Method for manufacturing optical module, method for manufacturing gas laser device, and jig for manufacturing optical module

Abstract

The invention provides a method for manufacturing an optical module, a method for manufacturing a gas laser device, and a jig for manufacturing an optical module. In the method of manufacturing an optical module, the optical module includes: an output coupling mirror that transmits a portion of a laser beam and reflects another portion of the laser beam; and a plane mirror including a plane reflection surface perpendicular to the surface of the output coupling mirror on the incident side of the laser light, the method for manufacturing the optical module having the steps of: disposing the first autocollimator such that the emitted light is vertically incident on the surface of the incident side; an optical element is disposed between a surface on the incidence side and the first autocollimator such that light emitted from the first autocollimator is vertically incident on a first reflection surface included in the optical element, the optical element including a second reflection surface that faces the surface on the incidence side and forms an angle of 45 DEG with the first reflection surface; a second auto-collimator is disposed so that the emitted light is reflected by a second reflection surface and is vertically incident on a surface on the incident side; the optical element is removed, and the plane mirror is disposed such that the light emitted from the second autocollimator is vertically incident on the reflection surface of the plane mirror.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing an optical module, a method for manufacturing a gas laser device, and a manufacturing jig for an optical module. Background Art

[0002] In recent years, in semiconductor exposure apparatuses, with the miniaturization and high integration of semiconductor integrated circuits, an improvement in resolution has been required. Therefore, the shortening of the wavelength of light emitted from an exposure light source has been developed. For example, as a gas laser device for exposure, a KrF excimer laser device that emits laser light with an output wavelength of approximately 248.0 nm and an ArF excimer laser device that emits laser light with an output wavelength of approximately 193.4 nm are used.

[0003] The spectral line width of the spontaneous oscillation light of a KrF excimer laser device and an ArF excimer laser device is relatively wide, being 350 pm to 400 pm. Therefore, when a projection lens is formed of a material that transmits ultraviolet light such as KrF and ArF lasers, chromatic aberration may sometimes occur. As a result, the resolution may be reduced. Therefore, it is necessary to narrow the spectral line width of the laser output from the gas laser device to a level where chromatic aberration can be ignored. Therefore, in the laser resonator of the gas laser device, in order to narrow the spectral line width, a line narrowing module (LNM) including a line narrowing element (etalon, grating, etc.) may sometimes be provided. Hereinafter, a gas laser device whose spectral line width has been narrowed will be referred to as a narrowband gas laser device.

[0004] Patent Document 1: Japanese Patent Laid-Open No. 08-118667

[0005] Patent Document 2: Japanese Patent No. 5589397 Specification

[0006] Patent Document 3: International Publication No. 2007 / 053335 Summary of the Invention

[0007] In a method of manufacturing an optical module according to an aspect of the present disclosure, the optical module includes: an output coupling mirror that transmits a part of the laser light and reflects another part of the laser light; and a flat mirror that includes a plane reflecting surface perpendicular to the surface on the incident side of the laser light of the output coupling mirror. The method of manufacturing the optical module includes the following steps: a first autocollimator arranging step of arranging the first autocollimator so that the first autocollimator receives the light reflected from the surface on the incident side of the light emitted from the first autocollimator and the light is incident perpendicularly on the surface on the incident side; an optical element arranging step of arranging an optical element between the surface on the incident side and the first autocollimator so that the first autocollimator receives the light reflected from a first reflecting surface as follows and the light is incident perpendicularly on the first reflecting surface, the first reflecting surface being a reflecting surface included in the optical element and opposed to the first autocollimator, and the optical element including a second reflecting surface that forms an angle of 45° with the first reflecting surface and is opposed to the surface on the incident side; a second autocollimator arranging step of arranging the second autocollimator so that the second autocollimator receives the light reflected successively from the second reflecting surface, the surface on the incident side, and the second reflecting surface of the light emitted from the second autocollimator and the light is incident perpendicularly on the surface on the incident side; and a first mirror arranging step of removing the optical element and arranging the flat mirror so that the second autocollimator receives the light reflected from the reflecting surface of the flat mirror of the light emitted from the second autocollimator and the light is incident perpendicularly on the reflecting surface.

[0008] In the manufacturing method of a gas laser device according to one aspect of the present disclosure, the gas laser device includes: a cavity device that amplifies laser light output from a laser oscillator; and an optical module that includes an output coupling mirror and a flat mirror. The output coupling mirror allows a part of the laser light emitted from the cavity device to pass through and reflects another part of the laser light emitted from the cavity device back to the cavity device. The flat mirror includes a plane reflecting surface perpendicular to the surface on the incident side of the laser of the output coupling mirror. Among them, the optical module manufactured by the following manufacturing method of the optical module is arranged such that the laser light emitted from the cavity device is perpendicularly incident on the surface on the incident side of the output coupling mirror. The manufacturing method of the optical module includes the following steps: a first autocollimator arranging step of arranging the first autocollimator such that the first autocollimator receives the light reflected from the surface on the incident side among the light emitted from the first autocollimator and the light is perpendicularly incident on the surface on the incident side; an optical element arranging step of arranging an optical element between the surface on the incident side and the first autocollimator such that the first autocollimator receives the light reflected from the following first reflecting surface among the light emitted from the first autocollimator and the light is perpendicularly incident on the first reflecting surface. The first reflecting surface is a reflecting surface included in the optical element and opposed to the first autocollimator, and the optical element includes a second reflecting surface that forms an angle of 45° with the first reflecting surface and is opposed to the surface on the incident side; a second autocollimator arranging step of arranging the second autocollimator such that the second autocollimator receives the light reflected successively from the second reflecting surface, the surface on the incident side, and the second reflecting surface among the light emitted from the second autocollimator and the light is perpendicularly incident on the surface on the incident side; and a first mirror arranging step of removing the optical element and arranging the flat mirror such that the second autocollimator receives the light reflected from the reflecting surface of the flat mirror among the light emitted from the second autocollimator and the light is perpendicularly incident on the reflecting surface.

[0009] In a manufacturing jig for an optical module according to one aspect of the present disclosure, the optical module includes: an output coupling mirror that allows a part of the laser light to pass through and reflects another part of the laser light; and a flat mirror that includes a plane reflecting surface perpendicular to the surface on the incident side of the laser of the output coupling mirror. Among them, the manufacturing jig for the optical module includes: a first autocollimator arranged such that the light emitted from the first autocollimator is perpendicularly incident on the surface on the incident side of the output coupling mirror; an optical element that includes a first reflecting surface opposed to the first autocollimator and a second reflecting surface that forms an angle of 45° with the first reflecting surface and is opposed to the surface on the incident side, and the optical element is arranged between the surface on the incident side and the first autocollimator such that the light emitted from the first autocollimator is perpendicularly incident on the first reflecting surface; and a second autocollimator arranged such that the light emitted from the second autocollimator is reflected by the second reflecting surface and perpendicularly incident on the surface on the incident side. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Hereinafter, several embodiments of the present disclosure will be described as examples with reference to the accompanying drawings.

[0011] Figure 1 It is a schematic diagram showing a schematic overall structure example of a manufacturing apparatus for an electronic device.

[0012] Figure 2 It is a schematic diagram showing a schematic overall structure example of a gas laser device of a comparative example.

[0013] Figure 3 It is a schematic diagram of an amplifier of a comparative example observed from the direction in which a pair of electrodes face each other.

[0014] Figure 4 It is a schematic diagram showing a schematic structure example of a beam expander of a comparative example.

[0015] Figure 5 It is a perspective view showing a convex mirror, a concave mirror, and a plane mirror of a comparative example.

[0016] Figure 6 is in the same manner as Figure 4 A schematic diagram showing a schematic structure example of the beam expander of Embodiment 1.

[0017] Figure 7 It is a diagram showing an example of a flowchart of a manufacturing method of the beam expander of Embodiment 1.

[0018] Figure 8 It is a diagram showing a situation of an output coupling mirror arranging step.

[0019] Figure 9 It is a diagram showing a situation of a first autocollimator arranging step.

[0020] Figure 10 It is a diagram showing a situation of an optical element arranging step.

[0021] Figure 11 is observed from a direction perpendicular to the arranging surface Figure 10 A diagram showing a situation of the optical element arranging step shown.

[0022] Figure 12 It is a diagram showing a situation of a second autocollimator arranging step.

[0023] Figure 13 It is a diagram showing a situation of a first mirror arranging step.

[0024] Figure 14 It is a diagram showing a situation of a wavefront sensor arranging step.

[0025] Figure 15 It is a diagram showing a situation of a pinhole plate arranging step.

[0026] Figure 16 is a diagram showing a case of a reference light source configuration process.

[0027] Figure 17 is a diagram showing a case of arranging a concave mirror.

[0028] Figure 18 is a diagram showing a case of arranging a convex mirror.

[0029] Figure 19 is a diagram of a part of the case of arranging the convex mirror shown Figure 18 when observing along the arrow A in Figure 18 the figure. DETAILED DESCRIPTION

[0030] 1. Description of a manufacturing apparatus for an electronic device used in an exposure process of an electronic device

[0031] 2. Description of a gas laser device of a comparative example

[0032] 2.1 Structure

[0033] 2.2 Operation

[0034] 2.3 Manufacturing method of an expander

[0035] 2.4 Problems

[0036] 3. Description of an expander and a manufacturing method of an expander according to Embodiment 1

[0037] 3.1 Structure

[0038] 3.2 Manufacturing method of an expander

[0039] 3.3 Function / Effect

[0040] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and operations described in each embodiment are not necessarily all essential to the structures and operations of the present disclosure. In addition, the same reference numerals are assigned to the same structural elements and repeated descriptions are omitted.

[0041] 1. Description of a manufacturing apparatus for an electronic device used in an exposure process of an electronic device

[0042] Figure 1 is a schematic diagram showing a schematic overall structure example of a manufacturing apparatus for an electronic device used in an exposure process of an electronic device. As Figure 1As shown, the manufacturing apparatus used in the exposure process includes a gas laser apparatus 100 and an exposure apparatus 200. The exposure apparatus 200 includes an illumination optical system 210 and a projection optical system 220. The illumination optical system 210 includes a plurality of mirrors 211, 212, and 213. The illumination optical system 210 illuminates the mask pattern on the mask stage RT with the laser light incident from the gas laser apparatus 100. The projection optical system 220 reduces and projects the laser light passing through the mask and forms an image on a workpiece (not shown) disposed on the workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a photoresist. The exposure apparatus 200 moves the mask stage RT and the workpiece stage WT synchronously and parallelly, thereby exposing the workpiece with the laser light reflecting the mask pattern. By performing the exposure process as described above, a device pattern is transferred onto the semiconductor wafer, and a semiconductor device as an electronic device can be manufactured.

[0043] 2. Description of the gas laser apparatus of the comparative example

[0044] 2.1 Structure

[0045] The gas laser apparatus of the comparative example will be described. In addition, the comparative example of the present disclosure is a method that the applicant recognizes as known only to the applicant and is not a publicly known example admitted by the applicant himself.

[0046] Figure 2 FIG. is a schematic diagram showing a schematic structural example of the entire gas laser apparatus 100 of this example. The gas laser apparatus 100 is, for example, an ArF excimer laser apparatus using a mixed gas containing argon (Ar), fluorine (F2), and neon (Ne). The gas laser apparatus 100 outputs laser light having a center wavelength of approximately 193.4 nm. In addition, the gas laser apparatus 100 may be a gas laser apparatus other than an ArF excimer laser apparatus. For example, it may be a KrF excimer laser apparatus using a mixed gas containing krypton (Kr), F2, and Ne. In this case, the gas laser apparatus 100 emits laser light having a center wavelength of approximately 248.0 nm. A mixed gas containing Ar, F2, and Ne as a laser medium and a mixed gas containing Kr, F2, and Ne as a laser medium are sometimes referred to as laser gas. In addition, in the mixed gases used in the ArF excimer laser apparatus and the KrF excimer laser apparatus, helium (He) may be used instead of Ne.

[0047] The gas laser apparatus 100 of this example mainly includes a housing 110, a laser oscillator 130 as a master oscillator disposed in the internal space of the housing 110, an optical transmission unit 141, an amplifier 160 as a power oscillator, a detection unit 153, a display unit 180, a processor 190, a laser gas exhaust device 701, and a laser gas supply device 703.

[0048] The laser oscillator 130 includes a cavity device CH1, a charger 41, a pulse power module 43, a narrowbanding module 60, and an output coupling mirror 70 as main structures.

[0049] In Figure 2 it, the internal structure of the cavity device CH1 observed from a direction substantially perpendicular to the traveling direction of the laser is shown. The cavity device CH1 has a housing 30, a pair of windows 31a, 31b, a pair of electrodes 32a, 32b, an insulating portion 33, a feedthrough hole 34, and an electrode holder portion 36 as main structures.

[0050] For the housing 30, the above-mentioned laser gas is supplied from the laser gas supply device 703 into the internal space of the housing 30 via a pipe, and the housing 30 seals the laser gas into the internal space. The internal space is a space where light is generated by the excitation of the laser medium in the laser gas. This light travels toward the windows 31a, 31b.

[0051] The window 31a is disposed on the front wall surface of the housing 30 in the traveling direction of the laser from the gas laser device 100 toward the exposure device 200, and the window 31b is disposed on the rear wall surface of the housing 30 in this traveling direction. The windows 31a, 31b are calcium fluoride substrates, and the surfaces of the windows 31a, 31b on the inner side and the outer side of the housing 30 are flat. In addition, the windows 31a, 31b are not limited to calcium fluoride substrates as long as they can transmit the laser.

[0052] The electrodes 32a, 32b are disposed opposite to each other in the internal space of the housing 30, and the length direction of the electrodes 32a, 32b is along the traveling direction of the light generated by the high voltage applied between the electrodes 32a and 32b. The space between the electrodes 32a and 32b in the housing 30 is between the windows 31a and 31b. The electrodes 32a, 32b are discharge electrodes for exciting the laser medium by glow discharge. In this example, the electrode 32a is the cathode and the electrode 32b is the anode.

[0053] The electrode 32a is supported by the insulating portion 33. The insulating portion 33 closes the opening formed in the housing 30. The insulating portion 33 includes an insulator. In addition, a feedthrough hole 34 made of a conductive member is disposed in the insulating portion 33. The feedthrough hole 34 applies the voltage supplied from the pulse power module 43 to the electrode 32a. The electrode 32b is supported by the electrode holder portion 36 and is electrically connected to the electrode holder portion 36.

[0054] The charger 41 is a DC power supply device that charges a capacitor (not shown) disposed inside the pulse power module 43 with a specified voltage. The charger 41 is arranged outside the housing 30 and is connected to the pulse power module 43. The pulse power module 43 includes a switch (not shown) controlled by the processor 190. The pulse power module 43 is a voltage application circuit that boosts the voltage applied from the charger 41 to generate a pulsed high voltage when the switch changes from off to on by this control, and applies this high voltage to the electrodes 32a and 32b. When the high voltage is applied, a discharge occurs between the electrode 32a and the electrode 32b. By the energy of this discharge, the laser medium inside the housing 30 is excited. When the excited laser gas transitions to the ground state, light is emitted, and the emitted light exits the housing 30 through the windows 31a and 31b. The windows 31a and 31b are inclined at the Brewster angle with respect to the traveling direction of the laser to suppress the reflection of the P-polarized light of the laser. In this example, they are inclined with respect to the direction perpendicular to the traveling direction of the laser and the facing direction of the electrodes 32a and 32b. Therefore, the laser emitted from the cavity device CH1 contains the first linearly polarized light whose polarization direction is perpendicular to the facing direction of the electrodes 32a and 32b, and in the laser, the linearly polarized light whose polarization direction is different from the polarization direction of the first linearly polarized light is reduced. That is, the windows 31a and 31b also serve as polarizing plates that are inclined with respect to the polarization direction of the first linearly polarized light and reduce the linearly polarized light in the laser whose polarization direction is different from the polarization direction of the first linearly polarized light.

[0055] The narrowbanding module 60 includes a housing 65, a prism 61, a grating 63, and a rotary stage (not shown) disposed in the internal space of the housing 65. An opening is formed in the housing 65, and the housing 65 is connected to the rear side of the housing 30 via the opening.

[0056] The prism 61 expands the beam width of the light emitted from the window 31b and makes the light incident on the grating 63. In addition, the prism 61 narrows the beam width of the reflected light from the grating 63 and makes the light return to the internal space of the housing 30 via the window 31b. The prism 61 is supported by the rotary stage and rotates by the rotary stage. By rotating the prism 61, the incident angle of the light with respect to the grating 63 is changed. Therefore, by rotating the prism 61, the wavelength of the light that returns from the grating 63 to the housing 30 via the prism 61 can be selected. In Figure 2 which, an example in which one prism 61 is arranged is shown, however, two or more prisms may be arranged.

[0057] The surface of the grating 63 is made of a material with high reflectivity, and a plurality of grooves are provided on the surface at predetermined intervals. The grating 63 is a dispersive optical element. The cross-sectional shape of each groove is, for example, a right triangle. The light incident on the grating 63 from the prism 61 is reflected by these grooves and diffracted in a direction corresponding to the wavelength of the light. The grating 63 is configured in a Littrow manner so that the incident angle of the light incident on the grating 63 from the prism 61 is consistent with the diffraction angle of the diffracted light of the desired wavelength. Thus, the light of the desired wavelength is returned to the housing 30 via the prism 61.

[0058] The output coupling mirror 70 faces the window 31a, transmits part of the laser light emitted from the window 31a, and reflects the other part to return to the inner space of the housing 30 through the window 31a. The output coupling mirror 70 is fixed to a holder (not shown) and is arranged in the inner space of the housing 110.

[0059] A Fabry-Perot type resonator is formed by the grating 63 and the output coupling mirror 70 provided via the housing 30, and the housing 30 is disposed on the optical path of the resonator. Therefore, the resonator resonates light between both sides via the cavity device CH1.

[0060] The optical transmission unit 141 includes high reflective mirrors 141b and 141c as main structures. The high reflective mirrors 141b and 141c are respectively fixed to a holder (not shown) in a state where their respective inclination angles are adjusted, and are arranged in the internal space of the housing 110. The high reflective mirrors 141b and 141c reflect the laser light highly. The high reflective mirrors 141b and 141c are arranged on the optical path of the laser light from the output coupling mirror 70. The laser light is reflected by the high reflective mirrors 141b and 141c and travels toward the rear mirror 371 of the amplifier 160. At least a portion of the laser light passes through the rear mirror 371.

[0061] The amplifier 160 amplifies the energy of the laser output from the laser oscillator 130. The basic structure of the amplifier 160 is substantially the same as that of the laser oscillator 130. In order to distinguish the structural elements of the amplifier 160 from those of the laser oscillator 130, the cavity device, housing, pair of windows, pair of electrodes, insulating portion, feedthrough hole, electrode holder portion, charger, pulse power module, and output coupling mirror of the amplifier 160 are designated as the cavity device CH3, housing 330, pair of windows 331a, 331b, pair of electrodes 332a, 332b, insulating portion 333, feedthrough hole 334, electrode holder portion 336, charger 341, pulse power module 343, and output coupling mirror 370 for description. The electrodes 332a, 332b generate a discharge for amplifying the laser from the laser oscillator 130. The direction in which the electrodes 332a, 332b face each other is perpendicular to the changing direction of the first linearly polarized light in the laser from the laser oscillator 130. The windows 331a, 331b are inclined with respect to the polarization direction of the first linearly polarized light so that the first linearly polarized light in the laser is incident as P-polarized light and the incident angle θ of the laser becomes the Brewster angle. Therefore, the laser emitted from the cavity device CH3 contains the first linearly polarized light, and the linearly polarized light in the laser having a polarization direction different from the polarization direction of the first linearly polarized light is reduced. That is, like the windows 31a, 31b, the windows 331a, 331b also serve as polarizers that are inclined with respect to the polarization direction of the first linearly polarized light and reduce the linearly polarized light in the laser having a polarization direction different from the polarization direction of the first linearly polarized light. The pulse power module 343 is a voltage application circuit like the pulse power module 43.

[0062] In addition, the main difference between the amplifier 160 and the laser oscillator 130 is that the amplifier 160 does not have the narrowbanding module 60 and has a rear mirror 371 and a beam expander 400 as an optical module.

[0063] Figure 3 It is a schematic diagram of the amplifier 160 in this example as observed from the direction in which the pair of electrodes 332a, 332b face each other. In Figure 3 it, the internal structure of the cavity device CH3 is shown, and the polarization direction of the first linearly polarized light is indicated by a solid arrow.

[0064] The rear mirror 371 is disposed between the high-reflection mirror 141c and the window 331b, facing them respectively. The rear mirror 371 allows a part of the laser light from the laser oscillator 130 to pass through and go to the space between the electrodes 332a and 332b, and reflects a part of the laser light amplified between the electrodes 332a and 332b toward the space between the electrodes 332a and 332b. The rear mirror 371 is mounted on the cavity plate 511 on the window 331b side of the pair of cavity plates 511 and 512, and the pair of cavity plates 511 and 512 are configured to sandwich the cavity device CH3 in the longitudinal direction of the electrodes 332a and 332b. A through hole for the laser light from the laser oscillator 130 to pass through is provided in the cavity plate 511. The pair of cavity plates 511 and 512 are connected to a cavity frame 513 extending in a direction parallel to the longitudinal direction of the electrodes 332a and 332b around the cavity device CH3. In addition, in Figure 2 the description of the cavity plates 511 and 512 and the cavity frame 513 is omitted.

[0065] The output coupling mirror 370 is disposed on the side opposite to the rear mirror 371 side with respect to the cavity device CH3, and the beam expander 400 is disposed between the cavity device CH3 and the output coupling mirror 370.

[0066] Figure 4 is a schematic diagram showing a schematic structural example of the beam expander 400 of this example, and is a schematic diagram of the beam expander 400 observed along the polarization direction of the first linearly polarized light. Therefore, Figure 4 the direction perpendicular to the paper surface in

[0067] is the polarization direction of the first linearly polarized light. Figure 3 As Figure 4 shown, the beam expander 400 of this example includes a convex mirror 410, a concave mirror 420, a flat mirror 430, and a holding portion 470.

[0068] Figure 5 is a perspective view showing the convex mirror 410, the concave mirror 420, and the flat mirror 430 of this example. In Figure 5In this case, the polarization direction of the first linearly polarized light is indicated by an arrow of a solid line. The convex mirror 410 is a plate-shaped component whose main surface is a reflecting surface 411 for reflecting light. The concave mirror 420 is a plate-shaped component whose main surface is a reflecting surface 421 for reflecting light. The plane mirror 430 is a plate-shaped component whose main surface is a reflecting surface 431 for reflecting light, and the reflecting surface 431 is a plane. The convex mirror 410 reflects the laser from the cavity device CH3 to the plane mirror 430 in such a manner as to expand the beam width of the laser. The plane mirror 430 reflects the laser reflected by the convex mirror 410 to the concave mirror 420. The concave mirror 420 reflects the laser to the output coupler mirror 370 in such a manner as to collimate the expanded beam width of the laser reflected by the plane mirror 430 to be fixed. In addition, the concave mirror 420 reflects the laser from the output coupler mirror 370 to the plane mirror 430 in such a manner as to reduce the beam width of the laser. The plane mirror 430 reflects the laser reflected by the concave mirror 420 to the convex mirror 410. The convex mirror 410 reflects the laser to the cavity device CH3 in such a manner as to collimate the reduced beam width of the laser reflected by the plane mirror 430 to be fixed, and the laser returns to the internal space of the housing 330 via the window 331a.

[0069] In this example, the convex mirror 410 is a convex cylindrical mirror, and the shape of the convex mirror 410 when observing the reflecting surface 411 from the front is a rectangle that is longer in the direction parallel to the focal line 412 of the convex mirror 410. The shape of the reflecting surface 411 in the cross-section perpendicular to the focal line 412 is an arc, but this shape is not limited, and for example, it may also be a parabola. In addition, the concave mirror 420 is a concave cylindrical mirror, and the shape of the concave mirror 420 when observing the reflecting surface 421 from the front is a rectangle that is longer in the direction parallel to the focal line 422 of the concave mirror 420. The shape of the reflecting surface 421 in the cross-section perpendicular to the focal line 422 is an arc, but this shape is not limited, and for example, it may also be a parabola. Further, the focal line 412 is a line obtained by connecting the foci of the convex mirror 410, and the focal line 422 is a line obtained by connecting the foci of the concave mirror 420. In addition, the shapes of the convex mirror 410 and the concave mirror 420 are not limited. For example, the shape of the convex mirror 410 may also be a rectangle that is longer in the direction perpendicular to the focal line 412, and the shape of the concave mirror 420 may also be a rectangle that is longer in the direction perpendicular to the focal line 422.

[0070] As Figure 4As shown, the focal line 412 is included in a plane that includes the optical axis LA1 of the laser and extends in the direction in which the electrodes 332a and 332b face each other, and is inclined so as to approach the electrode 332a side as it moves away from the cavity device CH3. Further, the focal line 422 is included in a plane that includes the optical axis LA1 of the laser and the focal line 412, and is inclined so as to approach the electrode 332b side as it moves away from the cavity device CH3. Further, the reflecting surface 431 of the plane mirror 430 is parallel to the optical axis LA1 of the laser and perpendicular to the surface of the output coupler mirror 370 on the side closer to the beam expander 400. This surface is the incident side surface 370s on which the laser from the cavity device CH3 is incident. Moreover, the focal line 412v of the virtual image 410v of the convex mirror 410 formed by the reflecting surface 431 is located on the same straight line as the focal line 422 of the concave mirror 420. That is, the positions of the convex mirror 410, the concave mirror 420, and the plane mirror 430 are adjusted in this way. Additionally, the focal line 412v and the focal line 422 may not be located on the same straight line. In Figure 4 , the virtual image 410v and the focal line 412v of this virtual image 410v are indicated by dashed lines.

[0071] The holding unit 470 includes a first holding unit 471 and a second holding unit 472. The first holding unit 471 is a component that holds the convex mirror 410, the concave mirror 420, and the plane mirror 430. The first holding unit 471 includes a planar placement surface 473, and the convex mirror 410, the concave mirror 420, and the plane mirror 430 are placed on this placement surface 473. The placement surface 473 is parallel to the optical axis LA1 of the laser and perpendicular to the direction in which the electrodes 332a and 332b face each other. In this example, the convex mirror 410 is placed on the placement surface 473 in a state where one of the two side surfaces extending along the length direction of the convex mirror 410 faces the placement surface 473. The concave mirror 420 is placed on the placement surface 473 in a state where one of the two side surfaces extending along the length direction of the concave mirror 420 faces the placement surface 473. The plane mirror 430 is placed on the placement surface 473 in a state where one of the two side surfaces extending along the length direction of the plane mirror 430 faces the placement surface 473. The convex mirror 410, the concave mirror 420, and the plane mirror 430 are fixed to the placement surface 473 using, for example, an adhesive (not shown) and are held by the first holding unit 471. As the adhesive, for example, an ultraviolet curable resin is cited.

[0072] The second holding portion 472 is a component that holds the output coupling mirror 370, and in this example, is a plate-shaped component that extends in a direction substantially perpendicular to the optical axis LA1 of the laser. An output coupling mirror holder 375 that holds the output coupling mirror 370 is fixed to the second holding portion 472, and the output coupling mirror 370 is held by the second holding portion 472. A through hole is provided in the second holding portion 472 for the laser light that passes through the output coupling mirror 370. In addition, the first holding portion 471 is fixed to the second holding portion 472. The second holding portion 472 is mounted on the cavity plate 512 located on the side of the window 331a.

[0073] A partial reflection film having a predetermined reflectivity is applied to the incident side surface 370s of the output coupling mirror 370. The output coupling mirror 370 reflects a portion of the laser light from the cavity device CH3 having its beam width expanded by the beam expander 400 toward the beam expander 400, and transmits the other portion of the laser light.

[0074] The output coupling mirror 370 may also be circular. The incident side surface 370 s and the surface opposite to the incident side surface 370 s are flat surfaces. The rear mirror 371 has a similar structure to the output coupling mirror 70 .

[0075] A resonator that resonates the laser light amplified by the electrodes 332a and 332b is formed by the rear mirror 371 and the output coupling mirror 370 disposed across the housing 330. The housing 330 and the beam expander 400 are arranged on the optical path of the resonator. The laser light emitted from the window 331a of the housing 330 is incident on the output coupling mirror 370 via the beam expander 400, and a part of it is reflected at the output coupling mirror 370. The laser light reflected at the output coupling mirror 370 returns to the internal space of the housing 330 via the beam expander 400 and the window 331a, and is emitted from the window 331b. The laser light emitted from the window 331b is reflected at the rear mirror 371, and returns to the internal space of the housing 330 via the window 331b. In this way, the laser light emitted from the housing 330 reciprocates between the rear mirror 371 and the output coupling mirror 370. The reciprocating laser light is amplified each time it passes through the laser gain space between the electrode 332a and the electrode 332b. That is, the resonator resonates light between both sides of the cavity device CH3, and the output coupling mirror 370 is arranged on one side of the cavity device CH3. A part of the amplified laser light passes through the output coupling mirror 370. The laser light passing through the output coupling mirror 370 travels toward the detection unit 153.

[0076] The detection section 153 includes a beam splitter 153 b and a photosensor 153 c as main structures.

[0077] The beam splitter 153b is arranged on the optical path of the laser passing through the output coupling mirror 370. The beam splitter 153b allows the laser passing through the output coupling mirror 370 to pass through with a high transmittance and go to the exit window 173, and reflects a part of the laser to the light-receiving surface of the light sensor 153c.

[0078] The light sensor 153c measures the pulse energy of the laser incident on the light-receiving surface of the light sensor 153c. The light sensor 153c is electrically connected to the processor 190 and outputs a signal representing the measured pulse energy to the processor 190. The processor 190 controls the voltages applied to the electrodes 32a and 32b of the amplifier 160 according to this signal.

[0079] An exit window 173 is provided on the side opposite to the output coupling mirror 370 with respect to the beam splitter 153b of the detection unit 153 as a reference. The exit window 173 is provided on the wall of the housing 110. The light passing through the beam splitter 153b is emitted from the exit window 173 to the exposure device 200 outside the housing 110. This laser is, for example, pulsed laser with a central wavelength of 193.4 nm.

[0080] The display unit 180 is a monitor that displays the state of the control performed by the processor 190 according to a signal from the processor 190. The display unit 180 may be arranged outside the housing 110.

[0081] The processor 190 of the present disclosure is a processing device including a storage device storing a control program and a CPU (Central Processing Unit) that executes the control program. The processor 190 is particularly configured or programmed to execute various processes included in the present disclosure. In addition, the processor 190 controls the entire gas laser device 100. In addition, the processor 190 is electrically connected to an exposure processor (not shown) of the exposure device 200 and exchanges various signals with the exposure processor.

[0082] The laser gas exhaust device 701 and the laser gas supply device 703 are electrically connected to the processor 190 through signal lines (not shown). The laser gas exhaust device 701 includes an exhaust pump (not shown) and discharges the laser gas from the internal space of the housings 30 and 330 through the pipe by suction of the exhaust pump according to a control signal from the processor 190. The laser gas supply device 703 supplies the laser gas from a laser gas supply source (not shown) arranged outside the housing 110 to the internal space of the housings 30 and 330 through the pipe according to a control signal from the processor 190.

[0083] 2.2 Operation

[0084] Next, the operation of the gas laser device 100 of the comparative example will be described.

[0085] In a state before the gas laser device 100 emits laser light, laser gas is supplied from the laser gas supply device 703 to the internal spaces of the housings 30 and 330.

[0086] When the gas laser device 100 emits laser light, the processor 190 receives a signal indicating the target energy Et and a light emission trigger signal from the exposure processor. The target energy Et is the target value of the energy of the laser light used in the exposure process. The processor 190 sets a prescribed charging voltage for the charger 41 so that the energy E becomes the target energy Et, and turns on the switch of the pulse power module 43 in synchronization with the light emission trigger signal. Thereby, the pulse power module 43 generates a pulsed high voltage using the electric energy held by the charger 41 and applies the high voltage between the electrode 32a and the electrode 32b. When the high voltage is applied, a discharge occurs between the electrode 32a and the electrode 32b, and the laser medium contained in the laser gas between the electrode 32a and the electrode 32b becomes an excited state, and light is emitted when the laser medium returns to the ground state. The emitted light resonates between the grating 63 and the output coupler 70 and is amplified each time it passes through the discharge space in the internal space of the housing 30, generating laser oscillation. The laser includes first linearly polarized light, and when passing through the windows 31a and 31b, the linearly polarized light having a polarization direction different from that of the first linearly polarized light in the laser light decreases. A part of the laser light passes through the output coupler 70, is reflected by the high reflectors 141b and 141c, passes through the rear mirror 371 and the window 331b, and travels into the housing 330.

[0087] The processor 190 turns on the switch of the pulse power module 343 so that a discharge occurs when the laser light from the laser oscillator 130 travels to the discharge space in the housing 330. That is, the processor 190 controls the pulse power module 343 so as to apply a high voltage to the electrodes 332a and 332b after a prescribed delay time has elapsed from the timing of turning on the switch of the pulse power module 43.

[0088] Thus, the laser incident on the amplifier 160 is amplified in the amplifier 160. In addition, the laser traveling into the internal space of the housing 330 travels toward the output coupling mirror 370 via the window 331a and the beam expander 400 as described above and is reflected by the output coupling mirror 370. The laser reflected by the output coupling mirror 370 travels into the internal space of the housing 330 via the beam expander 400 and the window 331a and exits from the window 331b. The light exiting from the window 331b is reflected by the rear mirror 371 and travels into the internal space of the housing 330 via the window 331b. In this way, the laser of a specified wavelength reciprocates between the rear mirror 371 and the output coupling mirror 370. The laser includes the first linearly polarized light, and the linearly polarized light having a polarization direction different from that of the first linearly polarized light in the laser decreases when the laser passes through the windows 331a and 331b. In addition, the laser is amplified each time it passes through the discharge space inside the housing 330, and a part of the laser becomes amplified laser light.

[0089] In the beam expander 400, the laser exiting from the cavity device CH3 is incident on the reflecting surface 411 of the convex mirror 410 such that the first linearly polarized light in the laser becomes S-polarized light. The reflecting surface 411 reflects the laser so as to expand the beam width of the laser. The laser reflected by the convex mirror 410 is incident on the reflecting surface 431 of the plane mirror 430 such that the first linearly polarized light in the laser becomes S-polarized light, and the reflecting surface 431 reflects the laser toward the concave mirror 420. The laser reflected by the plane mirror 430 is incident on the reflecting surface 421 of the concave mirror 420 such that the first linearly polarized light in the laser becomes S-polarized light. The reflecting surface 421 reflects the laser toward the output coupling mirror 370 so as to collimate the expanded beam width of the laser to be fixed. Generally, an optical element that reflects light has a tendency to be less likely to deteriorate over time compared to an optical element that transmits light. Therefore, compared with the case where the beam expander 400 is composed of a prism that transmits light, the deterioration of the beam expander 400 over time is suppressed. In addition, most of the polarization components included in the amplified laser become the first linearly polarized light. Such laser light is incident on the reflecting surface 411, the reflecting surface 421, and the reflecting surface 431 such that the first linearly polarized light in the laser becomes S-polarized light and is reflected. The reflectance of S-polarized light tends to be higher than the reflectance of P-polarized light. Therefore, a decrease in the amount of light on the reflecting surface 411, the reflecting surface 421, and the reflecting surface 431 is suppressed.

[0090] In addition, the amplified laser from the amplifier 160 passes through the output coupling mirror 370 and travels toward the beam splitter 153b.

[0091] A part of the amplified laser traveling toward the beam splitter 153b passes through the beam splitter 153b and the exit window 173 and travels toward the exposure device 200, and the other part is reflected by the beam splitter 153b and travels toward the optical sensor 153c.

[0092] The optical sensor 153c measures the energy E of the amplified laser received. The optical sensor 153c outputs a signal indicating the measured energy E to the processor 190. The processor 190 performs feedback control on the charging voltages of the chargers 41 and 341 such that the difference ΔE between the energy E and the target energy Et is within an allowable range.

[0093] 2.3 Method for manufacturing the beam expander

[0094] Next, a method for manufacturing the beam expander 400 in the comparative example will be described.

[0095] In this example, first, a holding portion 470 holding the output coupling mirror 370, a convex mirror 410, a concave mirror 420, and a plane mirror 430 are prepared. Next, the convex mirror 410, the concave mirror 420, and the plane mirror 430 are respectively arranged at the designed positions on the arrangement surface 473 of the first holding portion 471 and fixed using an adhesive. In this way, the beam expander 400 is manufactured.

[0096] 2.4 Problems

[0097] The dimensions of the convex mirror 410, the concave mirror 420, and the plane mirror 430 include manufacturing tolerances. In addition, the dimensions of the designed positions of these mirrors also include tolerances. Therefore, even if these mirrors are arranged at the designed positions, sometimes the performance of the laser deviates from the designed value, and there are cases where the positions of these mirrors need to be adjusted. In the adjustment of the arrangement of these mirrors, when the reflection surface 431 of the plane mirror 430 is not perpendicular to the incident side surface 370s of the output coupling mirror 370, even if the positions of the convex mirror 410 and the concave mirror 420 are adjusted, the performance of the laser sometimes still deviates from the designed value. Therefore, there is a requirement as follows: to make the reflection surface 431 perpendicular to the incident side surface 370s and to suppress the case where the performance of the laser deviates from the designed value.

[0098] Therefore, in the following embodiments, a method for manufacturing an optical module that can suppress the case where the performance of the laser deviates from the designed value is exemplified.

[0099] 3. Description of the beam expander and the method for manufacturing the beam expander according to Embodiment 1

[0100] Next, the beam expander 400 and the method for manufacturing the beam expander 400 according to Embodiment 1 will be described. In addition, the same reference numerals are assigned to the structures having the same structure as those described above, and redundant descriptions are omitted except in cases where special explanations are required. In addition, in some of the drawings, a part of the components is omitted or simplified for easy observation.

[0101] 3.1 Structure

[0102] Figure 6 In the same manner as Figure 4 FIG. shows a schematic structural example of the beam expander 400 of the present embodiment. As Figure 6 shown, the main difference between the beam expander 400 of the present embodiment and the beam expander 400 of the comparative example is that it further includes a convex mirror holder 440, a concave mirror holder 450, a convex mirror base 480, and a flat mirror base 490.

[0103] The convex mirror holder 440 is a plate-shaped member extending along one of the two sides extending in the length direction of the convex mirror 410. This side of the convex mirror 410 is fixed to the convex mirror holder 440 by an adhesive, for example.

[0104] The concave mirror holder 450 is a plate-shaped member extending along one of the two sides extending in the length direction of the concave mirror 420. This side of the concave mirror 420 is fixed to the concave mirror holder 450 by an adhesive, for example. The concave mirror holder 450 is fixed to the arrangement surface 473 of the first holding portion 471 by bolts, for example.

[0105] The convex mirror base 480 is a member to which the convex mirror holder 440 is fixed. The convex mirror base 480 of the present embodiment is a plate-shaped member. The convex mirror base 480 is mounted on the arrangement surface 473 by three screws 481 in a state where one main surface of the convex mirror base 480 faces the arrangement surface 473 of the first holding portion 471. The convex mirror base 480 is separated from the arrangement surface 473, and the inclination of the convex mirror base 480 with respect to the arrangement surface 473 can be changed by the three screws 481. In Figure 6 only one screw 481 is labeled. On the main surface 482 of the convex mirror base 480 on the side opposite to the arrangement surface 473 side, the convex mirror holder 440 is fixed by an adhesive 483. That is, the convex mirror 410 is fixed to the arrangement surface 473 via the convex mirror base 480 and the convex mirror holder 440. The adhesive 483 is separated into a plurality of adhesive portions, and the adhesive 483 is arranged between the convex mirror holder 440 and the main surface 482. Therefore, the convex mirror holder 440 and the main surface 482 are separated, and a space is formed in the region between the convex mirror holder 440 and the main surface 482 where the adhesive 483 is not arranged. In Figure 6 only one adhesive portion is labeled. In addition, the adhesive 483 may not be separated into a plurality of adhesive portions. Furthermore, the structure of the convex mirror base 480 is not limited as long as it can change the inclination with respect to the arrangement surface 473.

[0106] The flat mirror base 490 is a component to which the flat mirror 430 is fixed. The flat mirror base 490 of the present embodiment has the same structure as the convex mirror base 480, is mounted on the placement surface 473, and the inclination of the flat mirror base 490 relative to the placement surface 473 can be changed. On the main surface 492 of the flat mirror base 490 on the side opposite to the placement surface 473 side, the flat mirror 430 is fixed using an adhesive (not shown). That is, the flat mirror 430 is fixed to the placement surface 473 via the flat mirror base 490. Similar to the adhesive 483, the adhesive for fixing the flat mirror 430 can also be separated into a plurality of adhesive portions. In addition, the structure of the flat mirror base 490 is not limited as long as it can change the inclination relative to the placement surface 473.

[0107] 3.2 Method for manufacturing beam expander

[0108] Figure 7 FIG. is an example of a flowchart showing a method for manufacturing the beam expander 400 of the present embodiment. Hereinafter, the method for manufacturing the beam expander 400 may sometimes be simply referred to as the manufacturing method. As Figure 7 shown, the manufacturing method of the present embodiment includes a preparation step P1, an output coupling mirror placement step P2, a first autocollimator placement step P3, an optical element placement step P4, a second autocollimator placement step P5, a first mirror placement step P6, a wavefront sensor placement step P7, a pinhole plate placement step P8, a reference light source placement step P9, and a second mirror placement step P10.

[0109] (Preparation step P1)

[0110] This step is a step of preparing the components constituting the beam expander 400. In the present embodiment, the output coupling mirror 370 held by the holding portion 470, the convex mirror 410 fixed to the convex mirror holder 440, the concave mirror 420 fixed to the concave mirror holder 450, the flat mirror 430 fixed to the flat mirror base 490, and the convex mirror base 480 are prepared. Regarding the output coupling mirror 370, the orientation of the output coupling mirror 370 relative to the holding portion 470 is adjusted so that when the second holding portion 472 of the holding portion 470 is mounted on the cavity plate 512, the laser light from the cavity device CH3 is perpendicularly incident on the incident side surface 370s. In addition, it is adjusted so that the placement surface 473 of the first holding portion 471 in the holding portion 470 is perpendicular to the incident side surface 370s.

[0111] (Output coupling mirror placement step P2)

[0112] This step is a step of placing the output coupling mirror 370 at a specified position in the manufacturing jig 600 of the beam expander 400. Figure 8 FIG. shows the situation of this step. As Figure 8As shown, the manufacturing jig 600 of the present embodiment includes a plate 610, a jig base 620, and a plurality of stages. In Figure 8 , only the first stage 630 is described, and the description of other stages is omitted. The plate 610 is a plate-shaped member with one main surface 610s being a flat surface, and a plurality of stages can be arranged on this main surface 610s. Hereinafter, the direction perpendicular to the main surface 610s is set as the Y direction, the direction perpendicular to the Y direction is set as the X direction, and the direction perpendicular to the Y direction and the X direction is set as the Z direction for explanation.

[0113] The structure of the jig base 620 is the same as that of the cavity plate 512, and the holding portion 470 can be mounted and held. The jig base 620 is fixed to the main surface 610s. In the present embodiment, by mounting the holding portion 470 on the jig base 620, the output coupling mirror 370 is arranged at a specified position.

[0114] The first stage 630 is arranged on the main surface 610s on the side opposite to the jig base 620 compared with the holding portion 470, and includes a mounting surface 630s capable of mounting components such as a collimator described later. In the present embodiment, the first stage 630 includes a translation stage 631, a lifting stage 632, a rotating stage 633, and a gonio stage 634. The translation stage 631 can move in the X direction and the Z direction. The lifting stage 632 is arranged on the mounting surface 631s of the translation stage 631, and can move the mounting surface 632s on the side opposite to the mounting surface 631s in the Y direction. The rotating stage 633 is arranged on the mounting surface 632s of the lifting stage 632, and can rotate the mounting surface 633s on the side opposite to the mounting surface 632s around an axis parallel to the Y direction. The gonio stage 634 is arranged on the mounting surface 633s of the rotating stage 633, and the mounting surface on the side opposite to the mounting surface 633s is the mounting surface 630s of the first stage 630. The gonio stage 634 can tilt the mounting surface 630s around an axis perpendicular to the Y direction. Therefore, the first stage 630 can achieve the movement of the mounting surface 630s in the X direction, Y direction, and Z direction, the rotation of the mounting surface 630s around an axis parallel to the Y direction, and the tilting of the mounting surface 630s around an axis perpendicular to the Y direction.

[0115] (The first auto-collimator arrangement process P3)

[0116] This process is a process of arranging the first auto-collimator 710 in such a manner that the light emitted from the first auto-collimator 710 is perpendicularly incident on the incident side surface 370s of the output coupling mirror 370. Figure 9This is a diagram showing the situation of this process. In the present embodiment, the first autocollimator 710 is arranged on the mounting surface 630s of the first stage 630 in such a way that the light 711 from the first autocollimator 710 is incident on the incident-side surface 370s. Then, the first autocollimator 710 receives the light 711r reflected by the incident-side surface 370s, and measures the incident angle of the light 711 incident on the incident-side surface 370s through the first autocollimator 710. Based on the measurement result, the position of the first autocollimator 710, the inclination of the first autocollimator 710 with respect to the main surface 610s, and the orientation of the first autocollimator 710 in the direction parallel to the main surface 610s are adjusted by the first stage 630. Then, the light 711 emitted from the first autocollimator 710 is made to be incident perpendicularly on the incident-side surface 370s. In the present embodiment, the first autocollimator 710 is arranged in such a way that the incident angle of the light 711 with respect to the incident-side surface 370s is 0.02 mrad or less.

[0117] (Optical element arrangement process P4)

[0118] This process is a process of arranging the optical element 670. Figure 10 This is a diagram showing the situation of this process. Figure 11 It is a view from a direction perpendicular to the arrangement surface 473 Figure 10 showing the situation as shown. As Figure 10 , Figure 11 shown, the optical element 670 includes a first reflection surface 671 and a second reflection surface 672. The first reflection surface 671 and the second reflection surface 672 are planes that reflect light. The second reflection surface 672 forms an angle of 45° with the first reflection surface 671. The optical element 670 of the present embodiment is a triangular prism-shaped prism, and the first reflection surface 671 and the second reflection surface 672 are parts of the side surfaces of the prism. The two end surfaces in the extending direction of the optical element 670 are perpendicular to the first reflection surface 671 and the second reflection surface 672.

[0119] In this process, an optical element 670 is disposed between the incident-side surface 370s and the first autocollimator 710 such that the light 711 emitted from the first autocollimator 710 is incident perpendicularly on the first reflection surface 671. At this time, the first reflection surface 671 faces the first autocollimator 710, and the second reflection surface 672 faces the incident-side surface 370s. In the present embodiment, the optical element 670 is disposed on the disposition surface 473 of the first holding portion 471 via the optical element base 675. The optical element base 675 is disposed on the disposition surface 473 and can rotate about an axis perpendicular to the disposition surface 473. The optical element base 675 includes a placement surface 676 parallel to the disposition surface 473 on the side opposite to the disposition surface 473 side. The optical element 670 is disposed on the placement surface 676 such that the light 711 of the first autocollimator 710 is incident on the first reflection surface 671. Then, the first autocollimator 710 receives the light 711r reflected by the first reflection surface 671, and the first autocollimator 710 measures the incident angle of the light 711 incident on the first reflection surface 671. Based on the measurement result, the optical element base 675 is rotated so that the light 711 emitted from the first autocollimator 710 is incident perpendicularly on the first reflection surface 671. In the present embodiment, the optical element 670 is disposed such that the incident angle of the light 711 incident on the first reflection surface 671 is 0.02 mrad or less. In addition, the inclination of the optical element base 675 with respect to the disposition surface 473 can also be changed. Furthermore, the optical element base 675 may have any structure as long as it can dispose the optical element 670, and there is no limitation.

[0120] (Second Autocollimator Disposition Process P5)

[0121] This process is a process of disposing the second autocollimator 720 such that the light emitted from the second autocollimator 720 is reflected by the second reflection surface 672 and is incident perpendicularly on the incident-side surface 370s. Figure 12 This is a diagram showing the situation of this process. As Figure 12As shown, in the present embodiment, the second autocollimator 720 is arranged on the mounting surface 640s of the second stage 640 such that the light 721 from the second autocollimator 720 is reflected by the second reflecting surface 672 and incident on the surface 370s on the incident side. The second stage 640 has the same structure as the first stage 630 and is capable of moving in the X, Y, and Z directions of the mounting surface 640s, rotating the mounting surface 640s about an axis parallel to the Y direction, and tilting the mounting surface 640s about an axis perpendicular to the Y direction. Then, the second autocollimator 720 receives the light 721r that is reflected in sequence by the second reflecting surface 672, the surface 370s on the incident side, and the second reflecting surface 672, and measures the incident angle of the light 721 incident on the surface 370s on the incident side through the second autocollimator 720. According to the measurement result, the position, inclination, and orientation of the second autocollimator 720 are adjusted by the second stage 640. Then, the light 721 emitted from the second autocollimator 720 is reflected by the second reflecting surface 672 and perpendicularly incident on the surface 370s on the incident side. In the present embodiment, the second autocollimator 720 is arranged such that the incident angle of the light 721 incident on the surface 370s on the incident side is 0.02 mrad or less.

[0122] (First mirror arrangement step P6)

[0123] This step is a step of removing the optical element 670 and arranging the plane mirror 430 such that the light 721 from the second autocollimator 720 is perpendicularly incident on the reflecting surface 431 of the plane mirror 430. Figure 13 It is a diagram showing the situation of this step. As Figure 13 shown, in the present embodiment, first, the optical element 670 and the optical element base 675 are removed from the first holding portion 471. Then, the plane mirror base 490 fixed with the plane mirror 430 is mounted on the arrangement surface 473. That is, in the present embodiment, the plane mirror 430 is arranged on the arrangement surface 473 via the plane mirror base 490. The position where the plane mirror base 490 is mounted is a position where the light 721 is incident on the reflecting surface 431 of the plane mirror 430 and is on the side opposite to the second autocollimator 720 side compared with the optical axis of the light 711. Then, the second autocollimator 720 receives the light 721r reflected by the reflecting surface 431, and measures the incident angle of the light 721 incident on the reflecting surface 431 through the second autocollimator 720. Based on the measurement result, the inclination of the plane mirror base 490 with respect to the arrangement surface 473 is adjusted. Then, the light 721 from the second autocollimator 720 is perpendicularly incident on the reflecting surface 431 of the plane mirror 430. In the present embodiment, the plane mirror 430 is arranged such that the incident angle of the light 721 incident on the reflecting surface 431 is 1 mrad or less.

[0124] (Wavefront sensor configuration process P7)

[0125] This process is a process of configuring the wavefront sensor 730 in such a way that the light 711 of the first autocollimator 710 after passing through the output coupling mirror 370 is incident perpendicularly on the light receiving surface 731. Figure 14 This is a diagram showing the situation of this process. The wavefront sensor 730 can measure the incident angle of the incident light and the wavefront aberration of the incident light. In the present embodiment, the wavefront sensor 730 is arranged on the mounting surface 650s of the third stage 650 in such a way that the light 711 from the first autocollimator 710 passes through the output coupling mirror 370 and is incident on the light receiving surface 731 of the wavefront sensor 730. The third stage 650 has the same structure as the first stage 630 and can move in the X, Y, and Z directions of the mounting surface 650s, rotate the mounting surface 650s about an axis parallel to the Y direction, and tilt the mounting surface 650s about an axis perpendicular to the Y direction. Then, the incident angle of the light 711 incident on the light receiving surface 731 is measured by the wavefront sensor 730. Based on the measurement result, the position, tilt, and orientation of the wavefront sensor 730 are adjusted by the third stage 650. Then, the light 711 after passing through the output coupling mirror 370 is incident perpendicularly on the light receiving surface 731. In the present embodiment, the wavefront sensor 730 is arranged in such a way that the incident angle of the light 711 incident on the light receiving surface 731 is 0.05 mrad or less.

[0126] (Pinhole plate configuration process P8)

[0127] This process is a process of arranging the pinhole plate 735 provided with the through hole 736 in such a way that the light 711 passes through the through hole 736. Figure 15 This is a diagram showing the situation of this process. The pinhole plate 735 is a light-shielding plate-like member provided with a through hole 736 in the thickness direction. In the present embodiment, the pinhole plate 735 is arranged on the arrangement surface 473 in such a way that the optical axis of the light 711 passes through the through hole 736. The size of the through hole 736 is larger than the beam diameter of the light 711, and the light 711 can pass through the through hole 736 without being blocked. The outer shape of the through hole 736 may be a rectangular shape that is longer in the Y direction.

[0128] (Reference light source configuration process P9)

[0129] This process is a process of arranging the reference light source 740 instead of the first autocollimator 710 in such a way that the emitted light passes through the output coupling mirror 370 and is incident perpendicularly on the light receiving surface 731 of the wavefront sensor 730. Figure 16This is a diagram showing the situation of this process. The beam diameter of the light 741 emitted from the reference light source 740 is larger than the beam diameter of the light 711 of the first autocollimator 710. For example, the beam diameter of the light 741 is more than 10 times the beam diameter of the light 711, and is 10 mm or more. In addition, the beam diameter of the light 741 is larger than the outer shape of the through hole 736 of the pinhole plate 735. In the present embodiment, instead of the first autocollimator 710, the reference light source 740 is arranged on the placement surface 630s of the first stage 630. Then, the light 741 of the reference light source 740 passes through the through hole 736, passes through the output coupling mirror 370, and is incident on the light receiving surface 731 of the wavefront sensor 730. In addition, the optical axis of the light 741 passes through the through hole 736, and the entire through hole 736 is located within the area of the light 741 irradiated on the pinhole plate 735. Therefore, the outer shape of the light 741 after passing through the through hole 736 becomes the same shape as the outer shape of the through hole 736.

[0130] Next, the incident angle of the light 741 incident on the light receiving surface 731 is measured by the wavefront sensor 730. Based on the measurement result, the position, inclination, and orientation of the reference light source 740 are adjusted by the first stage 630. Then, the light 741 is made to be incident perpendicularly on the light receiving surface 731. In the present embodiment, the reference light source 740 is arranged so that the incident angle of the light 741 incident on the light receiving surface 731 is 0.02 mrad or less.

[0131] Alternatively, the pinhole plate 735 may be arranged after the first autocollimator 710 is removed. For example, after the reference light source 740 is arranged, the pinhole plate 735 may be arranged so that the optical axis of the light 741 passes through the through hole 736.

[0132] (Second mirror arrangement process P10)

[0133] This process is a process of arranging the convex mirror 410 and the concave mirror 420. Specifically, the convex mirror 410 is arranged to reflect the light 741 so that the beam width of the light 741 of the reference light source 740 is expanded and the light 741 is reflected toward the flat mirror 430. In addition, the concave mirror 420 is arranged to collimate so that the expanded beam width of the light 741 reflected by the flat mirror 430 becomes fixed, and the light 741 is reflected so that the light 741 passes through the output coupling mirror 370 and is perpendicularly incident on the light receiving surface 731 of the wavefront sensor 730.

[0134] Figure 17This is a diagram showing the situation where the concave mirror 420 is configured. In this embodiment, first, the concave mirror holder 450 fixed with the concave mirror 420 is arranged on the arrangement surface 473 of the first holder 471. That is, the concave mirror 420 is arranged on the arrangement surface 473 via the concave mirror holder 450. The position where the concave mirror 420 is arranged is closer to the output coupling mirror 370 side than the pinhole plate 735. The reflecting surface 421 of the concave mirror 420 intersects with the optical axis of the light 741 of the reference light source 740. In addition, the concave mirror 420 is located at a position closer to the output coupling mirror 370 side than the plane mirror 430 and is inclined from the output coupling mirror 370 side toward the reference light source 740 side toward the plane mirror 430 side. In addition, the focal line 422 of the concave mirror 420 is parallel to the arrangement surface 473. That is, the position where the concave mirror 420 is arranged is a position that satisfies the above content. This position can also be determined in advance on the arrangement surface 473 and positioned by a positioning pin, an abutting groove, etc. Therefore, a hole for fitting the positioning pin can also be provided in the concave mirror holder 450. The concave mirror holder 450 arranged in this way is fixed to the arrangement surface 473 by bolts.

[0135] Next, the convex mirror base 480 is installed on the arrangement surface 473. The position where the convex mirror base 480 is installed is a position between the concave mirror 420 and the pinhole plate 735 and overlapping with the optical axis of the light 741 in the direction perpendicular to the arrangement surface 473. This position can also be determined in advance and defined by the same positioning structure as the concave mirror holder 450.

[0136] Next, the convex mirror 410 is arranged. Figure 18 This is a diagram showing the situation where the convex mirror 410 is arranged. Figure 19 It is along Figure 18 the arrow A in Figure 18 to observe a part of the situation shown in Figure 18 . Figure 19 As shown in

[0137] Next, the position, tilt, and orientation of the convex mirror 410 are adjusted by the fourth 660. Then, the light 741 reflected by the convex mirror 410 is reflected by the plane mirror 430 and the concave mirror 420 in sequence and is incident on the incident-side surface 370s. At this time, the main surface 482 of the convex mirror holder 440 and the convex mirror base 480 is separated by a distance greater than a specified distance. The specified distance is, for example, 0.1 mm. The convex mirror 410 expands the beam width of the light 741 and reflects the light 741 toward the plane mirror 430. In addition, the concave mirror 420 reflects the light 741 in a collimated manner so that the expanded beam width of the light 741 reflected by the plane mirror 430 becomes fixed. The light 741 reflected by the concave mirror 420 passes through the output coupling mirror 370 and is incident on the wavefront sensor 730.

[0138] Next, the incident angle of the light 741 incident on the light-receiving surface 731 and the RMS (Root Mean Square) value of the wavefront aberration of the light 741 are measured by the wavefront sensor 730. Based on the measurement result, the position, tilt, and orientation of the convex mirror 410 are adjusted by the fourth 660 so that the light 741 passing through the output coupling mirror 370 is incident on the wavefront sensor 730 perpendicularly. In this way, the focal line 412v of the virtual image 410v of the convex mirror 410 and the focal line 422 of the concave mirror 420 are located on the same straight line. In the present embodiment, the reference light source 740 is arranged so that the incident angle of the light 741 incident on the light-receiving surface 731 is 0.2 mrad or less and the RMS value of the wavefront aberration of the light 741 is 13.51 nm (0.07 × 193 nm) or less. Additionally, when not considering the wavefront aberration, it is also possible not to measure the RMS value of the wavefront aberration of the light 741 incident on the light-receiving surface 731 by the wavefront sensor 730.

[0139] Next, using the fourth stage 660, the convex mirror holder 440 is moved a predetermined distance in the Y direction in such a manner that the convex mirror holder 440 approaches the convex mirror base 480. The predetermined distance is shorter than the distance between the convex mirror holder 440 and the convex mirror base 480 before the movement, for example, 0.1 mm. Next, the inclination of the convex mirror base 480 is adjusted in such a manner that the main surface 482 of the convex mirror base 480 is in surface contact with the convex mirror holder 440. Next, using the fourth stage 660, the convex mirror holder 440 is moved a predetermined distance in the Y direction in such a manner that the convex mirror holder 440 moves away from the convex mirror base 480. The predetermined distance is the same as the distance moved when the convex mirror holder 440 approaches the convex mirror base 480. Then, the incident angle of the light 741 incident on the light receiving surface 731 and the RMS value of the wavefront aberration of the light 741 are measured again, and based on the measurement results, the position, inclination, and orientation of the convex mirror 410 are adjusted using the fourth stage 660 in such a manner that the light 741 is incident perpendicularly on the wavefront sensor 730. Therefore, in a state where the light 741 is incident perpendicularly on the wavefront sensor 730, a gap with a predetermined distance is formed between the convex mirror holder 440 and the main surface 482 of the convex mirror base 480. In addition, the adjustment of the position, inclination, and orientation of the convex mirror 410 after the convex mirror holder 440 is moved in the Y direction in such a manner that the convex mirror holder 440 moves away from the convex mirror base 480 may be omitted. Furthermore, the movement of the convex mirror holder 440 in the Y direction and the adjustment of the convex mirror 410 after the convex mirror 410 is initially adjusted may also be omitted.

[0140] Next, in a state where the convex mirror holder 440 is separated from the convex mirror base 480, the convex mirror holder 440 is fixed to the convex mirror base 480 using an adhesive. The fixing with the adhesive is as Figure 6 described in the explanation. After the adhesive is cured, the support bar 750 is removed from the convex mirror holder 440, and the pinhole plate 735 is removed from the placement surface 473.

[0141] In this way, the beam expander 400 is manufactured. The holding portion 470 of the beam expander 400 is attached to the cavity plate 512. As described above, the orientation of the output coupling mirror 370 with respect to the holding portion 470 is adjusted in advance. Therefore, by attaching the holding portion 470 to the cavity plate 512, the beam expander 400 is configured such that the laser light emitted from the cavity device CH3 is incident perpendicularly on the incident side surface 370s. Then, the gas laser device 100 is manufactured.

[0142] 3.3 Function / Effect

[0143] The manufacturing method of this embodiment has a first auto - collimator configuration step P3, an optical element configuration step P4, a second auto - collimator configuration step P5, and a first mirror configuration step P6. In the first auto - collimator configuration step P3, the first auto - collimator 710 is arranged in such a way that it receives the light 711 reflected by the surface 370s on the incident side of the output coupling mirror 370 among the emitted light 711 and makes the light 711 perpendicularly incident on the incident - side surface 370s. That is, the optical axis of the light 711 can be made perpendicular to the incident - side surface 370s. In the optical element configuration step P4, the optical element 670 is arranged in such a way that the first auto - collimator 710 receives the light 711 reflected by the first reflecting surface 671 of the optical element 670 among the light 711 emitted from the first auto - collimator 710 and makes the light 711 perpendicularly incident on the first reflecting surface 671. In the second auto - collimator configuration step P5, the second auto - collimator 720 is arranged in such a way that it receives the light 721 reflected successively by the second reflecting surface 672 of the optical element 670, the incident - side surface 370s, and the second reflecting surface 672 among the emitted light 721 and makes the light 721 perpendicularly incident on the incident - side surface 370s. The angle formed by the first reflecting surface 671 and the second reflecting surface 672 is 45°. Therefore, through the second auto - collimator configuration step P5, the optical axis of the light 721 can be made perpendicular to the optical axis of the light 711. In the first mirror configuration step P6, the plane mirror 430 is arranged in such a way that the second auto - collimator 720 receives the light 721 reflected by the reflecting surface 431 of the plane mirror 430 among the light 721 emitted from the second auto - collimator 720 and makes the light 721 perpendicularly incident on the reflecting surface 431. Since the optical axis of the light 711 is perpendicular to the incident - side surface 370s and the optical axis of the light 721 is perpendicular to the optical axis of the light 711, the reflecting surface 431 of the plane mirror 430 can be made perpendicular to the incident - side surface 370s. Therefore, compared with the case where the plane mirror 430 is arranged at the design position with mechanical precision, the amount by which the angle formed by the reflecting surface 431 and the incident - side surface 370s deviates from the perpendicular can be reduced. Therefore, according to the manufacturing method of this embodiment, by adjusting the arrangement of the convex mirror 410 and the concave mirror 420, the performance of the laser can be made the design value, and the situation where the performance of the laser deviates from the design value can be suppressed.

[0144] In the optical element configuration step P4 in the manufacturing method of this embodiment, the optical element 670 is arranged on the configuration surface 473 via an optical element base 675 that can rotate around an axis perpendicular to the configuration surface 473. Therefore, compared with the case where the optical element 670 is directly arranged on the configuration surface 473 without passing through the optical element base 675, fine adjustment is easier, and it is easier to make the light 711 perpendicularly incident on the first reflecting surface 671. In addition, the optical element base 675 can also be directly arranged on the configuration surface 473.

[0145] In the second mirror arrangement step P10 of the manufacturing method of the present embodiment, before arranging the convex mirror 410, the concave mirror 420 is fixed to the holding portion 470. The convex mirror 410 is located on the side opposite to the output coupling mirror 370 side compared to the concave mirror 420. Therefore, in the arrangement of the convex mirror 410, the output coupling mirror 370 is less likely to become an obstacle compared to the arrangement of the concave mirror 420. Therefore, compared with the case where the convex mirror 410 is fixed to the holding portion 470 before arranging the concave mirror 420, the second mirror arrangement step P10 can be easily performed. Alternatively, the convex mirror 410 may be fixed to the holding portion 470 before arranging the concave mirror 420.

[0146] In the second mirror arrangement step P10 of the manufacturing method of the present embodiment, the convex mirror 410 is arranged on the holding portion 470 via the convex mirror base 480 capable of changing the inclination with respect to the arrangement surface 473. Therefore, compared with the case where the convex mirror 410 is directly arranged on the holding portion 470 without passing through the convex mirror base 480, the convex mirror 410 whose orientation and the like have been adjusted can be easily arranged on the holding portion 470. Similarly to the convex mirror base 480, the concave mirror 420 may be arranged on the holding portion 470 via the concave mirror base capable of changing the inclination with respect to the arrangement surface 473.

[0147] In the second mirror arrangement step P10 of the manufacturing method of the present embodiment, in a state where the convex mirror holder 440 to which the convex mirror 410 is fixed is separated from the convex mirror base 480, the convex mirror holder 440 is fixed to the convex mirror base 480 using an adhesive. For example, when the convex mirror holder 440 is fixed to the convex mirror base 480 using bolts, the position of the convex mirror 410 may shift due to the tightening force of the bolts, causing the convex mirror holder 440 to tilt with respect to the convex mirror base 480. According to the manufacturing method of the present embodiment, compared with this case, the position shift of the convex mirror 410 can be suppressed. Alternatively, the convex mirror holder 440 may be fixed by bolts.

[0148] In the reference light source arrangement step P9 of the manufacturing method of the present embodiment, the reference light source 740 is arranged such that the optical axis of the light 741 passes through the through hole 736 of the pinhole plate 735 having a through hole 736 smaller than the beam diameter of the light 741 of the reference light source 740. Further, in the second mirror arrangement step P10, the convex mirror 410 and the concave mirror 420 are arranged on the side closer to the output coupling mirror 370 than the pinhole plate 735. Therefore, the outer shape of the light 741 can be made into a shape corresponding to the outer shape of the through hole 736. Therefore, for example, the arrangement of the convex mirror 410 and the concave mirror 420 can be adjusted so that the characteristics of the wavefront aberration of the laser having a desired outer shape satisfy the desired requirements.

[0149] As described above, the present invention has been described by taking the embodiments as examples. However, the above embodiments can be appropriately modified. For example, the optical element 670 including the first reflecting surface 671 and the second reflecting surface 672 is a prism, but it may also be a columnar reflecting member that does not transmit light.

[0150] In addition, in the second mirror arranging step P10, the concave mirror 420 is arranged on the arranging surface 473 of the holding portion 470 via the concave mirror holder 450. However, the concave mirror 420 may also be directly arranged on the arranging surface 473, and the concave mirror 420 may also be arranged on a surface different from the arranging surface 473 on which the plane mirror 430 is arranged.

[0151] In addition, in the second mirror arranging step P10, the convex mirror 410 is arranged on the convex mirror base 480 via the convex mirror holder 440. However, the convex mirror 410 may also be directly arranged on the convex mirror base 480. In addition, the convex mirror 410 may also be directly arranged on the holding portion 470. For example, it may be directly arranged on the arranging surface 473.

[0152] In addition, the manufacturing method of the above embodiment is a manufacturing method of the beam expander 400 of the optical module. However, the optical module is not limited to the beam expander 400.

[0153] In addition, the manufacturing method of the above embodiment includes the pinhole plate arranging step P8, but the pinhole plate arranging step P8 may not be included.

[0154] The above description is not restrictive but merely illustrative. Therefore, those skilled in the art will understand that modifications can be made to the embodiments of the present disclosure without departing from the claims. In addition, those skilled in the art will also understand that the embodiments of the present disclosure can be used in combination. As long as it is not explicitly stated, the terms used throughout this specification and the claims should be interpreted as "non-restrictive" terms. For example, terms such as "comprising", "having", "including", and "possessing" should be interpreted as "not excluding the existence of structural elements other than the recited structural elements". In addition, the modifier "a" should be interpreted as meaning "at least one" or "one or more". In addition, a term such as "at least one of A, B, and C" should be interpreted as "A", "B", "C", "A + B", "A + C", "B + C", or "A + B + C", and it should be interpreted as also including combinations of them and parts other than "A", "B", and "C".

Claims

1. A method for manufacturing an optical module, the optical module comprising: an output coupling mirror that transmits a portion of laser light and reflects another portion of the laser light; and a plane mirror that includes a plane reflection surface that is perpendicular to a surface of the output coupling mirror on the incident side of the laser light, wherein: The manufacturing method of the optical module comprises the following steps: a first auto-collimator arranging step of arranging the first auto-collimator so that the first auto-collimator receives light reflected from the incident side surface among the light emitted from the first auto-collimator and makes the light incident perpendicularly to the incident side surface; An optical element arrangement step of arranging an optical element between the incident side surface and the first automatic collimator in such a manner that the first automatic collimator receives light reflected by a first reflection surface among the light emitted from the first automatic collimator and the light is vertically incident on the first reflection surface, wherein the first reflection surface is a reflection surface included in the optical element and is opposite to the first automatic collimator, and the optical element includes a second reflection surface that forms an angle of 45° with the first reflection surface and is opposite to the incident side surface; a second auto-collimator disposing step, disposing the second auto-collimator in such a manner that the second auto-collimator receives light reflected sequentially from the second reflection surface, the incident surface, and the second reflection surface among the light emitted from the second auto-collimator, and the light is vertically incident on the incident surface; as well as The first reflecting mirror arranging step removes the optical element and arranges the plane mirror so that the second autocollimator receives light reflected on the reflecting surface of the plane mirror among the light emitted from the second autocollimator and the light is vertically incident on the reflecting surface.

2. The method for manufacturing an optical module according to claim 1, wherein: The optical element is a prism, and the first reflecting surface and the second reflecting surface are respectively part of side surfaces of the prism.

3. The method for manufacturing an optical module according to claim 1, wherein: The optical module further comprises a holding portion for holding the output coupling mirror. In the first reflecting mirror placement step, the plane mirror is placed on the holding portion.

4. The method for manufacturing an optical module according to claim 3, wherein: The holding portion includes a configuration surface on which the plane mirror is configured. In the optical element placement step, the optical element is placed on the placement surface via an optical element base that is rotatable around an axis perpendicular to the placement surface.

5. The method for manufacturing an optical module according to claim 3, wherein: The holding portion includes a configuration surface on which the plane mirror is configured. In the first reflecting mirror placement step, the plane mirror is placed on the placement surface via a plane mirror base capable of changing an inclination with respect to the placement surface.

6. The method for manufacturing an optical module according to claim 1, wherein: The optical module also includes a convex mirror and a concave mirror. The manufacturing method of the optical module further comprises the following steps: a wavefront sensor configuration step of configuring the wavefront sensor after the first reflector configuration step so that the light of the first autocollimator after passing through the output coupling mirror is vertically incident on the light receiving surface of the wavefront sensor; A reference light source configuration step of configuring a reference light source, replacing the first autocollimator, and arranging a light source whose beam diameter is larger than that of the first autocollimator, so that the light of the reference light source is transmitted through the output coupling mirror and vertically incident on the light receiving surface of the wavefront sensor; as well as a second reflecting mirror configuration step of configuring the convex mirror and the concave mirror, In the second reflector configuration step, configuring the convex mirror to reflect light from the reference light source so that the beam width of the light is expanded and reflected toward the plane mirror, The concave mirror is configured to collimate the light reflected from the plane mirror so that the expanded beam width is fixed, and to reflect the light so that the light passes through the output coupling mirror and is vertically incident on the light receiving surface of the wavefront sensor.

7. The method for manufacturing an optical module according to claim 6, wherein: The optical module further comprises a holding portion for holding the output coupling mirror. In the second reflecting mirror arrangement step, the convex mirror and the concave mirror are arranged on the holding portion.

8. The method for manufacturing an optical module according to claim 7, wherein: In the second reflecting mirror arrangement step, the concave mirror is fixed to the holding portion before the convex mirror is arranged.

9. The method for manufacturing an optical module according to claim 7, wherein: The holding portion includes a configuration surface on which the plane mirror is configured. In the second reflecting mirror arrangement step, the convex mirror is arranged on the holding portion via a convex mirror base capable of changing an inclination relative to the arrangement surface.

10. The method for manufacturing an optical module according to claim 9, wherein: In the second reflecting mirror arrangement step, the convex mirror is arranged on the convex mirror base via a convex mirror holder.

11. The method for manufacturing an optical module according to claim 10, wherein: In the second reflecting mirror arrangement step, the convex mirror holder is fixed to the convex mirror base using an adhesive in a state where the convex mirror holder is spaced apart from the convex mirror base.

12. The method for manufacturing an optical module according to claim 6, wherein: In the reference light source arrangement step, the reference light source is arranged so that the optical axis of the emitted light passes through the through hole of a pinhole plate provided with a through hole smaller than the beam diameter of the light of the reference light source. In the second reflecting mirror arrangement step, the convex mirror and the concave mirror are arranged at positions closer to the output coupling mirror than the pinhole plate.

13. A method for manufacturing a gas laser device, the gas laser device comprising: a cavity device that amplifies laser light output from a laser oscillator; and an optical module, comprising an output coupling mirror and a plane mirror, wherein the output coupling mirror transmits a portion of the laser light emitted from the cavity device and reflects another portion of the laser light emitted from the cavity device to return to the cavity device, and the plane mirror comprises a plane reflection surface perpendicular to a surface of the output coupling mirror on the incident side of the laser light, wherein The optical module manufactured by the following optical module manufacturing method is configured so that the laser light emitted from the cavity device is vertically incident on the incident side surface of the output coupling mirror, The manufacturing method of the optical module comprises the following steps: a first auto-collimator arranging step of arranging the first auto-collimator so that the first auto-collimator receives light reflected from the incident side surface among the light emitted from the first auto-collimator and makes the light incident perpendicularly to the incident side surface; An optical element arrangement step of arranging an optical element between the incident side surface and the first automatic collimator in such a manner that the first automatic collimator receives light reflected by a first reflection surface among the light emitted from the first automatic collimator and the light is vertically incident on the first reflection surface, wherein the first reflection surface is a reflection surface included in the optical element and is opposite to the first automatic collimator, and the optical element includes a second reflection surface that forms an angle of 45° with the first reflection surface and is opposite to the incident side surface; a second auto-collimator disposing step, disposing the second auto-collimator in such a manner that the second auto-collimator receives light reflected sequentially from the second reflection surface, the incident surface, and the second reflection surface among the light emitted from the second auto-collimator, and the light is vertically incident on the incident surface; as well as The first reflecting mirror arranging step removes the optical element and arranges the plane mirror so that the second autocollimator receives light reflected on the reflecting surface of the plane mirror among the light emitted from the second autocollimator and the light is vertically incident on the reflecting surface.

14. A manufacturing jig for an optical module, the optical module comprising: an output coupling mirror that transmits a portion of laser light and reflects another portion of the laser light; and a plane mirror that comprises a plane reflection surface that is perpendicular to a surface of the output coupling mirror on the incident side of the laser light, wherein: The manufacturing method of the optical module includes: a first autocollimator arranged so that light emitted from the first autocollimator is vertically incident on the incident side surface of the output coupling mirror; an optical element including a first reflecting surface opposed to the first autocollimator and a second reflecting surface that forms an angle of 45° with the first reflecting surface and is opposed to the incident surface, the optical element being arranged between the incident surface and the first autocollimator so that light emitted from the first autocollimator is perpendicularly incident on the first reflecting surface; and The second autocollimator is arranged so that the light emitted from the second autocollimator is reflected by the second reflection surface and vertically incident on the incident side surface.

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