WO2012176252A1 - Gas laser amplification device - Google Patents

Gas laser amplification device Download PDF

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Publication number
WO2012176252A1
WO2012176252A1 PCT/JP2011/064013 JP2011064013W WO2012176252A1 WO 2012176252 A1 WO2012176252 A1 WO 2012176252A1 JP 2011064013 W JP2011064013 W JP 2011064013W WO 2012176252 A1 WO2012176252 A1 WO 2012176252A1
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WO
WIPO (PCT)
Prior art keywords
mirror
laser
gas
opening
housing
Prior art date
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PCT/JP2011/064013
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French (fr)
Japanese (ja)
Inventor
陽一 谷野
山本　達也
瀬口　正記
西前　順一
藤川　周一
Original Assignee
三菱電機株式会社
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to PCT/JP2011/064013 priority Critical patent/WO2012176252A1/en
Priority to TW100125937A priority patent/TW201301693A/en
Publication of WO2012176252A1 publication Critical patent/WO2012176252A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/08—Construction or shape of optical resonators or components thereof
    • H01S3/081—Construction or shape of optical resonators or components thereof comprising three or more reflectors
    • H01S3/0813—Configuration of resonator
    • H01S3/0816—Configuration of resonator having 4 reflectors, e.g. Z-shaped resonators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/03—Constructional details of gas laser discharge tubes
    • H01S3/034—Optical devices within, or forming part of, the tube, e.g. windows, mirrors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/22—Gases
    • H01S3/223—Gases the active gas being polyatomic, i.e. containing two or more atoms
    • H01S3/2232—Carbon dioxide (CO2) or monoxide [CO]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/03—Constructional details of gas laser discharge tubes

Definitions

  • the present invention relates to a gas laser amplifier for amplifying laser light using a laser medium such as CO 2 .
  • a general gas laser oscillator includes a low-pressure container filled with a laser medium gas (for example, a mixed gas composed of carbon dioxide gas, helium gas, nitrogen gas, etc.), and a rear mirror provided between the laser medium gas and an output mirror.
  • a laser medium gas for example, a mixed gas composed of carbon dioxide gas, helium gas, nitrogen gas, etc.
  • An optical resonator that makes laser oscillation by reciprocating a laser beam, a laser medium gas supply unit that supplies laser medium gas to a low-pressure vessel, a laser medium gas exhaust unit that exhausts laser medium gas, and supplies energy to the laser medium gas
  • a laser medium gas excitation means for example, a discharge device
  • a laser medium gas circulation device that circulates the laser medium gas
  • a cooling means that cools the laser medium gas that has been excited to a high temperature.
  • Patent Document 1 As a countermeasure against parasitic oscillation, in Patent Document 1 described below, a convex mirror is used for at least a part of a plurality of folding mirrors in an orthogonal gas laser oscillator in which a plurality of folding mirrors are provided between an output mirror and a rear mirror to form an optical resonator. It has been proposed.
  • the opposing folding mirror is a combination of a convex mirror and a convex mirror, or a combination of a convex mirror and a plane mirror (installed in parallel to each other). Since the laser beam between the folding mirrors quickly diverges from the folding mirror, the limit gain (threshold value) for maintaining laser oscillation increases. As a result, the occurrence of parasitic oscillation between the folding mirrors is suppressed.
  • Patent Document 2 discloses a gas laser amplifying apparatus configured such that incident laser light is vertically incident on a feedback mirror so that the laser light passes through the same discharge region twice.
  • a special optical system combining a wave plate and a polarizer is indispensable for separating the outgoing laser light.
  • An object of the present invention is to provide a gas laser amplifier that has a high amplification gain and can suppress parasitic oscillation with a simple configuration.
  • one embodiment of the present invention relates to a gas laser amplifying apparatus, A housing for enclosing the laser gas; A discharge electrode provided in the housing for exciting the laser gas; At least two mirrors provided in the housing for reflecting the laser light amplified by the laser gas; A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing;
  • the first mirror is a folding mirror that is disposed so as to reflect light that has passed through a discharge region determined by a certain pair of discharge electrodes of the discharge electrodes and to guide the light again into the discharge region;
  • the second mirror is a folding mirror installed so as to reflect the light reflected by the first mirror and guide it again into the discharge region, The first and second mirrors are installed non-parallel to each other.
  • a gas laser amplification device A housing for enclosing the laser gas; A discharge electrode provided in the housing for exciting the laser gas; At least three mirrors provided in the housing for reflecting the laser light amplified by the laser gas; A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing;
  • the first mirror is a folding mirror that is disposed so as to reflect light that has passed through a discharge region determined by a certain pair of discharge electrodes of the discharge electrodes and to guide the light again into the discharge region;
  • the second mirror is a folding mirror installed so as to reflect the light reflected by the first mirror and guide it again into the discharge region,
  • the third mirror is a folding mirror that is installed so as to reflect the light reflected by the second mirror and guide it back into the discharge region.
  • the first, second and third mirrors are installed non-parallel to each other.
  • a gas laser amplification device A housing for enclosing the laser gas; A pair of discharge electrodes provided in the housing for exciting the laser gas; At least two mirrors provided in the housing for reflecting the laser light amplified by the laser gas; A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing; A first opening member having a first opening and a fourth opening is disposed near the first mirror, A second opening member having a second opening and a third opening is disposed near the second mirror, The first straight line connecting the center of the first opening and the center of the second opening is in a position twisted with respect to the second straight line connecting the center of the third opening and the center of the fourth opening; The laser light passes through the first opening, the second opening, the first mirror, the second opening, the third opening, the second mirror, the third opening, and the fourth opening in this order.
  • a gas laser amplification device having a high amplification gain can be realized by adopting a mirror arrangement in which laser light passes through the discharge region a plurality of times. Further, by adjusting the folding mirrors so that they are not parallel to each other, parasitic oscillation can be suppressed with a simple configuration.
  • Embodiment 1 of this invention It is a perspective view which shows Embodiment 1 of this invention. It is a perspective view which shows Embodiment 2 of this invention. It is explanatory drawing which defines a discharge area. It is a perspective view which shows Embodiment 3 of this invention. It is a graph which shows the relationship between the parallelism of a mirror, and parasitic oscillation. It is a perspective view which shows Embodiment 4 of this invention. It is the side view which looked at the relative position of each opening of an opening member, a mirror, and a window member from the A direction of FIG. It is a perspective view which shows an example of the shape of two opening members.
  • FIG. FIG. 1 is a perspective view showing Embodiment 1 of the present invention.
  • the gas laser amplifying apparatus is provided in the housing 1 for enclosing a laser gas such as CO 2 , a pair of discharge electrodes 15 and 16 for exciting the laser gas, and the housing 1.
  • Mirrors 4 and 5 for reflecting the laser light amplified by the laser gas, and window members 2 and 3 provided in the housing 1 for allowing the laser light to pass between the inside and the outside of the housing. Composed.
  • a window member 2 is provided on one side of the housing 1, and a window member 3 is provided on the opposite side.
  • the mirror 4 is attached to the side surface of the housing 1 in which the window member 2 is arranged, and the mirror 5 is attached to the side surface of the housing 1 in which the window member 3 is arranged.
  • the mirrors 4 and 5 are preferably flat mirrors having a flat optical surface, and are attached to the side surface of the housing 1 via an angle adjustment mechanism so that the attachment angle can be finely adjusted.
  • the mirrors 4 and 5 are installed non-parallel to each other, and are set so that the normal of the optical surface of the mirror 4 and the normal of the optical surface of the mirror 5 form an angle of about 1 mrad, for example.
  • the discharge electrodes 15 and 16 are configured as electrodes metallized on the ceramic plates 11 and 12 which are electrode support members. When an AC voltage is applied between the discharge electrodes 15 and 16, a discharge occurs between the discharge electrode 15 and the discharge electrode 16, thereby exciting the laser gas.
  • FIG. 4 is an explanatory diagram for defining the discharge region.
  • the discharge region 19 is defined as a rectangular parallelepiped region sandwiched between the discharge electrodes 15 and 16. Accordingly, the laser gas existing in the discharge region 19 is excited, and the laser light passing through the discharge region 19 is amplified.
  • the mirror 4 is a folding mirror that is installed so as to reflect the light that has passed through the discharge region and guide it again into the same discharge region.
  • the mirror 5 is a folding mirror installed so as to reflect the light reflected by the mirror 4 and guide it again into the same discharge region. Accordingly, the laser light passes through the discharge region three times in the order of the optical path from the window member 2 to the mirror 4, the optical path from the mirror 4 to the mirror 5, and the optical path from the mirror 5 to the window member 3, for a total of three times. It will be amplified. Furthermore, by increasing the number of folding mirrors, the number of passes through the discharge region is also increased, and more efficient light amplification is possible.
  • a high amplification gain can be obtained by passing the laser beam through the same discharge region a plurality of times.
  • gain G ⁇ exp [g 0 ⁇ L] is established.
  • g 0 is a small signal gain per unit length
  • L is a geometric length in the longitudinal direction of the excitation medium, that is, a length in the longitudinal direction of the discharge region.
  • the gain of the laser beam does not exceed exp [g 0 ⁇ L] which is a gain at the time of a small signal (for example, (See W. Rigrod, Journal of Applied Physics Vol. 34 No. 9 (1963) p2602. Small signal and small signal gain refer to the condition of a minute input whose input is nearly zero).
  • the mirrors 4 and 5 having a flat optical surface are installed so as to form an angle shifted by about 1 mrad from the parallel to each other, thereby providing an effect of suppressing parasitic oscillation with a simple configuration.
  • the mirrors 4 and 5 serve as resonators, and laser oscillation is performed using spontaneously emitted light generated in the discharge region determined by the discharge electrodes 15 and 16 as seed light. Occur. This is called parasitic oscillation. When parasitic oscillation occurs, excitation energy is consumed even outside the original oscillation region, so that the efficiency of the laser amplifier is reduced.
  • the installation angle of mirrors 4 and 5 is defined by the angle between two mirror surfaces (0 degree or more and less than 90 degrees). Even in a configuration in which the mirror surface is not flat, for example, a configuration having a convex surface or a concave surface, parasitic oscillation can be suppressed by setting the angles of the mirror surfaces to be non-parallel to each other by a minute angle as described above. It goes without saying for those skilled in the art that the orientation of the mirror surface which is not a plane can be defined by the contact surface of the mirror surface at the center of the laser beam hitting the mirror.
  • the incident laser beam 21 and the emitted laser beam 22 are configured so as not to return on the same axis, thereby obtaining the effect of reducing the return light to the oscillator with a simple configuration.
  • the laser beam is folded n times and n + 1 times. If the two mirrors that are folded back are installed so that all natural numbers n corresponding to the number of mirrors form a small angle from parallel (1 mrad as a guide), the same effect can be obtained.
  • the minute angle of the folding mirror may be 1 mrad or more, and the same effect can be obtained as long as the laser light amplified in the discharge region can pass through the same discharge region again.
  • FIG. FIG. 2 is a perspective view showing Embodiment 2 of the present invention.
  • the laser beam is configured to pass through the same discharge region six times.
  • the gas laser amplifying apparatus is provided in the housing 1 for enclosing a laser gas such as CO 2 , a pair of discharge electrodes 15 and 16 for exciting the laser gas, and the housing 1.
  • a laser gas such as CO 2
  • a pair of discharge electrodes 15 and 16 for exciting the laser gas
  • the housing 1 Mirrors 4, 5, 6 for reflecting the laser light amplified by the laser gas, and a window member 2 provided in the housing 1 for allowing the laser light to pass between the inside and the outside of the housing Composed.
  • a window member 2 is provided on one side of the housing 1, and a mirror 5 is attached to the same side.
  • Mirrors 4 and 6 are attached to the opposite side surfaces.
  • the mirrors 4, 5, and 6 are preferably flat mirrors having a flat optical surface, and are attached to the side surface of the housing 1 via an angle adjustment mechanism so that the attachment angle can be finely adjusted.
  • the mirrors 4 and 5 are installed non-parallel to each other, and are set so that the normal of the optical surface of the mirror 4 and the normal of the optical surface of the mirror 5 form an angle of about 1 mrad, for example.
  • the mirrors 5 and 6 are also installed non-parallel to each other, and are set so that the normal of the optical surface of the mirror 5 and the normal of the optical surface of the mirror 6 form an angle of about 10 mrad, for example.
  • the discharge electrodes 15 and 16 are configured as electrodes metallized on the ceramic plates 11 and 12 which are electrode support members. As shown in FIG. 3, the discharge region 19 is defined as a rectangular parallelepiped region sandwiched between the discharge electrodes 15 and 16. When an AC voltage is applied between the discharge electrodes 15 and 16, a discharge is generated between the discharge electrode 15 and the discharge electrode 16, thereby exciting the laser gas, and as a result, the laser light passing through the discharge region 19 is amplified.
  • the mirror 4 is a folding mirror that is installed so as to reflect the light that has passed through the discharge region and guide it again into the same discharge region.
  • the mirror 5 is a folding mirror installed so as to reflect the light reflected by the mirror 4 and guide it again into the same discharge region.
  • the mirror 6 is a folding mirror installed so as to reflect the light reflected by the mirror 5 and guide it again into the same discharge region. Therefore, the laser light travels from the window member 2 to the mirror 4, from the mirror 4 to the mirror 5, from the mirror 5 to the mirror 6, from the mirror 6 to the mirror 5, and from the mirror 5 to the mirror 4.
  • the discharge region passes through the discharge path six times in the order of the optical path and the optical path from the mirror 4 to the window member 3, and is amplified six times in total. Furthermore, by increasing the number of folding mirrors, the number of passes through the discharge region is also increased, and more efficient light amplification is possible.
  • the relationship of gain G emitted light power Po / incident light power Pi ⁇ exp [g 0 ⁇ L] is established for the amplification gain.
  • the mirrors 4, 5 and 6 whose optical surfaces are flat are installed so as to have an angle shifted by about 1 mrad from the parallel, thereby providing an effect of suppressing parasitic oscillation with a simple configuration. Yes.
  • any two of the mirrors 4, 5, and 6 are installed in parallel to each other, these parallel mirrors become resonators, and the spontaneously emitted light generated in the discharge region is used as seed light. As a result, parasitic oscillation occurs. When parasitic oscillation occurs, excitation energy is consumed even outside the original oscillation region, so that the efficiency of the laser amplifier is reduced.
  • the mirrors 4 and 5 are installed so as to form an angle shifted by about 1 mrad from the parallel, and the mirrors 5 and 6 are installed so as to form an angle shifted by about 10 mrad from the parallel. Therefore, the diffraction loss in the optical path that makes one round trip between the mirrors 4 and 5, the optical path that makes one round trip between the mirrors 5 and 6, and the optical path that makes one round trip between the mirrors 4, 5, and 6 increases. Therefore, parasitic oscillation using the spontaneous emission light generated in the discharge region as seed light does not occur, and parasitic oscillation can be suppressed with a simple configuration.
  • the incident laser beam 21 is inclined at an angle of, for example, about 10 mrad with respect to the normal of the optical surface of the mirror 6 so that the optical axis of the incident laser beam 21 and the optical axis of the emitted laser beam 22 are not coaxial.
  • the configuration in which the incident laser beam 21 and the emitted laser beam 22 pass through one window member 2 is shown.
  • the discharge electrodes 15 and 16 are attached to the casing 1 by other methods. Even if fixed, the same effect can be obtained.
  • CO 2 is used as the laser medium.
  • another laser medium such as an excimer laser.
  • FIG. FIG. 4 is a perspective view showing Embodiment 3 of the present invention.
  • the optical axis adjustment method of the gas laser amplifier according to the present invention will be described.
  • the gas laser amplifying apparatus according to the first embodiment will be described as an example, but the same can be applied to the gas laser amplifying apparatus according to the second embodiment.
  • a damper 42 is installed as a laser absorption mechanism on the outside of the housing 1 so as to intersect with the optical axis of the incident laser light, and on the other hand, for example, a thermopile detector or the like so as to intersect with the optical axis of the emitted laser light.
  • the power detector 41 is installed.
  • auxiliary mirror (not shown) or the like on the optical axis of the incident laser light
  • guide light for example, helium neon laser light
  • the optical axis of the guide light is adjusted so that the guide light passes through the center of the window member 2 and hits the center of the optical surface of the mirror 4.
  • the installation angle of the mirror 4 is adjusted so that the guide light reflected by the mirror 4 strikes the center of the optical surface of the mirror 5. Subsequently, the installation angle of the mirror 5 is adjusted so that the guide light reflected by the mirror 5 passes through the center of the window member 3. Thereafter, the auxiliary mirror is removed and the introduction of the guide light is stopped.
  • an AC voltage is applied to the discharge electrodes 15 and 16 so that the laser gas is excited in a discharge region determined by the discharge electrodes 15 and 16.
  • the mirrors 4 and 5 form an angle ⁇ a that is extremely close to each other in parallel (for example, an angle smaller than 1 mrad order)
  • the parasitic oscillation light 23 is generated between the mirrors 4 and 5.
  • Part of the parasitic oscillation light 23 is diffracted by the mirror 5 to become diffracted light 24, passes through the window member 3, reaches the power detector 41, and further diffracted by the mirror 4 to become diffracted light 25. 3 to reach the damper 41.
  • the relative angle of the mirrors 4 and 5 is larger than the angle ⁇ a, the parasitic oscillation does not occur, and the power detector 41 does not detect the parasitic oscillation light.
  • the optical axes of the mirrors 4 and 5 are adjusted so that the relative angle of the mirrors 4 and 5 is equal to or smaller than the angle ⁇ a, and parasitic oscillation occurs. Alignment state to be performed.
  • the mirrors 4 and 5 can be adjusted to be completely parallel to each other.
  • the parasitic oscillation power rapidly decreases. .
  • the parasitic oscillation power is set to be minimum, the parasitic oscillation can be surely prevented.
  • FIG. 5 is a graph showing the relationship between mirror parallelism and parasitic oscillation.
  • the vertical axis represents the parasitic oscillation power (linear, arbitrary unit) detected by the power detector 41, and the horizontal axis represents the relative angle (mrad) of the mirrors 4 and 5.
  • the alignment state in which the parasitic oscillation power is maximized is defined as the origin (0 mrad). From this graph, it can be seen that if the relative angle of the mirrors 4 and 5 is set to about 1 mrad or more, the parasitic oscillation power is minimized and the parasitic oscillation is suppressed.
  • the optical axis of the gas laser amplifying apparatus can be adjusted so that parasitic oscillation can be suppressed with a simple procedure.
  • FIG. FIG. 6 is a perspective view showing Embodiment 4 of the present invention.
  • the optical axis adjustment of the gas laser amplifier according to the present invention will be described.
  • the gas laser amplifying apparatus according to the first embodiment will be described as an example, but the present invention can be similarly applied to the gas laser amplifying apparatus according to the second and third embodiments.
  • two opening members 31, 32 are installed in parallel to each other at a predetermined interval, for example, 1 m along the optical path of the laser beam.
  • the opening member 31 has two openings 33 and 34, and the opening member 32 also has two openings 35 and 36.
  • These openings 33 to 36 have a function of mechanically limiting the space through which the laser light passes, and the number of openings increases as the number of optical paths in the housing 1 increases.
  • a light source 51 that generates guide light (for example, helium neon laser light) 28 is installed outside the housing 1.
  • FIG. 8 is a perspective view showing an example of the shape of the opening members 31 and 32.
  • the opening member 31 and the opening member 32 have the same shape except for the position of the opening.
  • the centers of the openings 33 and 34 of the opening member 31 are provided on the axis of symmetry of the opening member 31.
  • the position of the opening 36 with respect to the opening member 32 is the same as the position of the opening 34 with respect to the opening member 31, but the position of the opening 35 with respect to the opening member 32 is, for example, 2 mm than the position of the opening 35 with respect to the opening member 31. They are shifted to the right (the direction opposite to the direction A in FIG. 6).
  • FIG. 7 is a side view of the relative positions of the openings 33 and 34 of the opening member 31, the openings 35 and 36 of the opening member 32, the mirrors 4 and 5, and the window members 2 and 3 from the direction A in FIG.
  • the center of the opening 35 with respect to the opening member 31 is located 2 mm before the paper surface of FIG. Therefore, the first straight line connecting the center of the opening 33 and the center of the opening 35 is a twisted position with respect to the second straight line connecting the center of the opening 34 and the center of the opening 36.
  • guide light 28 is introduced along the optical axis of each mirror.
  • the relative angle of the mirrors 4 and 5 (Mrad) is set to about 1 mrad.
  • the optical axis of the gas laser amplifying apparatus can be adjusted so that parasitic oscillation can be suppressed with a simple procedure.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • Lasers (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)

Abstract

A gas laser amplification device according to the present invention is configured from: an enclosure for enclosing a laser gas such as CO2; a pair of discharge electrodes for exciting the laser gas which are provided within said enclosure; mirrors for reflecting a laser beam amplified by the laser gas which are provided within said enclosure; and a window member or the like for allowing a laser beam to be transmitted between the interior and the exterior of the enclosure. A first mirror is a return mirror provided so as to reflect a beam that has been transmitted through an electric discharge area and guide said beam into the same electric discharge area once more. A second mirror is a return mirror provided so as to reflect the beam returned by the first mirror and guide said beam into the same electric discharge area once more. The first and second mirrors are arranged such that said mirrors are not parallel to each other. This configuration exhibits a high gain in amplification and makes it possible to easily control parasitic oscillation.

Description

ガスレーザ増幅装置Gas laser amplifier
　本発明は、ＣＯ２等のレーザ媒質を用いてレーザ光を増幅するためのガスレーザ増幅装置に関する。 The present invention relates to a gas laser amplifier for amplifying laser light using a laser medium such as CO 2 .
　一般的なガスレーザ発振器は、レーザ媒質ガス（例えば、炭酸ガス、ヘリウムガス、窒素ガスなどからなる混合ガス）を充填した低圧容器と、レーザ媒質ガスを挟んで設けたリアミラーと出力ミラーとの間にレーザビームを往復させてレーザ発振させる光共振器と、レーザ媒質ガスを低圧容器に供給するレーザ媒質ガス供給手段と、レーザ媒質ガスを排気するレーザ媒質ガス排気手段と、レーザ媒質ガスにエネルギーを供給するレーザ媒質ガス励起手段（例えば、放電装置）と、レーザ媒質ガスを循環させるレーザ媒質ガス循環装置と、励起されて高温になったレーザ媒質ガスを冷却する冷却手段などで構成される。 A general gas laser oscillator includes a low-pressure container filled with a laser medium gas (for example, a mixed gas composed of carbon dioxide gas, helium gas, nitrogen gas, etc.), and a rear mirror provided between the laser medium gas and an output mirror. An optical resonator that makes laser oscillation by reciprocating a laser beam, a laser medium gas supply unit that supplies laser medium gas to a low-pressure vessel, a laser medium gas exhaust unit that exhausts laser medium gas, and supplies energy to the laser medium gas A laser medium gas excitation means (for example, a discharge device) that circulates, a laser medium gas circulation device that circulates the laser medium gas, and a cooling means that cools the laser medium gas that has been excited to a high temperature.
　こうしたガスレーザ発振器において、寄生発振が発生すると、本来の発振領域以外においても励起エネルギーが消費されるため、レーザ発振器の効率が低下してしまう。 In such a gas laser oscillator, when parasitic oscillation occurs, excitation energy is consumed even outside the original oscillation region, so that the efficiency of the laser oscillator is reduced.
　寄生発振の対策として、下記特許文献１では、出力ミラーとリアミラーの間に複数の折返しミラーを設けて光共振器を構成した直交型ガスレーザ発振器において、複数の折返しミラーの少なくとも一部に凸面鏡を用いることが提案されている。 As a countermeasure against parasitic oscillation, in Patent Document 1 described below, a convex mirror is used for at least a part of a plurality of folding mirrors in an orthogonal gas laser oscillator in which a plurality of folding mirrors are provided between an output mirror and a rear mirror to form an optical resonator. It has been proposed.
　こうした構成により、対向する折返しミラーは、凸面鏡と凸面鏡の組合せ、または、凸面鏡と平面鏡の組合せ（互いに平行に設置されている）となる。折返しミラー間のレーザビームは急速に折返しミラーの外へ発散していくため、レーザ発振を維持するための限界ゲイン（しきい値）が大きくなる。その結果、折返しミラー間の寄生発振の発生を抑制している。 With such a configuration, the opposing folding mirror is a combination of a convex mirror and a convex mirror, or a combination of a convex mirror and a plane mirror (installed in parallel to each other). Since the laser beam between the folding mirrors quickly diverges from the folding mirror, the limit gain (threshold value) for maintaining laser oscillation increases. As a result, the occurrence of parasitic oscillation between the folding mirrors is suppressed.
　また、下記特許文献２には、入射レーザ光をフィードバックミラーに垂直に入射させて、レーザ光が同一の放電領域を２回通過するように構成したガスレーザ増幅装置が開示されている。この構成では、増幅された出射レーザ光が入射レーザ光と同軸の光路上に戻るため、出射レーザ光を分離するためには、波長板と偏光子を組み合わせた特別の光学系が不可欠になる。 Also, Patent Document 2 below discloses a gas laser amplifying apparatus configured such that incident laser light is vertically incident on a feedback mirror so that the laser light passes through the same discharge region twice. In this configuration, since the amplified outgoing laser light returns to the optical path coaxial with the incident laser light, a special optical system combining a wave plate and a polarizer is indispensable for separating the outgoing laser light.
特開平１１－８７８０７号公報Japanese Patent Laid-Open No. 11-87807 特開２００８－８５２９２号公報JP 2008-85292 A 特開２００３－０９２１９９号公報JP 2003-092199 A 特開昭６０－０２８２８８号公報Japanese Unexamined Patent Publication No. 60-028288
　特許文献１の構成では、折返しミラーとして凸面鏡を用いているため、レーザ光が凸面鏡によって拡散してしまい、入射レーザ光または出射レーザ光に対するビーム整形用の光学系が必要になり、全体として構成が複雑になる。 In the configuration of Patent Document 1, since the convex mirror is used as the folding mirror, the laser beam is diffused by the convex mirror, and an optical system for beam shaping with respect to the incident laser beam or the emitted laser beam is required, and the configuration as a whole is configured. It becomes complicated.
　特許文献２の構成では、光学系が複雑になり、光学損失も増加してしまう。 In the configuration of Patent Document 2, the optical system becomes complicated and the optical loss increases.
　本発明の目的は、増幅利得が高く、かつ簡便な構成で寄生発振を抑制できるガスレーザ増幅装置を提供することである。 An object of the present invention is to provide a gas laser amplifier that has a high amplification gain and can suppress parasitic oscillation with a simple configuration.
　上記目的を達成するために、本発明の一態様は、ガスレーザ増幅装置に関するものであり、
　レーザガスを封入するための筐体と、
　筐体内に設けられ、レーザガスを励起するための放電電極と、
　筐体内に設けられ、レーザガスによって増幅されたレーザ光を反射するための少なくとも２枚のミラーと、
　筐体に設けられ、筐体内部と外部の間でレーザ光の通過を許容するためのウインドウ部材とを備え、
　第１のミラーは、前記放電電極のうちのある一対の放電電極によって決まる放電領域内を通過した光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
　第２のミラーは、第１のミラーによって折り返された光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
　第１および第２のミラーは、互いに非平行に設置される。 In order to achieve the above object, one embodiment of the present invention relates to a gas laser amplifying apparatus,
A housing for enclosing the laser gas;
A discharge electrode provided in the housing for exciting the laser gas;
At least two mirrors provided in the housing for reflecting the laser light amplified by the laser gas;
A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing;
The first mirror is a folding mirror that is disposed so as to reflect light that has passed through a discharge region determined by a certain pair of discharge electrodes of the discharge electrodes and to guide the light again into the discharge region;
The second mirror is a folding mirror installed so as to reflect the light reflected by the first mirror and guide it again into the discharge region,
The first and second mirrors are installed non-parallel to each other.
　また本発明の一態様は、ガスレーザ増幅装置に関するものであり、
　レーザガスを封入するための筐体と、
　筐体内に設けられ、レーザガスを励起するための放電電極と、
　筐体内に設けられ、レーザガスによって増幅されたレーザ光を反射するための少なくとも３枚のミラーと、
　筐体に設けられ、筐体内部と外部の間でレーザ光の通過を許容するためのウインドウ部材とを備え、
　第１のミラーは、前記放電電極のうちのある一対の放電電極によって決まる放電領域内を通過した光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
　第２のミラーは、第１のミラーによって折り返された光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
　第３のミラーは、第２のミラーによって折り返された光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
　第１、第２および第３のミラーは、互いに非平行に設置される。 Another embodiment of the present invention relates to a gas laser amplification device,
A housing for enclosing the laser gas;
A discharge electrode provided in the housing for exciting the laser gas;
At least three mirrors provided in the housing for reflecting the laser light amplified by the laser gas;
A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing;
The first mirror is a folding mirror that is disposed so as to reflect light that has passed through a discharge region determined by a certain pair of discharge electrodes of the discharge electrodes and to guide the light again into the discharge region;
The second mirror is a folding mirror installed so as to reflect the light reflected by the first mirror and guide it again into the discharge region,
The third mirror is a folding mirror that is installed so as to reflect the light reflected by the second mirror and guide it back into the discharge region.
The first, second and third mirrors are installed non-parallel to each other.
　また本発明の一態様は、ガスレーザ増幅装置に関するものであり、
　レーザガスを封入するための筐体と、
　筐体内に設けられ、レーザガスを励起するための一対の放電電極と、
　筐体内に設けられ、レーザガスによって増幅されたレーザ光を反射するための少なくとも２枚のミラーと、
　筐体に設けられ、筐体内部と外部の間でレーザ光の通過を許容するためのウインドウ部材とを備え、
　第１のミラー付近には、第１開口および第４開口を有する第１開口部材が配置され、
　第２のミラー付近には、第２開口および第３開口を有する第２開口部材が配置され、
　第１開口の中心と第２開口の中心とを結ぶ第１直線が、第３開口の中心と第４開口の中心とを結ぶ第２直線に対してねじれの位置にあり、
　レーザ光は、第１開口、第２開口、第１のミラー、第２開口、第３開口、第２のミラー、第３開口、第４開口の順に通過する。 Another embodiment of the present invention relates to a gas laser amplification device,
A housing for enclosing the laser gas;
A pair of discharge electrodes provided in the housing for exciting the laser gas;
At least two mirrors provided in the housing for reflecting the laser light amplified by the laser gas;
A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing;
A first opening member having a first opening and a fourth opening is disposed near the first mirror,
A second opening member having a second opening and a third opening is disposed near the second mirror,
The first straight line connecting the center of the first opening and the center of the second opening is in a position twisted with respect to the second straight line connecting the center of the third opening and the center of the fourth opening;
The laser light passes through the first opening, the second opening, the first mirror, the second opening, the third opening, the second mirror, the third opening, and the fourth opening in this order.
　本発明によれば、レーザ光が放電領域内を複数回通過するようなミラー配置を採用することによって、高い増幅利得を有するガスレーザ増幅装置を実現できる。また、折り返しミラー同士が互いに非平行になるように調整することにより、簡便な構成で寄生発振を抑制できる。 According to the present invention, a gas laser amplification device having a high amplification gain can be realized by adopting a mirror arrangement in which laser light passes through the discharge region a plurality of times. Further, by adjusting the folding mirrors so that they are not parallel to each other, parasitic oscillation can be suppressed with a simple configuration.
本発明の実施の形態１を示す斜視図である。It is a perspective view which shows Embodiment 1 of this invention. 本発明の実施の形態２を示す斜視図である。It is a perspective view which shows Embodiment 2 of this invention. 放電領域を定義する説明図である。It is explanatory drawing which defines a discharge area. 本発明の実施の形態３を示す斜視図である。It is a perspective view which shows Embodiment 3 of this invention. ミラーの平行度と寄生発振の関係を示すグラフである。It is a graph which shows the relationship between the parallelism of a mirror, and parasitic oscillation. 本発明の実施の形態４を示す斜視図である。It is a perspective view which shows Embodiment 4 of this invention. 開口部材の各開口、ミラーおよびウインドウ部材の相対位置を図６のＡ方向から見た側面図である。It is the side view which looked at the relative position of each opening of an opening member, a mirror, and a window member from the A direction of FIG. ２つの開口部材の形状の一例を示す斜視図である。It is a perspective view which shows an example of the shape of two opening members.
実施の形態１．
　図１は、本発明の実施の形態１を示す斜視図である。ガスレーザ増幅装置は、ＣＯ２等のレーザガスを封入するための筐体１と、筐体１内に設けられ、レーザガスを励起するための一対の放電電極１５，１６と、筐体１内に設けられ、レーザガスによって増幅されたレーザ光を反射するためのミラー４，５と、筐体１に設けられ、筐体内部と外部の間でレーザ光の通過を許容するためのウインドウ部材２，３などで構成される。 Embodiment 1 FIG.
FIG. 1 is a perspective view showing Embodiment 1 of the present invention. The gas laser amplifying apparatus is provided in the housing 1 for enclosing a laser gas such as CO 2 , a pair of discharge electrodes 15 and 16 for exciting the laser gas, and the housing 1. Mirrors 4 and 5 for reflecting the laser light amplified by the laser gas, and window members 2 and 3 provided in the housing 1 for allowing the laser light to pass between the inside and the outside of the housing. Composed.
　筐体１の一側面にはウインドウ部材２が設けられ、その対向側面にはウインドウ部材３が設けられている。ミラー４は、ウインドウ部材２が配置された筐体１の側面に取り付けられ、ミラー５は、ウインドウ部材３が配置された筐体１の側面に取り付けられる。 A window member 2 is provided on one side of the housing 1, and a window member 3 is provided on the opposite side. The mirror 4 is attached to the side surface of the housing 1 in which the window member 2 is arranged, and the mirror 5 is attached to the side surface of the housing 1 in which the window member 3 is arranged.
　ミラー４，５は、光学面が平面である平面ミラーであることが好ましく、取り付け角度の微調節が可能なように、角度調整機構を介して筐体１の側面に取り付けられる。ミラー４，５は、互いに非平行に設置されており、ミラー４の光学面の法線とミラー５の光学面の法線が、例えば、約１ｍｒａｄの角度を成すように設置される。 The mirrors 4 and 5 are preferably flat mirrors having a flat optical surface, and are attached to the side surface of the housing 1 via an angle adjustment mechanism so that the attachment angle can be finely adjusted. The mirrors 4 and 5 are installed non-parallel to each other, and are set so that the normal of the optical surface of the mirror 4 and the normal of the optical surface of the mirror 5 form an angle of about 1 mrad, for example.
　放電電極１５，１６は、電極支持部材であるセラミック板１１，１２にメタライズされた電極として構成される。放電電極１５，１６間に交流電圧を印加すると、放電電極１５と放電電極１６の間で放電が生じ、これによりレーザガスが励起される。 The discharge electrodes 15 and 16 are configured as electrodes metallized on the ceramic plates 11 and 12 which are electrode support members. When an AC voltage is applied between the discharge electrodes 15 and 16, a discharge occurs between the discharge electrode 15 and the discharge electrode 16, thereby exciting the laser gas.
　図４は、放電領域を定義する説明図である。放電領域１９は、放電電極１５，１６に挟まれた直方体の領域として定義される。従って、この放電領域１９内に存在するレーザガスが励起され、放電領域１９を通過するレーザ光が増幅される。 FIG. 4 is an explanatory diagram for defining the discharge region. The discharge region 19 is defined as a rectangular parallelepiped region sandwiched between the discharge electrodes 15 and 16. Accordingly, the laser gas existing in the discharge region 19 is excited, and the laser light passing through the discharge region 19 is amplified.
　図１に戻って、外部のレーザ発振器またはレーザ増幅器からのレーザ光がウインドウ部材２を通過し、入射レーザ光２１としてガスレーザ増幅装置に入射すると、ミラー４で反射し、続いてミラー５で反射して、ウインドウ部材３を通過すると、最終的に出射レーザ光２２として出射される。 Returning to FIG. 1, when laser light from an external laser oscillator or laser amplifier passes through the window member 2 and enters the gas laser amplifying apparatus as incident laser light 21, it is reflected by the mirror 4 and subsequently reflected by the mirror 5. After passing through the window member 3, the laser beam is finally emitted as the emitted laser beam 22.
　ミラー４は、放電領域内を通過した光を反射させて、再び同じ放電領域内へ導くように設置された折り返しミラーである。ミラー５は、ミラー４によって折り返された光を反射させて、再び同じ放電領域内へ導くように設置された折り返しミラーである。従って、レーザ光は、ウインドウ部材２からミラー４へ向かう光路、ミラー４からミラー５へ向かう光路、ミラー５からウインドウ部材３へ向かう光路の順に放電領域を３回通過するようになり、計３回増幅されることになる。さらに、折り返しミラーを増やすことによって、放電領域の通過回数も増加して、より効率的な光増幅が可能になる。 The mirror 4 is a folding mirror that is installed so as to reflect the light that has passed through the discharge region and guide it again into the same discharge region. The mirror 5 is a folding mirror installed so as to reflect the light reflected by the mirror 4 and guide it again into the same discharge region. Accordingly, the laser light passes through the discharge region three times in the order of the optical path from the window member 2 to the mirror 4, the optical path from the mirror 4 to the mirror 5, and the optical path from the mirror 5 to the window member 3, for a total of three times. It will be amplified. Furthermore, by increasing the number of folding mirrors, the number of passes through the discharge region is also increased, and more efficient light amplification is possible.
　このように同一の放電領域にレーザ光を複数回通過させることにより、高い増幅利得が得られる。利得Ｇは、利得Ｇ＝出射光パワーＰｏ／入射光パワーＰｉで定義される。このとき、利得Ｇ≧ｅｘｐ［ｇ０×Ｌ］の関係が成立する。ここで、ｇ０は単位長さあたり小信号利得であり、Ｌは励起媒質の長手方向の幾何学的長さ、即ち、放電領域の長手方向の長さである。 Thus, a high amplification gain can be obtained by passing the laser beam through the same discharge region a plurality of times. The gain G is defined as gain G = emitted light power Po / incident light power Pi. At this time, the relationship of gain G ≧ exp [g 0 × L] is established. Here, g 0 is a small signal gain per unit length, and L is a geometric length in the longitudinal direction of the excitation medium, that is, a length in the longitudinal direction of the discharge region.
　同一の放電領域にレーザ光を１回だけ通過させるように構成されたガスレーザ増幅器においては、レーザ光の利得は小信号時の利得であるｅｘｐ［ｇ０×Ｌ］を上回ることはない（例えば、W. Rigrod, Journal of Applied Physics Vol.34 No.9(1963年) p2602を参照。小信号および小信号利得とは、入力が限りなく０に近い微小入力の条件を指す）。 In the gas laser amplifier configured to pass the laser beam only once through the same discharge region, the gain of the laser beam does not exceed exp [g 0 × L] which is a gain at the time of a small signal (for example, (See W. Rigrod, Journal of Applied Physics Vol. 34 No. 9 (1963) p2602. Small signal and small signal gain refer to the condition of a minute input whose input is nearly zero).
　本実施形態において、同一の放電領域にレーザ光が３回通過するように構成しているため、レーザ光が放電領域を通過する距離は、１回通過の場合と比べて３倍になる。例えば、ｇ０×Ｌ＝１．２となる励起条件のもとで、１０Ｗの入射レーザ光を増幅し、１５０Ｗの出射レーザ光を取り出す場合、利得Ｇは１５であり、ｅｘｐ［ｇ０×Ｌ］＝３．３を超えている。 In the present embodiment, since the laser light is configured to pass through the same discharge region three times, the distance that the laser light passes through the discharge region is three times that in the case of one pass. For example, when a 10 W incident laser beam is amplified and a 150 W outgoing laser beam is extracted under an excitation condition of g 0 × L = 1.2, the gain G is 15, and exp [g 0 × L ] = 3.3 is exceeded.
　また、上述のように、光学面が平面であるミラー４および５を互いに平行より約１ｍｒａｄずれた角度を成すように設置したことにより、簡便な構成で寄生発振を抑制する効果を奏している。 Also, as described above, the mirrors 4 and 5 having a flat optical surface are installed so as to form an angle shifted by about 1 mrad from the parallel to each other, thereby providing an effect of suppressing parasitic oscillation with a simple configuration.
　仮に、ミラー４，５が互いに平行に設置されていたとすると、ミラー４，５が共振器となって、放電電極１５，１６で決まる放電領域内で発生した自然放出光を種光としてレーザ発振が起こる。これを寄生発振という。寄生発振が発生すると、本来の発振領域以外においても励起エネルギーが消費されるため、レーザ増幅器の効率が低下してしまう。 Assuming that the mirrors 4 and 5 are installed in parallel to each other, the mirrors 4 and 5 serve as resonators, and laser oscillation is performed using spontaneously emitted light generated in the discharge region determined by the discharge electrodes 15 and 16 as seed light. Occur. This is called parasitic oscillation. When parasitic oscillation occurs, excitation energy is consumed even outside the original oscillation region, so that the efficiency of the laser amplifier is reduced.
　この対策として本実施形態では、ミラー４，５は、互いに平行より約１ｍｒａｄずれた角度を成すように設置しているため、ミラー４，５間を１往復する光路における回折損失が大きくなる。そのため、放電領域内で発生した自然放出光を種光とした寄生発振は起こらなくなり、簡便な構成で寄生発振を抑制できる。 As a countermeasure, in this embodiment, since the mirrors 4 and 5 are installed so as to form an angle shifted by about 1 mrad from the parallel, diffraction loss in the optical path that makes one round trip between the mirrors 4 and 5 increases. Therefore, parasitic oscillation using the spontaneous emission light generated in the discharge region as seed light does not occur, and parasitic oscillation can be suppressed with a simple configuration.
　ミラー４，５の設置角度は、２つのミラー面の角度（０度以上９０度未満）で定義する。ミラー面が平面でない構成、例えば凸面や凹面をした構成においても、上記のようにミラー面同士の角度を互いに微小角非平行に設置することによって、寄生発振を抑制できる。ここで平面でないミラー面の向きは、ミラーに当たったレーザビームの中心におけるミラー面の接面で定義できることは当業者にとっていうまでもない。 The installation angle of mirrors 4 and 5 is defined by the angle between two mirror surfaces (0 degree or more and less than 90 degrees). Even in a configuration in which the mirror surface is not flat, for example, a configuration having a convex surface or a concave surface, parasitic oscillation can be suppressed by setting the angles of the mirror surfaces to be non-parallel to each other by a minute angle as described above. It goes without saying for those skilled in the art that the orientation of the mirror surface which is not a plane can be defined by the contact surface of the mirror surface at the center of the laser beam hitting the mirror.
　また本実施形態において、入射レーザ光２１と出射レーザ光２２が同軸上に戻らないように構成することが好ましく、これにより簡便な構成で発振器への戻り光を低減する効果が得られる。 Further, in the present embodiment, it is preferable that the incident laser beam 21 and the emitted laser beam 22 are configured so as not to return on the same axis, thereby obtaining the effect of reducing the return light to the oscillator with a simple configuration.
　本実施形態において、２枚の折返しミラー４，５を用いた例を示しているが、３枚以上の折返しミラーを用いてもよく、この場合、レーザビームをｎ回目に折り返すミラーとｎ＋１回目に折り返すミラーとの２枚について、ミラーの数に応じた全ての自然数ｎについて平行から微小角度（目安として１ｍｒａｄ）を成すように設置すれば、同様の効果を奏する。 In the present embodiment, an example in which two folding mirrors 4 and 5 are used is shown, but three or more folding mirrors may be used. In this case, the laser beam is folded n times and n + 1 times. If the two mirrors that are folded back are installed so that all natural numbers n corresponding to the number of mirrors form a small angle from parallel (1 mrad as a guide), the same effect can be obtained.
　また、折返しミラーの微小角度は１ｍｒａｄ以上であってもよく、放電領域内で増幅されたレーザ光を再び同じ放電領域内を通過するようにできる角度であれば、同様の効果を奏する。 Further, the minute angle of the folding mirror may be 1 mrad or more, and the same effect can be obtained as long as the laser light amplified in the discharge region can pass through the same discharge region again.
実施の形態２．
　図２は、本発明の実施の形態２を示す斜視図である。本実施形態では、レーザ光が同一の放電領域を６回通過するように構成した例を説明する。 Embodiment 2. FIG.
FIG. 2 is a perspective view showing Embodiment 2 of the present invention. In the present embodiment, an example in which the laser beam is configured to pass through the same discharge region six times will be described.
　ガスレーザ増幅装置は、ＣＯ２等のレーザガスを封入するための筐体１と、筐体１内に設けられ、レーザガスを励起するための一対の放電電極１５，１６と、筐体１内に設けられ、レーザガスによって増幅されたレーザ光を反射するためのミラー４，５，６と、筐体１に設けられ、筐体内部と外部の間でレーザ光の通過を許容するためのウインドウ部材２などで構成される。 The gas laser amplifying apparatus is provided in the housing 1 for enclosing a laser gas such as CO 2 , a pair of discharge electrodes 15 and 16 for exciting the laser gas, and the housing 1. Mirrors 4, 5, 6 for reflecting the laser light amplified by the laser gas, and a window member 2 provided in the housing 1 for allowing the laser light to pass between the inside and the outside of the housing Composed.
　筐体１の一側面にはウインドウ部材２が設けられ、同じ側面にミラー５が取り付けられる。その対向側面には、ミラー４，６が取り付けられる。ミラー４，５，６は、光学面が平面である平面ミラーであることが好ましく、取り付け角度の微調節が可能なように、角度調整機構を介して筐体１の側面に取り付けられる。 A window member 2 is provided on one side of the housing 1, and a mirror 5 is attached to the same side. Mirrors 4 and 6 are attached to the opposite side surfaces. The mirrors 4, 5, and 6 are preferably flat mirrors having a flat optical surface, and are attached to the side surface of the housing 1 via an angle adjustment mechanism so that the attachment angle can be finely adjusted.
　ミラー４，５は、互いに非平行に設置されており、ミラー４の光学面の法線とミラー５の光学面の法線が、例えば、約１ｍｒａｄの角度を成すように設置される。ミラー５，６も互いに非平行に設置されており、ミラー５の光学面の法線とミラー６の光学面の法線が、例えば、約１０ｍｒａｄの角度を成すように設置される。 The mirrors 4 and 5 are installed non-parallel to each other, and are set so that the normal of the optical surface of the mirror 4 and the normal of the optical surface of the mirror 5 form an angle of about 1 mrad, for example. The mirrors 5 and 6 are also installed non-parallel to each other, and are set so that the normal of the optical surface of the mirror 5 and the normal of the optical surface of the mirror 6 form an angle of about 10 mrad, for example.
　放電電極１５，１６は、電極支持部材であるセラミック板１１，１２にメタライズされた電極として構成される。図３に示したように、放電領域１９は、放電電極１５，１６に挟まれた直方体の領域として定義される。放電電極１５，１６間に交流電圧を印加すると、放電電極１５と放電電極１６の間で放電が生じ、これによりレーザガスが励起され、その結果、放電領域１９を通過するレーザ光が増幅される。 The discharge electrodes 15 and 16 are configured as electrodes metallized on the ceramic plates 11 and 12 which are electrode support members. As shown in FIG. 3, the discharge region 19 is defined as a rectangular parallelepiped region sandwiched between the discharge electrodes 15 and 16. When an AC voltage is applied between the discharge electrodes 15 and 16, a discharge is generated between the discharge electrode 15 and the discharge electrode 16, thereby exciting the laser gas, and as a result, the laser light passing through the discharge region 19 is amplified.
　外部のレーザ発振器またはレーザ増幅器からのレーザ光がウインドウ部材２を通過し、入射レーザ光２１としてガスレーザ増幅装置に入射すると、ミラー４→ミラー５→ミラー６→ミラー５→ミラー４の順で反射し、再びウインドウ部材２を通過すると、最終的に出射レーザ光２２として出射される。 When laser light from an external laser oscillator or laser amplifier passes through the window member 2 and enters the gas laser amplifier as incident laser light 21, it is reflected in the order of mirror 4 → mirror 5 → mirror 6 → mirror 5 → mirror 4. When the light passes through the window member 2 again, it is finally emitted as emitted laser light 22.
　ミラー４は、放電領域内を通過した光を反射させて、再び同じ放電領域内へ導くように設置された折り返しミラーである。ミラー５は、ミラー４によって折り返された光を反射させて、再び同じ放電領域内へ導くように設置された折り返しミラーである。ミラー６は、ミラー５によって折り返された光を反射させて、再び同じ放電領域内へ導くように設置された折り返しミラーである。従って、レーザ光は、ウインドウ部材２からミラー４へ向かう光路、ミラー４からミラー５へ向かう光路、ミラー５からミラー６へ向かう光路、ミラー６からミラー５へ向かう光路、ミラー５からミラー４へ向かう光路、ミラー４からウインドウ部材３へ向かう光路の順に放電領域を６回通過するようになり、計６回増幅されることになる。さらに、折り返しミラーを増やすことによって、放電領域の通過回数も増加して、より効率的な光増幅が可能になる。 The mirror 4 is a folding mirror that is installed so as to reflect the light that has passed through the discharge region and guide it again into the same discharge region. The mirror 5 is a folding mirror installed so as to reflect the light reflected by the mirror 4 and guide it again into the same discharge region. The mirror 6 is a folding mirror installed so as to reflect the light reflected by the mirror 5 and guide it again into the same discharge region. Therefore, the laser light travels from the window member 2 to the mirror 4, from the mirror 4 to the mirror 5, from the mirror 5 to the mirror 6, from the mirror 6 to the mirror 5, and from the mirror 5 to the mirror 4. The discharge region passes through the discharge path six times in the order of the optical path and the optical path from the mirror 4 to the window member 3, and is amplified six times in total. Furthermore, by increasing the number of folding mirrors, the number of passes through the discharge region is also increased, and more efficient light amplification is possible.
　増幅利得に関して、実施の形態１と同様に、利得Ｇ＝出射光パワーＰｏ／入射光パワーＰｉ≧ｅｘｐ［ｇ０×Ｌ］の関係が成立する。本実施形態において、同一の放電領域にレーザ光が６回通過するように構成しているため、レーザ光が放電領域を通過する距離は、１回通過の場合と比べて６倍になる。例えば、ｇ０×Ｌ＝１．２となる励起条件のもとで、１０Ｗの入射レーザ光を増幅し、１ｋＷの出射レーザ光を取り出す場合、利得Ｇは１００であり、ｅｘｐ［ｇ０×Ｌ］＝３．３を超えている。 As with the first embodiment, the relationship of gain G = emitted light power Po / incident light power Pi ≧ exp [g 0 × L] is established for the amplification gain. In the present embodiment, since the laser beam is configured to pass through the same discharge region six times, the distance that the laser beam passes through the discharge region is six times that in the case where the laser beam passes once. For example, when 10 W of incident laser light is amplified and 1 kW of outgoing laser light is extracted under an excitation condition of g 0 × L = 1.2, the gain G is 100, and exp [g 0 × L ] = 3.3 is exceeded.
　また、上述のように、光学面が平面であるミラー４，５，６を互いに平行より約１ｍｒａｄずれた角度を持つように設置したことより、簡便な構成で寄生発振を抑制する効果を奏している。 In addition, as described above, the mirrors 4, 5 and 6 whose optical surfaces are flat are installed so as to have an angle shifted by about 1 mrad from the parallel, thereby providing an effect of suppressing parasitic oscillation with a simple configuration. Yes.
　仮に、ミラー４，５，６のうちいずれか２枚のミラーが互いに平行に設置されていたとすると、これらの平行ミラー同士が共振器となって、放電領域内で発生した自然放出光を種光として寄生発振が起こる。寄生発振が発生すると、本来の発振領域以外においても励起エネルギーが消費されるため、レーザ増幅器の効率が低下してしまう。 If any two of the mirrors 4, 5, and 6 are installed in parallel to each other, these parallel mirrors become resonators, and the spontaneously emitted light generated in the discharge region is used as seed light. As a result, parasitic oscillation occurs. When parasitic oscillation occurs, excitation energy is consumed even outside the original oscillation region, so that the efficiency of the laser amplifier is reduced.
　この対策として本実施形態では、上述のように、ミラー４，５は互いに平行より約１ｍｒａｄずれた角度を成し、ミラー５，６は互いに平行より約１０ｍｒａｄずれた角度を成すように設置しているため、ミラー４，５間を１往復する光路、ミラー５，６間を１往復する光路、およびミラー４，５，６間を１往復する光路における回折損失が大きくなる。そのため、放電領域内で発生した自然放出光を種光とした寄生発振は起こらなくなり、簡便な構成で寄生発振を抑制できる。 As a countermeasure, in the present embodiment, as described above, the mirrors 4 and 5 are installed so as to form an angle shifted by about 1 mrad from the parallel, and the mirrors 5 and 6 are installed so as to form an angle shifted by about 10 mrad from the parallel. Therefore, the diffraction loss in the optical path that makes one round trip between the mirrors 4 and 5, the optical path that makes one round trip between the mirrors 5 and 6, and the optical path that makes one round trip between the mirrors 4, 5, and 6 increases. Therefore, parasitic oscillation using the spontaneous emission light generated in the discharge region as seed light does not occur, and parasitic oscillation can be suppressed with a simple configuration.
　また、入射レーザ光２１の光軸と出射レーザ光２２の光軸が同軸上にならないように、入射レーザ光２１をミラー６の光学面の法線に対して、例えば、約１０ｍｒａｄの角度で斜め入射することにより、簡便な構成で発振器への戻り光を抑制できる。 Further, the incident laser beam 21 is inclined at an angle of, for example, about 10 mrad with respect to the normal of the optical surface of the mirror 6 so that the optical axis of the incident laser beam 21 and the optical axis of the emitted laser beam 22 are not coaxial. By making the light incident, return light to the oscillator can be suppressed with a simple configuration.
　本実施形態において、１枚のウインドウ部材２を入射レーザ光２１および出射レーザ光２２が通過する構成を示しているが、入射レーザ光２１が通過するウインドウ部材と、出射レーザ光２２が通過するウインドウ部材とを別個に設けても同様の効果を奏する。 In the present embodiment, the configuration in which the incident laser beam 21 and the emitted laser beam 22 pass through one window member 2 is shown. However, the window member through which the incident laser beam 21 passes and the window through which the emitted laser beam 22 passes. Even if the member is provided separately, the same effect can be obtained.
　なお、実施の形態１～２では、一対の放電電極１５，１６を配置した例を示しているが、複数対の放電電極が光路に沿って並んでいる構成であっても、同様の効果を奏する。 In the first and second embodiments, an example in which a pair of discharge electrodes 15 and 16 are arranged is shown, but the same effect can be obtained even in a configuration in which a plurality of pairs of discharge electrodes are arranged along the optical path. Play.
　また、実施の形態１～２では、放電電極１５，１６として、セラミック板１１，１２にメタライズされた電極を用いた例を示したが、放電電極１５，１６を他の方法で筐体１に固定しても同様の効果を奏する。 In the first and second embodiments, an example in which electrodes metalized on the ceramic plates 11 and 12 are used as the discharge electrodes 15 and 16 is shown. However, the discharge electrodes 15 and 16 are attached to the casing 1 by other methods. Even if fixed, the same effect can be obtained.
　また、実施の形態１～２では、レーザ媒質としてＣＯ２を用いた例を示しているが、エキシマレーザ等、他のレーザ媒質であっても同様の効果を奏する。 In the first and second embodiments, CO 2 is used as the laser medium. However, the same effect can be obtained with another laser medium such as an excimer laser.
　また、実施の形態１～２では、交流放電を用いてレーザガスを励起する例を示しているが、直流電圧による放電励起、光による励起など、他の励起方式を用いても同様の効果を奏する。 In the first and second embodiments, an example in which laser gas is excited using AC discharge is shown, but the same effect can be obtained by using other excitation methods such as discharge excitation by DC voltage and excitation by light. .
実施の形態３．
　図４は、本発明の実施の形態３を示す斜視図である。ここでは、本発明に係るガスレーザ増幅装置の光軸調整方法を説明する。以下、実施の形態１に係るガスレーザ増幅装置を例として説明するが、実施の形態２に係るガスレーザ増幅装置にも同様に適用できる。 Embodiment 3 FIG.
FIG. 4 is a perspective view showing Embodiment 3 of the present invention. Here, the optical axis adjustment method of the gas laser amplifier according to the present invention will be described. Hereinafter, the gas laser amplifying apparatus according to the first embodiment will be described as an example, but the same can be applied to the gas laser amplifying apparatus according to the second embodiment.
　筐体１の外側には、入射レーザ光の光軸と交差するように、レーザ吸収機構としてダンパ４２が設置され、一方、出射レーザ光の光軸と交差するように、例えば、サーモパイル型ディテクタなどのパワー検出器４１が設置される。 A damper 42 is installed as a laser absorption mechanism on the outside of the housing 1 so as to intersect with the optical axis of the incident laser light, and on the other hand, for example, a thermopile detector or the like so as to intersect with the optical axis of the emitted laser light. The power detector 41 is installed.
　こうした構成において、ダンパ４２およびパワー検出器４１を取り除き、ミラー４，５の相対角度が約１ｍｒａｄの角度を成すように光軸を調整すると、実施の形態１と同じガスレーザ増幅装置となる。 In such a configuration, when the damper 42 and the power detector 41 are removed and the optical axis is adjusted so that the relative angle of the mirrors 4 and 5 forms an angle of about 1 mrad, the same gas laser amplifying apparatus as in the first embodiment is obtained.
　最初に、入射レーザ光の光軸上に補助ミラー（不図示）等を設置することによって、外部光源からのガイド光（例えば、ヘリウムネオンレーザ光）を入射レーザ光の光軸に沿って導入する。このときガイド光がウインドウ部材２の中心を通過し、ミラー４の光学面中心に当たるように、ガイド光の光軸を調整する。 First, by installing an auxiliary mirror (not shown) or the like on the optical axis of the incident laser light, guide light (for example, helium neon laser light) from an external light source is introduced along the optical axis of the incident laser light. . At this time, the optical axis of the guide light is adjusted so that the guide light passes through the center of the window member 2 and hits the center of the optical surface of the mirror 4.
　次に、ミラー４の設置角度を調整し、ミラー４で反射されたガイド光がミラー５の光学面中心に当たるようにする。続いて、ミラー５の設置角度を調整し、ミラー５で反射されたガイド光がウインドウ部材３の中心を通過するようにする。その後、補助ミラーを除去してガイド光の導入を停止する。 Next, the installation angle of the mirror 4 is adjusted so that the guide light reflected by the mirror 4 strikes the center of the optical surface of the mirror 5. Subsequently, the installation angle of the mirror 5 is adjusted so that the guide light reflected by the mirror 5 passes through the center of the window member 3. Thereafter, the auxiliary mirror is removed and the introduction of the guide light is stopped.
　次に、放電電極１５，１６に対して交流電圧を印加し、放電電極１５，１６によって決まる放電領域でレーザガスが励起された状態とする。ここで、ミラー４，５が互いに平行に極めて近い角度θａ（例えば、１ｍｒａｄオーダーよりも小さい角度）をなしていれば、ミラー４，５間で寄生発振光２３が発生するようになる。寄生発振光２３の一部は、ミラー５で回折して回折光２４となってウインドウ部材３を通ってパワー検出器４１に到達し、さらにミラー４で回折して回折光２５となってウインドウ部材３を通ってダンパ４１に到達する。 Next, an AC voltage is applied to the discharge electrodes 15 and 16 so that the laser gas is excited in a discharge region determined by the discharge electrodes 15 and 16. Here, if the mirrors 4 and 5 form an angle θa that is extremely close to each other in parallel (for example, an angle smaller than 1 mrad order), the parasitic oscillation light 23 is generated between the mirrors 4 and 5. Part of the parasitic oscillation light 23 is diffracted by the mirror 5 to become diffracted light 24, passes through the window member 3, reaches the power detector 41, and further diffracted by the mirror 4 to become diffracted light 25. 3 to reach the damper 41.
　一方、ミラー４，５の相対角度が角度θａよりも大きい場合は、寄生発振が起こらず、パワー検出器４１では寄生発振光が検出されない。この場合、ミラー４及び／又はミラー５の設置角度を微調整することによって、ミラー４，５の相対角度が角度θａ以下となるようにミラー４，５の光軸を調整し、寄生発振が発生するアライメント状態とする。このときパワー検出器４１で検出される寄生発振パワーが最大となるように設定することによって、ミラー４，５が互いに完全に平行になるように調整できる。 On the other hand, when the relative angle of the mirrors 4 and 5 is larger than the angle θa, the parasitic oscillation does not occur, and the power detector 41 does not detect the parasitic oscillation light. In this case, by finely adjusting the installation angle of the mirror 4 and / or the mirror 5, the optical axes of the mirrors 4 and 5 are adjusted so that the relative angle of the mirrors 4 and 5 is equal to or smaller than the angle θa, and parasitic oscillation occurs. Alignment state to be performed. At this time, by setting the parasitic oscillation power detected by the power detector 41 to be maximum, the mirrors 4 and 5 can be adjusted to be completely parallel to each other.
　次に、最大パワーの状態からミラー４及び／又はミラー５の設置角度を意図的にずらして、ミラー４，５の相対角度を、例えば、約１ｍｒａｄに設定すると、寄生発振パワーが急激に低下する。このとき寄生発振パワーが最小となるように設定すれば、寄生発振を確実に防止できる。 Next, when the installation angle of the mirror 4 and / or the mirror 5 is intentionally shifted from the maximum power state and the relative angle of the mirrors 4 and 5 is set to about 1 mrad, for example, the parasitic oscillation power rapidly decreases. . At this time, if the parasitic oscillation power is set to be minimum, the parasitic oscillation can be surely prevented.
　図５は、ミラーの平行度と寄生発振の関係を示すグラフである。縦軸は、パワー検出器４１で検出された寄生発振パワー（リニア、任意単位）であり、横軸は、ミラー４，５の相対角度（ｍｒａｄ）である。ここで、寄生発振パワーが最大となるアライメント状態を原点（０ｍｒａｄ）としている。このグラフを見ると、ミラー４，５の相対角度を約１ｍｒａｄ以上に設定すれば、寄生発振パワーは最小になり、寄生発振が抑制されることが判る。 FIG. 5 is a graph showing the relationship between mirror parallelism and parasitic oscillation. The vertical axis represents the parasitic oscillation power (linear, arbitrary unit) detected by the power detector 41, and the horizontal axis represents the relative angle (mrad) of the mirrors 4 and 5. Here, the alignment state in which the parasitic oscillation power is maximized is defined as the origin (0 mrad). From this graph, it can be seen that if the relative angle of the mirrors 4 and 5 is set to about 1 mrad or more, the parasitic oscillation power is minimized and the parasitic oscillation is suppressed.
　こうした手法により、簡便な手順で寄生発振を抑制できるようにガスレーザ増幅装置の光軸調整を行うことができる。 By such a method, the optical axis of the gas laser amplifying apparatus can be adjusted so that parasitic oscillation can be suppressed with a simple procedure.
実施の形態４．
　図６は、本発明の実施の形態４を示す斜視図である。ここでは、本発明に係るガスレーザ増幅装置の光軸調整について説明する。以下、実施の形態１に係るガスレーザ増幅装置を例として説明するが、実施の形態２，３に係るガスレーザ増幅装置にも同様に適用できる。 Embodiment 4 FIG.
FIG. 6 is a perspective view showing Embodiment 4 of the present invention. Here, the optical axis adjustment of the gas laser amplifier according to the present invention will be described. Hereinafter, the gas laser amplifying apparatus according to the first embodiment will be described as an example, but the present invention can be similarly applied to the gas laser amplifying apparatus according to the second and third embodiments.
　筐体１内には、レーザ光の光路に沿って２枚の開口部材３１，３２が所定間隔、例えば、１ｍの間隔で互いに平行に設置される。開口部材３１は２つの開口３３，３４を有し、開口部材３２も２つの開口３５，３６を有する。これらの開口３３～３６は、レーザ光が通過する空間を機械的に制限する機能を有するものであり、筐体１内の光路の数が増加すると開口の数も増加する。 In the housing 1, two opening members 31, 32 are installed in parallel to each other at a predetermined interval, for example, 1 m along the optical path of the laser beam. The opening member 31 has two openings 33 and 34, and the opening member 32 also has two openings 35 and 36. These openings 33 to 36 have a function of mechanically limiting the space through which the laser light passes, and the number of openings increases as the number of optical paths in the housing 1 increases.
　筐体１の外側には、ガイド光（例えば、ヘリウムネオンレーザ光）２８を発生する光源５１が設置される。 A light source 51 that generates guide light (for example, helium neon laser light) 28 is installed outside the housing 1.
　図８は、開口部材３１，３２の形状の一例を示す斜視図である。開口部材３１と開口部材３２は、開口の位置を除いて同形である。開口部材３１の開口３３，３４の各中心は、開口部材３１の対称軸上に設けられている。一方、開口部材３２に対する開口３６の位置は、開口部材３１に対する開口３４の位置と同じであるが、開口部材３２に対する開口３５の位置は、開口部材３１に対する開口３５の位置よりも、例えば、２ｍｍ右側（図６のＡ方向の反対方向）にずらして設けられている。 FIG. 8 is a perspective view showing an example of the shape of the opening members 31 and 32. The opening member 31 and the opening member 32 have the same shape except for the position of the opening. The centers of the openings 33 and 34 of the opening member 31 are provided on the axis of symmetry of the opening member 31. On the other hand, the position of the opening 36 with respect to the opening member 32 is the same as the position of the opening 34 with respect to the opening member 31, but the position of the opening 35 with respect to the opening member 32 is, for example, 2 mm than the position of the opening 35 with respect to the opening member 31. They are shifted to the right (the direction opposite to the direction A in FIG. 6).
　図７は、開口部材３１の開口３３，３４、開口部材３２の開口３５，３６、ミラー４，５、およびウインドウ部材２，３の相対位置を図６のＡ方向から見た側面図である。開口部材３１に対する開口３５の中心は、図７の紙面から２ｍｍ手前に位置している。そのため、開口３３の中心と開口３５の中心とを結ぶ第１直線は、開口３４の中心と開口３６の中心とを結ぶ第２直線に対してねじれの位置になる。このときねじれ角は、２ｍｍ／１ｍ＝２ｍｒａｄに相当する。 FIG. 7 is a side view of the relative positions of the openings 33 and 34 of the opening member 31, the openings 35 and 36 of the opening member 32, the mirrors 4 and 5, and the window members 2 and 3 from the direction A in FIG. The center of the opening 35 with respect to the opening member 31 is located 2 mm before the paper surface of FIG. Therefore, the first straight line connecting the center of the opening 33 and the center of the opening 35 is a twisted position with respect to the second straight line connecting the center of the opening 34 and the center of the opening 36. At this time, the twist angle corresponds to 2 mm / 1 m = 2 mrad.
　次に、ガイド光２８を各ミラーの光軸に沿って導入する。そして、ガイド光２８が開口３４の中心、開口３６の中心、開口３３の中心、開口３５の中心を通るように２枚のミラー４，５の設置角度を調整すると、ミラー４，５の相対角度（ｍｒａｄ）は約１ｍｒａｄに設定される。 Next, guide light 28 is introduced along the optical axis of each mirror. When the installation angle of the two mirrors 4 and 5 is adjusted so that the guide light 28 passes through the center of the opening 34, the center of the opening 36, the center of the opening 33, and the center of the opening 35, the relative angle of the mirrors 4 and 5 (Mrad) is set to about 1 mrad.
　こうした手法により、簡便な手順で寄生発振を抑制できるようにガスレーザ増幅装置の光軸調整を行うことができる。 By such a method, the optical axis of the gas laser amplifying apparatus can be adjusted so that parasitic oscillation can be suppressed with a simple procedure.
　１　筐体、　２，３　ウインドウ部材、　４，５，６　ミラー、　１１，１２　セラミック板、　１５，１６　放電電極、　１９　放電領域、　２１　入射レーザ光、　２２　出射レーザ光、　２３　寄生発振光、　２４，２５　回折光、　２８　ガイド光、　３１，３２　開口部材、　３３，３４，３５，３６　開口、　４１　パワー検出器、　４２　ダンパ、　５１　光源。 1 housing, 2, 3 window member, 4, 5, 6 mirror, 11, 12 ceramic plate, 15, 16 discharge electrode, 19 discharge area, 21 incident laser light, 22 outgoing laser light, 23 parasitic oscillation light, 24, 25 diffracted light, 28 guide light, 31, 32 aperture member, 33, 34, 35, 36 aperture, 41 power detector, 42 damper, 51 light source.

Claims (7)

  1. 　レーザガスを封入するための筐体と、
    　筐体内に設けられ、レーザガスを励起するための一対の放電電極と、
    　筐体内に設けられ、レーザガスによって増幅されたレーザ光を反射するための少なくとも２枚のミラーと、
    　筐体に設けられ、筐体内部と外部の間でレーザ光の通過を許容するためのウインドウ部材とを備え、
    　第１のミラーは、前記放電電極のうちのある一対の放電電極によって決まる放電領域内を通過した光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
    　第２のミラーは、第１のミラーによって折り返された光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
    　第１および第２のミラーは、互いに非平行に設置されることを特徴とするガスレーザ増幅装置。     A housing for enclosing the laser gas;
    A pair of discharge electrodes provided in the housing for exciting the laser gas;
    At least two mirrors provided in the housing for reflecting the laser light amplified by the laser gas;
    A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing;
    The first mirror is a folding mirror that is disposed so as to reflect light that has passed through a discharge region determined by a certain pair of discharge electrodes of the discharge electrodes and to guide the light again into the discharge region;
    The second mirror is a folding mirror installed so as to reflect the light reflected by the first mirror and guide it again into the discharge region,
    The gas laser amplifying apparatus, wherein the first and second mirrors are installed non-parallel to each other.
  2. 　第１および第２のミラー面のなす角度は、第１および第２の２枚のミラーでの寄生発振をさせないような角度であることを特徴とする請求項１記載のガスレーザ増幅装置。 2. The gas laser amplifying apparatus according to claim 1, wherein the angle formed by the first and second mirror surfaces is an angle that does not cause parasitic oscillation in the first and second mirrors.
  3. 　第１および第２のミラー面のなす角度は、１ｍｒａｄ以上で９０度以下であることを特徴とする請求項１または２記載のガスレーザ増幅装置。 3. The gas laser amplifying apparatus according to claim 1, wherein an angle formed by the first and second mirror surfaces is 1 mrad or more and 90 degrees or less.
  4. 　レーザガスを封入するための筐体と、
    　筐体内に設けられ、レーザガスを励起するための一対の放電電極と、
    　筐体内に設けられ、レーザガスによって増幅されたレーザ光を反射するための少なくとも３枚のミラーと、
    　筐体に設けられ、筐体内部と外部の間でレーザ光の通過を許容するためのウインドウ部材とを備え、
    　第１のミラーは、前記放電電極のうちのある一対の放電電極によって決まる放電領域内を通過した光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
    　第２のミラーは、第１のミラーによって折り返された光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
    　第３のミラーは、第２のミラーによって折り返された光を反射させて、再び該放電領域内へ導くように設置された折り返しミラーであり、
    　第１、第２および第３のミラーは、互いに非平行に設置されることを特徴とするガスレーザ増幅装置。     A housing for enclosing the laser gas;
    A pair of discharge electrodes provided in the housing for exciting the laser gas;
    At least three mirrors provided in the housing for reflecting the laser light amplified by the laser gas;
    A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing;
    The first mirror is a folding mirror that is disposed so as to reflect light that has passed through a discharge region determined by a certain pair of discharge electrodes of the discharge electrodes and to guide the light again into the discharge region;
    The second mirror is a folding mirror installed so as to reflect the light reflected by the first mirror and guide it again into the discharge region,
    The third mirror is a folding mirror that is installed so as to reflect the light reflected by the second mirror and guide it back into the discharge region.
    The gas laser amplifier according to claim 1, wherein the first, second and third mirrors are installed non-parallel to each other.
  5. 　第１および第２のミラー面のなす角度は、第１および第２の２枚のミラーでの寄生発振をさせないような角度であり、
    　第２および第３のミラー面のなす角度は、第２および第３の２枚のミラーでの寄生発振をさせないような角度であることを特徴とする請求項４記載のガスレーザ増幅装置。     The angle formed by the first and second mirror surfaces is an angle that does not cause parasitic oscillations in the first and second mirrors,
    5. The gas laser amplifying apparatus according to claim 4, wherein the angle formed by the second and third mirror surfaces is an angle that does not cause parasitic oscillation in the second and third mirrors.
  6. 　第１および第２のミラー面のなす角度は、１ｍｒａｄ以上で９０度以下であり、
    　第２および第３のミラー面のなす角度は、１ｍｒａｄ以上で９０度以下であることを特徴とする請求項４または５記載のガスレーザ増幅装置。     The angle formed by the first and second mirror surfaces is 1 mrad or more and 90 degrees or less,
    6. The gas laser amplifying apparatus according to claim 4, wherein an angle formed by the second and third mirror surfaces is not less than 1 mrad and not more than 90 degrees.
  7. 　レーザガスを封入するための筐体と、
    　筐体内に設けられ、レーザガスを励起するための一対の放電電極と、
    　筐体内に設けられ、レーザガスによって増幅されたレーザ光を反射するための少なくとも２枚のミラーと、
    　筐体に設けられ、筐体内部と外部の間でレーザ光の通過を許容するためのウインドウ部材とを備え、
    　第１のミラー付近には、第１開口および第４開口を有する第１開口部材が配置され、
    　第２のミラー付近には、第２開口および第３開口を有する第２開口部材が配置され、
    　第１開口の中心と第２開口の中心とを結ぶ第１直線が、第３開口の中心と第４開口の中心とを結ぶ第２直線に対してねじれの位置にあり、
    　レーザ光は、第１開口、第２開口、第１のミラー、第２開口、第３開口、第２のミラー、第３開口、第４開口の順に通過することを特徴とするガスレーザ増幅装置。     A housing for enclosing the laser gas;
    A pair of discharge electrodes provided in the housing for exciting the laser gas;
    At least two mirrors provided in the housing for reflecting the laser light amplified by the laser gas;
    A window member that is provided in the housing and allows the passage of laser light between the inside and outside of the housing;
    A first opening member having a first opening and a fourth opening is disposed near the first mirror,
    A second opening member having a second opening and a third opening is disposed near the second mirror,
    The first straight line connecting the center of the first opening and the center of the second opening is in a position twisted with respect to the second straight line connecting the center of the third opening and the center of the fourth opening;
    The gas laser amplifier according to claim 1, wherein the laser beam passes in the order of the first opening, the second opening, the first mirror, the second opening, the third opening, the second mirror, the third opening, and the fourth opening.
PCT/JP2011/064013 2011-06-20 2011-06-20 Gas laser amplification device WO2012176252A1 (en)

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