screw, and a stepping motor. As shown in FIGS. 1 and 3 , the distance displacement adjusting mechanism 15 is interposed at three positions between the back surface of the first holder 7 and the holding device body 9, and the in-plane displacement adjusting mechanism 13 is provided. It has the same structure as. As shown in FIG. 4 , the in- plane displacement detection sensor 14 includes a second holder 8
As shown in FIG. 2 , a light emitting section 20 using a laser installed at three locations on the outer periphery of the
To, Ru Tei is composed of a laser interferometer as a light receiving unit 21 installed on the outer periphery of the first holder 7.

[0025] The distance displacement detecting sensor 16, as shown in FIG. 4, a light emitting unit 22 using the installed laser at three positions on the outer peripheral portion of the second holder 8, to face the light emitting unit 22, FIG. 2 As shown in , a laser interferometer as a light receiving portion 23 is provided on the outer peripheral portion of the first holder 7. Positional relationship between the light emitting portion 20 and the distance displacement measurement of the light emitting portion 22 of the plane for displacement measurement, as shown in FIG. 4, are arranged with a 60 ° phase difference from each other. Then, the laser interferometers as the light receiving units 21 and 23 compare the interference fringes measured at the beginning with the interference fringes after the displacement, and based on this, detect whether or not the displacement has occurred.

The control device 18 for this purpose is shown in FIG .
As described above , the microcomputer is configured to input the interference fringe signal from the in-plane displacement detection sensor 14 and the distance displacement detection sensor 16 and compare the interference fringe signal with an initially measured interference fringe signal . It outputs to the inner displacement adjusting mechanism 13 and the distance displacement adjusting mechanism 15. Therefore , the control device 18 has means for storing the mode of the initial interference fringes, means for comparing the currently measured interference fringes with the stored initial interference fringes, and feedback to the adjusting mechanism based on the comparison result. Adjustment mechanism control means for outputting a signal is provided for each of the in-plane displacement correction and the distance displacement correction.

[0027] In the above configuration, at the time of laser oscillation,
First, the alignment adjustment of the mirrors 5 and 6 is performed. At this time, the laser 24 is emitted from the light emitting unit 20 of the in-plane displacement detection sensor 14, and the light receiving unit 21 receives the laser 24 to detect interference fringes at a total of three places. This is stored in the control device 18. Similarly, the laser 24 is also emitted from the light emitting portion 22 of the distance displacement detection sensor 16, and the light receiving portion 23 receives the laser 24, and the interference fringes from a total of three locations are stored. This is the initial setting state, and if an in-plane displacement and a distance displacement occur thereafter, feedback control is performed so as to eliminate them. That is, there is a possibility that the positions of the mirrors 5 and 6 will be gradually displaced in the resonator 3 due to the heat load or mechanical vibration due to the oscillation of the laser. For example, when the mirrors 5 and 6 are displaced in the direction perpendicular to the optical axis 11, the output wave having a desired wavelength cannot be extracted due to the optical axis deviation.

Therefore, the in-plane displacement is detected by the in-plane displacement detection sensor 1.
4, the interference fringes are detected from the light receiving section 21 on the first mirror side. This is compared with the initial interference fringes stored in advance in the controller 18, and if the interference fringes are moving from the initial state, a correction signal is sent to the in-plane displacement adjusting mechanism 13 so as to match the initial interference fringes. Output. In-plane displacement adjustment mechanism 13 to move the first holder 7 on the basis of the control signal in a direction perpendicular to the optical axis, to correct the in-plane displacement. Similarly, a desired output wave cannot be extracted even if the distance between the mirrors 5 and 6 changes, so the distance is detected by the distance displacement detection sensor 16,
The distance displacement adjusting mechanism 1 compares the interference fringes with the initial interference fringes.
5 is controlled to correct the distance.

As described above, the in-plane displacement detection sensor 14 and the distance displacement detection sensor 16 measure the initial position and distance of the mirrors, and then the positions of the mirrors 5 and 6 are affected by thermal load and mechanical vibration during continuous oscillation. And the distance are displaced, the in-plane displacement detection sensor 14 and the distance displacement detection sensor 16 measure the measured values and compare them with the initial state, and the mirror adjustment mechanisms 13 and 15 are feedback-controlled. Can always get Moreover, the in-plane displacement detection sensor 14 and the distance displacement detection sensor 16 are
Since the sensor uses light, more accurate and highly accurate information can be obtained as compared with the beam sensor using the temperature sensor shown in FIG.

As a means for measuring the displacement of the in-plane position or distance by using light, a method of utilizing the light of the laser oscillator itself and detecting the relative change amount of the mirror transmitted light and the mirror reflected light is also considered. However, in this case, the concave mirror has to be a semi-transmissive mirror, which causes a problem that the amplification factor of the resonator is reduced. However, in this embodiment, the displacement of the displacement is detected by using the light of the laser oscillator itself. Rather than doing so, separate light emitting parts 20, 22 installed in the holders 7, 8
Since the detection is performed using the light receiving units 21 and 23, the displacement can be detected without affecting the amplification factor of the resonator 3 and the like.

[Second Embodiment] FIG. 5 is a block diagram of a laser resonator alignment holding device according to a second embodiment of the present invention. Usually, the mirrors 5 and 6 of the laser resonator 3 have to be cooled because their heat loads greatly increase in temperature. In order to cope with this, the present embodiment is a modification of the structures of the in-plane displacement adjusting mechanism 13 A and the distance displacement adjusting mechanism 15 A with respect to the first embodiment.

That is, the first holder 7 is fixed to the holding device main body 9, and the concave portion 26 for fitting the first mirror is formed inside the first holder 7. The first mirror 5 is fixed the rear surface thereof is a thin elastic plate 27, Ru this sheet 27 Gaho Ruda 7 freely optical axis direction movement in the recess 26 of and fitted movably and perpendicularly the optical axis 10 Empire. The cooling pipe 29 in thin plate 27 and the recess wall and the pressure chamber 28 formed in the holder 7 is inserted, also a component of the distance below the pressure chamber 26 displacement adjustment mechanism 15 A sealed Ru Tei liquid 30 is filled.

The distance displacement adjustment mechanism 15 A includes a sealed liquid 30 filled in the pressure chamber 28, an actuator 31 and the hydraulic cylinder 32 to the fluid pressure of the sealed liquid 30 is variable. On the other hand, the in-plane displacement adjustment mechanism 13 A includes a sealed liquid 35 that presses the outer peripheral rim portion 34 of the filled sheet 27 to pressure chamber 33 formed at three positions on the inner wall surface of the concave portion 26 of the first holder 7, the It has an actuator 36 and a hydraulic cylinder 37 that make the hydraulic pressure of the enclosed liquid 35 variable. The boundary surface between the outer peripheral rim portion 34 of the thin plate 27 and the enclosed liquid 35 may be in direct contact with each other or may be in contact with each other via an elastic film.

The in-plane displacement detection sensor 14 and the distance displacement detection sensor 16 are constructed such that the first holder 7 is fixed to the main body 9 and the first mirror 5 is movable with respect to the first holder 7. because you are, unlike the first embodiment, the interferometer as a light receiving portion 21, 23 is disposed on the outer periphery of the first mirror 5, the second holder 8 so as to be opposed thereto
Measurement laser as a light-emitting portion 20, 22 is disposed on. The rest of the configuration is the same as that of the first embodiment, so its explanation is omitted.

[0035] In the above configuration, when the signal from the in-plane displacement detecting sensor 14 and the distance displacement detection sensor 16 is different from the initial interference pattern, the controller 18, the distance displacement adjustment mechanism 15 A or plane displacement adjustment mechanism 13 A control signal is output to A. In these adjusting mechanisms 13 A and 15 A , the actuators 31 and 36 are based on the signal from the control device 18.
The hydraulic cylinders 32, 37 to activate the filled liquid 30,
Change the hydraulic pressure of 35. Then, the thin plate 27 is deformed in the optical axis direction due to the pressure fluctuation and moves in the in- plane direction.
It Therefore, the first mirror 5 moves, and the distance between the mirrors or the in-plane position is corrected.

In this case, it is conceivable that instead of the filled liquids 30 and 35, cooling water is caused to flow directly into the pressure chamber 28 of the recess 26 of the first holder 7 and the pressure fluctuation of this cooling water causes the thin plate 27 to be displaced. In such a case, since a large amount of cooling water is made to flow, its pressure fluctuation is large and pressure control is difficult, which is not suitable. Therefore, the pressure control is easier and the fine movement control of the mirror can be realized by making the cooling water and the enclosed liquid independent as in the present embodiment. Incidentally, if the concave pressure chamber 28 for adjusting the distance displacement of the above-mentioned embodiment is partitioned into three sections by partition walls and each is controlled by an actuator, it is orthogonal to the beam axis as in the first embodiment. Two
Adjustment control around the axis is also possible.

[Third Embodiment] FIG. 6 is a configuration diagram of a laser resonator alignment holding device according to a third embodiment of the present invention. In the present embodiment, the first mirror 5 is not moved to adjust the in-plane displacement and the inter-mirror distance as in the first and second embodiments, but the curvature of the first mirror 5 is set for the following reason. The distance between the mirrors is corrected by adjusting. That is, even a total reflection mirror such as the first mirror 5 is inside the laser resonator 3 and a portion of the strong light of the oscillation laser is absorbed, so that the shape change due to the heat load occurs. For this reason, the back surface of the total reflection mirror is cooled, but thermal distortion occurs due to the temperature difference caused by this, and in addition to the displacement in the direction orthogonal to the optical axis and the displacement between the mirrors in the optical axis direction, the curvature of It will change. If the curvature of this mirror changes, the output of the desired wavelength cannot be obtained as in the case of in-plane displacement and distance displacement. The present embodiment is for correcting this.

[0038] Specifically, the laser resonator Alignment <br/> DOO holding device, the mirror curvature adjustment mechanism 40 for displacing the curvature of the first mirror 5 of the total reflection mirror, the curvature displacement of the first mirror 5 Mirror curvature displacement detection mechanism 41 for measuring using light
And a signal from this mirror curvature displacement detection mechanism 41 and the curvature of the reference mirror 42 are compared, and the mirror curvature adjustment mechanism 40
And a control device 18 for outputting a control signal so as to match the curvature of the reference mirror 42 .

The first mirror 5 is composed of an elastic thin film plated with gold on a copper plate, and this thin film is fixed to the front surface of the recess 26 of the first holder 7 . Mirror curvature adjustment mechanism 40 for displacing the first curvature of the mirror 5 of this, the first mirror 5
Pressure chamber 44 formed between the pressure chamber 44 and the recess 26 of the first holder 7, and a filling liquid 45 filled in the pressure chamber 44.
If, it consists actuator 46 and the hydraulic cylinder 47. displaces the curvature of the first mirror 5 by varying the pressure of the sealed liquid 45 based on the signal from the controller 18 Tei <br/> Ru.

The mirror curvature displacement detecting mechanism 41 is a helium / neon laser (hereinafter referred to as a He / Ne laser).
50, a polarization beam splitter 51 that splits the light from the He / Ne laser 50 into the direction of the reference mirror 42 that does not apply a heat load and the first mirror 5, and one of the light from the polarization beam splitter 51 A beam splitter 52 inserted at 45 ° with respect to the laser optical axis 11 so as to be guided to the mirror 5, a polarizing beam splitter 51 and a beam splitter 52, and a polarizing beam splitter 51 and a reference mirror 42, respectively. The first and second wavelength plates 53 and 54, and the light receiving element 55 that guides the light reflected from the first mirror 5 and the reference mirror 42 through the polarization beam splitter 51 and detects the interference fringes thereof.

[0041] The reference mirror 42, as shown, which has been set to a desired curvature, the curvature, as in the mirror curvature <br/> adjusting mechanism 40, the actuator 56 and the hydraulic
The cylinder 57 is controlled by the controller 59, and the filled liquid 60
It can be set arbitrarily by changing the pressure of. The beam splitter 52 is arranged outside the resonator 3 on the output side of the second mirror 6. In addition, the wave plates 53 and 54 are 1 /
The He / Ne laser 50 is used as the light receiving element 55 with a four-wave plate.
Signals whose phase is shifted by ½λ of each round trip with respect to the light emitted from are input. The controller 18 compares the signal from the light receiving element 55 with the initial shape signal, and based on the result, corrects the initial shape signal to the mirror curvature adjusting mechanism 40.
It is composed of a microcomputer that outputs a control signal to. In the figure, 58 indicates a recorder for recording the change in shape. The structures of the second mirror 6, the cooling pipe 29, etc. are the same as in the second embodiment.

[0042] In the above configuration, the shape change of the first mirror 5, the light from the He · Ne laser 50 is introduced from the outside, 2 divided by the polarizing beam splitter 51, a wavelength plate 5
After passing through 3, 54, one is guided to the reference mirror 42 which is not subjected to a heat load, and the other is guided to the first mirror 5 by the beam splitter 52 interposed in the optical axis 11 of the laser. Then, the reflected light from the first mirror 5 and the reference mirror 42
The phase change due to the shape difference from the reflected light from the light receiving element 55
Is incident on the control unit 18, and the received light signal is compared with the received light signal of the initial shape stored in advance in the control device 18, and in the control device 18,
A signal is output to the mirror curvature adjusting mechanism 40 so as to correct this to the initial light receiving signal. Based on this signal, the mirror curvature adjusting mechanism 40 adjusts the adjusting mechanism 15 of the second embodiment.
Similarly, the pressure of the pressure chamber 44 is changed so that the curvature of the first mirror 5 matches the curvature of the reference mirror 42. In this way, the curvature of the first mirror 5 can be displaced according to the reference mirror 42, so that stable output of the laser light can be taken out.

The present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes can be made within the scope of the present invention. For example, in the above embodiment, the adjusting mechanism is provided only on the first mirror, but when both mirrors are concave mirrors, the adjusting mechanism may be provided on both mirrors. Further, the laser resonator alignment holding device may be provided with only one of the in-plane displacement adjusting mechanism and the distance displacement adjusting mechanism. For example, when both mirrors are both plane mirrors, in-plane displacement does not need to be considered so much, so only the distance displacement adjustment mechanism needs to be provided. Further, the configuration of the adjusting mechanism is not limited to the above embodiment, either one of the distance displacement adjusting mechanism and the in-plane displacement adjusting mechanism uses the piezoelectric element as in the first embodiment, and the other uses the piezoelectric element. It goes without saying that a mechanism using the pressure fluctuation of the enclosed liquid as in the second embodiment may be used.

[0044]

According to the invention of claim 1, one mirror
In the plane for adjusting and displacing the
Displacement adjustment mechanism and multiple projectors on the other mirror side
And a laser interferometer provided on one mirror side,
The in-plane displacement of the laser mirror in the direction perpendicular to the laser beam
In-plane displacement detection means and detection from this in-plane displacement detection means
Drive in-plane displacement adjustment mechanism based on signal and initial setting value
Since a control device that outputs a control signal is provided, the laser
Even during operation, the mirror beam in the direction perpendicular to the laser beam of one mirror
Position adjustment to detect in-plane displacement and eliminate in-plane displacement
The relative position of the pair of mirrors of the laser resonator in the in-plane direction.
Alignment can be retained. Also, in-plane displacement
Multiple emitters in the detection means move relative to the other mirror.
Fixedly mounted with multiple laser interferometers on one mirror
Since it is installed so that it cannot move relative to the
The other mirror can be paired without being affected by the vibration of the external members.
The in-plane displacement of one of the mirrors can be detected with high accuracy and
The accuracy of displacement adjustment can be improved.

According to the invention of claim 2, the in-plane displacement adjusting machine
The outer circumference of the mirror and the holder that holds one of the mirrors
Multiple pressure chambers between and and enclosures enclosed in these pressure chambers
Liquid and the pressure of the filled liquid based on the signal from the controller
To move one of the mirrors in-plane
Since it has a configuration that includes the
The in-plane displacement can be adjusted with a simple structure. So
The same effect as that of claim 1 is obtained.

According to the invention of claim 3, between the pair of mirrors
Distance displacement adjustment mechanism to adjust the distance between the other mirror side
On the one mirror side
Includes laser interferometer and detects displacement of distance between mirrors
A distance displacement detecting means is provided, and the control device controls the distance displacement.
Distance based on the detection signal from the detection means and the initial setting value
Since the drive control signal is output to the displacement adjustment mechanism, the laser
Even during operation, the displacement of the distance between the mirrors is constantly detected and the distance is detected.
Adjust the distance between the mirrors to eliminate the displacement
The distance alignment can be maintained. Also,
The plurality of projectors in the distance displacement detection means are the other mirror
Are mounted so that they cannot move relative to each other, and multiple laser interferometers
The mirror of the laser
Between the mirrors without being affected by vibrations of members other than the resonator
The displacement of distance can be detected with high accuracy, and the accuracy of distance displacement adjustment can be improved.
Can be increased. Others Same as claim 1 or claim 2
Produces the same effect .

According to the invention of claim 4, the distance displacement adjustment is performed.
The alignment mechanism consists of a holder that holds one mirror and a mirror.
Between the pressure chamber and the liquid filled in this pressure chamber,
Change the pressure of the filled liquid based on the signal from the controller
An actuator that displaces one mirror in the optical axis direction
Since it has a structure that is equipped with a
With the configuration, it is possible to adjust the displacement of the distance between the mirrors.
It Also, use the enclosed liquid as a coolant for cooling the mirror.
You can also do it.

According to the invention of claim 5, one of the mirrors is
A mirror curvature adjustment mechanism that displaces the curvature is installed
Projector and reference mirror to be used as a reference for the one mirror
And one of the mirrors and the reference mirror projected from the laser beam projector.
Light receiving element that receives the laser light reflected by the laser
And the interference fringes of the laser light received by the light receiving element
To detect the curvature displacement of one mirror via
The position detection means is provided, and the mirror curvature displacement detection means
Based on the detection signal, the mirror curvature adjustment mechanism
Outputs a control signal that matches the curvature with the curvature of the reference mirror.
Since a control device is installed, one side
Detects the curvature displacement of the mirror of the
The adjustment mechanism can eliminate the curvature displacement.
Wear. In addition, the curvature displacement of the mirror can be accurately adjusted via laser light.
The curvature of one mirror can be detected
It is possible to increase the accuracy of matching with.

According to the invention of claim 6, one of the mirrors is
It is composed of an elastic film, and the mirror curvature adjustment mechanism is
Pressure created between the mirror and the holder that holds the mirror.
From the force chamber, the liquid filled in this pressure chamber, and the controller
The pressure of the sealed input is changed based on the signal of
And a configuration including an actuator that displaces the curvature of the
Therefore, the structure of the
-The curvature can be adjusted. In addition, the enclosed liquid is
-It can also be used as a cooling medium for cooling. That
The same effect as that of the other claim 5 is obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a resonator alignment holding device for a laser according to a first embodiment of the present invention.

FIG. 2 is a front view of the first mirror

FIG. 3 is a rear view of the first mirror

FIG. 4 is a rear view of the second mirror

FIG. 5 is a configuration diagram of a resonator alignment holding device according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a resonator alignment holding device according to a third embodiment of the present invention.

FIG. 7 is a side view showing a conventional resonator alignment holding device.

FIG. 8 is an explanatory diagram showing a conventional beam position adjusting operation.

[Explanation of symbols]

 3 Laser resonator 4 Alignment holding device 5,6 Mirror 7,8 Holder 13,13A In-plane displacement adjustment mechanism 14 In-plane displacement detection sensor 15,15A Distance displacement adjustment mechanism 16 Distance displacement detection sensor 18 Control device 20,22 Light emitting part 21, 23 Light receiving part 28 Pressure chamber 31 Actuator 32 Cylinder 33 Pressure chamber 34 Rim part 35 Filled liquid 36 Actuator 37 Cylinder 40 Mirror curvature adjusting mechanism 41 Mirror curvature displacement detecting means 42 Reference mirror 44 Pressure chamber 45 Filled liquid 46 Actuator 47 Cylinder 50 Helium / neon laser 55 light receiving element

Continuation of the front page (56) Reference JP-A-2-110985 (JP, A) JP-A-63-146479 (JP, A) JP-A-2-302083 (JP, A) JP-A-62-42478 (JP , A) JP 63-54790 (JP, A) JP 1-101404 (JP, A) JP 1-178831 (JP, A) JP 63-54791 (JP, A) 2-54262 (JP, U) Japanese Patent Publication 5-37758 (JP, B2)

Claims (6)

(57) [Claims] 1. A pair of opposed mirrors for a laser cavity.
One of the mirrors at right angles to the laser beam
And adjusting the displaced causes plane displacement adjustment mechanism to the other provided relatively immovable with respect to the other mirror
A compound that projects laser light from one side of the mirror to the other.
A number of floodlights and one mirror are immovably mounted
Multiple lasers that respectively receive the laser beams from the multiple projectors.
And a chromatography The interferometer, and one of the laser beams perpendicular plane displacement detecting means for detecting a plane displacement of the mirror, the detection signal and the initial setting value from the in-plane displacement detecting means
Based a controller for outputting a drive control signal to the in-plane displacement adjustment mechanism, lasers both exciter alignment holding device characterized by comprising a. Wherein said plane displacement adjusting mechanism, a plurality of which are formed one of the mirrors between the outer peripheral portion of the sulfo Ruda and one <br/> mirror be displaceably held in its plane direction and the pressure chamber, this
Claim, characterized in that it comprises a sealed liquid sealed in these pressure chambers, and an actuator for one of the mirrors in a plane displaced by varying the pressure of the sealed liquid based on a signal from the control unit 1 lasers co exciter alignment holding device according to. 3. A distance displacement adjusting mechanism for adjusting a distance between the pair of mirrors, and a relative relative to the other mirror.
One mirror is immovably installed and the other mirror side
A plurality of projectors that project laser light toward the
Is mounted on the projector so that it cannot move relative to the laser from multiple projectors.
A plurality of laser interferometers for respectively receiving the light, and a distance displacement detecting means for detecting displacement of the distance between the mirrors, wherein the control device detects a detection signal from the distance displacement detecting means.
Claim and outputs a drive control signal to the distance displacement adjustment mechanism based on the No. and the initial set values 1 or claim 2
Lasers co exciter alignment holding device according to. Wherein said distance displacement adjustment mechanism, sulfo Ruda to movably retain said one mirror in the optical axis direction and one
Square and the pressure chamber formed between the Mirror of the sealed liquid that is sealed in the pressure chamber, the optical axis direction side of the mirror by varying the pressure of the sealed liquid based on a signal from the control device characterized by comprising an actuator for displacing the 請
Lasers co exciter alignment holding device according to Motomeko 3. 5. A pair of opposed mirrors for a laser cavity.
A mirror curvature adjusting mechanism for displacing the curvature of one of the mirrors , a laser light projector, and a base to be used as a reference for the one mirror.
Semi-mirror and one of the mirrors projected from the laser light projector
And the laser light reflected by the reference mirror are received.
The laser light received by the light receiving element
A mirror <br/> chromatography curvature displacement detecting means for detecting a curvature displacement of one mirror through the interference fringes, Mi based on the detection signal from the mirror curvature displacement detecting means
Of one of the mirrors in La chromatography curvature adjustment mechanism curvature of the reference mirror
A laser resonator alignment holding device comprising: a control device that outputs a control signal that matches the curvature . Wherein said one mirror is made of an elastic film, before
Serial curvature adjustment mechanism to vary one of the mirror and the pressure chamber formed between the holder and the sealed liquid sealed in the pressure chamber, the pressure of the sealed liquid based on a signal from the control device lasers according to claim 5, characterized in that an actuator for displacing the curvature of one of the mirrors Te
Co-oscillator alignment holding device.