Optical kit and optical device

Abstract

An optical kit for constituting an optical system of an external resonator of a laser source including output laser light, comprising: a base including a main surface; a light source holding portion provided on the main surface for holding the laser source; and a holding portion provided on the main surface for holding the optical system, the holding portion having a reflector holding portion for holding a corner reflector, a first opening member holding portion for holding a first opening member, and a second opening member holding portion for holding a second opening member, the first opening member holding portion being located at a position closer to the reflector holding portion side than an exit surface of the laser light of the laser source held by the light source holding portion.

Description

Technical Field

[0001] This invention relates to optical kits and optical devices. Background Technology

[0002] Non-Patent Document 1 describes an external cavity quantum cascade laser system. This laser system includes a quantum cascade laser, a collimating lens for collimating the laser beam from the quantum cascade, a diffraction grating for reflecting the 0th-order diffracted light from the collimating lens in a predetermined direction, and a mirror for further reflecting the 0th-order diffracted light from the diffraction grating. The diffraction grating and the mirror are mounted on a common rotatable platform, such that the extensions of the reflecting surfaces of the diffraction grating and the mirror intersect precisely on the platform's axis of rotation.

[0003] Existing technical documents

[0004] Non-patent literature

[0005] Non-Patent Literature 1: R. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing”, Applied Physics B, September 2008, Volume 92, Issue 3, pp. 305-311 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] By employing the structure of the laser system described above, the position and direction of the output laser beam can be fixed during the wavelength tuning process. In the application of such a laser system, if the position and direction of the output light deviate when the user exchanges the laser source for changes in wavelength band, etc., corresponding adjustments to the subsequent optical system are required. Therefore, the laser system itself may also require restoring the position and direction of the emitted light after exchanging the laser source. However, it is not easy to adjust the optical axis of the emitted light simultaneously with the fine adjustments needed to establish the external resonator. Furthermore, when the diffraction grating needs to be exchanged simultaneously with the exchanged laser source, the precise alignment required to fix the position and direction of the output light during the wavelength tuning process remains difficult to achieve. Moreover, this adjustment is particularly difficult when dealing with invisible light such as infrared light, as in Non-Patent Document 1.

[0008] The purpose of this invention is to provide an optical kit and optical device that allows for easy adjustment of the position and direction of the output light.

[0009] Methods for solving problems

[0010] The optical kit of the present invention is an optical kit for constructing an optical system comprising an external resonator of a laser source including an output laser beam. It includes: a base comprising a main surface; a light source holding portion disposed on the main surface for holding the laser source; and a holding portion disposed on the main surface for holding the optical system. The optical system includes: a corner reflector composed of a reflective diffraction grating and a mirror. The reflective diffraction grating diffracts laser light emitted from the laser source and incident from a first direction, reflecting the 0th order diffracted light in a second direction intersecting the first direction. The mirror reflects the diffracted light from the reflective diffraction grating in a third direction different from the first and second directions. It also includes optical openings that sequentially allow diffracted light from the corner reflector to pass through. The first and second opening members arranged in the third direction have a holding portion including: a reflector holding portion for holding the corner reflector; a first opening member holding portion for holding the first opening member; and a second opening member holding portion for holding the second opening member. The reflector holding portion includes a first mechanism capable of adjusting the optical axis of the diffracted light in each of the reflective diffraction grating and the mirror. The first opening member holding portion is located in the third direction closer to the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion. The second opening member holding portion is located in the third direction closer to the opposite side of the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion.

[0011] By using this optical kit, the position and direction of the output light can be adjusted as follows: First, the corner reflector is held in the reflector holding part. Then, the intensity of the diffracted light passing through the optical opening of the first opening member via the corner reflector is monitored, and the optical axis of the diffracted light from the reflective diffraction grating is adjusted using the second mechanism in such a way that the maximum intensity of that intensity is obtained. Once the maximum intensity of the diffracted light passing through the optical opening of the first opening member is obtained, the optical opening of the first opening member is sufficiently enlarged, or the first opening member is temporarily removed, and the intensity of the diffracted light passing through the optical opening of the second opening member via the corner reflector is monitored, and the optical axis of the diffracted light from the mirror is adjusted using the first mechanism in such a way that the maximum intensity of that intensity is obtained. The center of the optical opening of the first opening member and the center of the optical opening of the second opening member can be aligned in a straight line within the range of machining accuracy of the base and the holding part. Therefore, by alternately repeating the optical axis adjustment of the diffracted light while monitoring the intensity of the diffracted light passing through the optical opening of the first opening member and the optical axis adjustment of the diffracted light while monitoring the intensity of the diffracted light passing through the optical opening of the second opening member, the optical axis of the diffracted light passing through the optical opening of the first opening member and the second opening member can be aligned with a straight line.

[0012] As a result of these adjustments, the optical axis of the diffracted light emitted from the laser source and passing through the optical openings of the first and second opening members via the corner reflector is aligned with this straight line. This achieves a fixed position and direction of the output light. Thus, with this optical assembly, the position and direction of the output light can be easily adjusted. Specifically, in this optical assembly, the first opening member holding portion is located closer to the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion, and the second opening member holding portion is located closer to the opposite side of the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion. That is, in this optical assembly, the distance between the first and second opening members can be ensured. This suppresses the tilting of the optical axis (this straight line) of the diffracted light passing through both the optical openings of the first and second opening members, allowing for more precise adjustment of the position and direction of the output light.

[0013] In the optical kit of the present invention, the optical system may also have the following structure: the optical system includes: a lens disposed between a laser source and a corner reflector, into which laser light is input in a first direction; and a third opening member configured to form an optical opening through which laser light passes after passing through the lens without a corner reflector, wherein the laser light passes through the lens when the reflective diffraction grating is incident on the laser light, the holding part has: a lens holding part for holding the lens; and a third opening member holding part for holding the third opening member, and the reflector holding part includes a second mechanism for holding the entire corner reflector rotatably along the main surface.

[0014] In this configuration, the position and direction of the output light can be adjusted as follows: First, all optical components in the optical system, except for the corner reflector, are held in each holding section of the holding section. Furthermore, the laser source is positioned such that the laser light output from the laser source passes through the lens held in the lens holding section and through the optical opening of the third opening member held in the third opening member holding section. Then, the position of the laser source relative to the lens is adjusted by monitoring the light intensity of the laser light passing through the optical opening of the third opening member and simultaneously obtaining the maximum value of that light intensity. This achieves alignment between the light emission point of the laser source and the center of the lens. The center of the lens and the center of the optical opening of the third opening member can be aligned with another straight line within the range of machining accuracy of the base and holding section. Therefore, through the above-described process, the optical axis of the laser light output from the laser source through the lens is aligned with this other straight line.

[0015] Then, adjustments can be made using the second and third opening members as described above. That is, the corner reflector is held in the reflector holding part. Then, the optical axis of the diffracted light from the reflective diffraction grating is adjusted using the second mechanism in a manner that monitors the light intensity of the diffracted light passing through the optical opening of the first opening member via the corner reflector and simultaneously obtains the maximum value of that light intensity. Once the maximum value of the light intensity of the diffracted light passing through the optical opening of the first opening member is obtained, the optical opening of the first opening member is sufficiently enlarged, or the first opening member is temporarily removed, and the optical axis of the diffracted light from the mirror is adjusted using the first mechanism in a manner that monitors the light intensity of the diffracted light passing through the optical opening of the second opening member via the corner reflector and simultaneously obtains the maximum value of that light intensity. The center of the optical opening of the first opening member and the center of the optical opening of the second opening member can be aligned with a straight line parallel to the other straight line mentioned above within the range of machining accuracy of the base and holding part. Therefore, by alternately repeating the optical axis adjustment of the diffracted light while monitoring the intensity of the diffracted light passing through the optical opening of the first opening member and the optical axis adjustment of the diffracted light while monitoring the intensity of the diffracted light passing through the optical opening of the second opening member, the optical axis of the diffracted light passing through the optical opening of the first opening member and the second opening member can be aligned with a straight line.

[0016] The result of these two adjustments is that the optical axis of the laser beam output from the laser source through the lens and the optical axis of the diffracted light passing through the optical openings of the first and second opening members via the corner reflector are both aligned with straight lines. Thus, the position and direction of the output light can be easily adjusted according to this optical assembly. Furthermore, when the two aligned straight lines are parallel to each other (i.e., the third direction is the opposite of the first direction), the above adjustments ensure that the reflecting surface of the reflective diffraction grating is orthogonal to the reflecting surface of the mirror, achieving a fixed position and direction of the output light when the wavelength of the output light (diffracted light) is selected by rotating the corner reflector using the first mechanism. Therefore, a structure that fixes the position and direction of the output light when selecting the wavelength of the output light can be easily realized.

[0017] In the optical kit of the present invention, the first opening member holding portion and the lens holding portion may also be arranged along the second direction. In this way, the space between the laser source's exit surface and the corner reflector can be effectively utilized.

[0018] In the optical kit of the present invention, the structure can also be as follows: the laser source includes a laser element for oscillating the laser; and a cooling section disposed on the laser element on the opposite side of the laser emission surface for cooling the laser element, wherein the second opening member holding section is located in the third direction on the opposite side of the reflector holding section, closer to the cooling section than the cooling section. In this case, the distance between the first opening member and the second opening member can be more reliably ensured, while simultaneously suppressing the influence of heat dissipation from the cooling section on the optical axis adjustment performed using the second opening member.

[0019] In the optical kit of the present invention, the structure may also be as follows: the first mechanism can adjust the optical axis of the diffracted light by holding the reflective diffraction grating and the mirror independently of each other about a rotation axis along the principal surface. In this way, the optical axis of the diffracted light can be adjusted by holding the reflective diffraction grating and the mirror independently of each other about a rotation axis along the principal surface.

[0020] In the optical kit of the present invention, the structure may also include a third mechanism in which the reflector holding part further includes a third mechanism that holds the reflective diffraction grating in a manner that prevents it from rotating along the principal plane, and holds the mirror in a manner that allows the mirror to rotate independently along the principal plane. In this case, the optical axis of the diffracted light from the mirror can be adjusted while suppressing changes in the wavelength of the diffracted light that are not intended to be altered.

[0021] In the optical kit of the present invention, the reflector holding part may further include a fourth mechanism that holds the corner reflector movable along the second direction. In this case, the degree of freedom for adjusting the optical axis of the diffracted light emitted from the corner reflector can be increased.

[0022] The optical kit of the present invention may further include a light source holding part for holding the laser source. In this case, when exchanging laser sources, it is easy to position the laser source and easy to align the light emission point of the laser source with the center of the lens.

[0023] The optical device of the present invention includes the aforementioned optical assembly, a lens held in a lens holding portion, a corner reflector held in a reflector holding portion, a first opening member held in a first opening member holding portion, a second opening member held in a second opening member holding portion, and a third opening member held in a third opening member holding portion. Based on this optical device, for the reasons described above, the position and direction of the output light can be easily and with high precision adjusted.

[0024] Another optical device of the present invention is an optical device constituting an optical system comprising an external resonator of a laser source that outputs laser light, comprising: a light source holding portion disposed on a predetermined surface of the optical device for holding the laser source; and a holding portion disposed on the predetermined surface for holding the optical system, the optical system comprising: a corner reflector comprising a reflective diffraction grating and a mirror, the reflective diffraction grating reflecting the 0th order diffracted light from the laser source incident in a first direction to a second direction intersecting the first direction, the mirror reflecting the diffracted light from the reflective diffraction grating to a third direction different from the first and second directions; and an optical opening formed in which the diffracted light from the corner reflector passes sequentially. The first and second opening members arranged in the third direction have a holding portion comprising: a reflector holding portion for holding the corner reflector; a first opening member holding portion for holding the first opening member; and a second opening member holding portion for holding the second opening member. The reflector holding portion includes, in each of the reflective diffraction grating and the mirror, a first mechanism capable of adjusting the optical axis of the diffracted light. The first opening member holding portion is located in the third direction closer to the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion, and the second opening member holding portion is located in the third direction closer to the opposite side of the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion. Based on this optical device, for the reasons described above, the position and direction of the output light can be easily and with high precision adjusted.

[0025] The effects of the invention

[0026] According to the present invention, it is possible to provide an optical kit and optical device that allows for easy adjustment of the position and direction of the output light. Attached Figure Description

[0027] Figure 1 This is a schematic top view showing the laser device of this embodiment.

[0028] Figure 2 yes Figure 1 A schematic side view of the laser device shown.

[0029] Figure 3 It means Figure 1 , 2 The diagram shows an example of the structure of a laser source.

[0030] Figure 4 It means Figure 2 A three-dimensional view of one retaining part is shown.

[0031] Figure 5 This is a top view illustrating the various steps of the optical axis adjustment method.

[0032] Figure 6 This is a top view illustrating the various steps of the optical axis adjustment method.

[0033] Figure 7 This is a top view illustrating the various steps of the optical axis adjustment method.

[0034] Figure 8 This is a top view illustrating the various steps of the optical axis adjustment method.

[0035] Figure 9 This is a graph showing an example of the result of using the optical kit of this embodiment to perform the optical axis adjustment method described above.

[0036] Figure 10 This is a graph showing an example of the result of using the optical kit of this embodiment to perform the optical axis adjustment method described above.

[0037] Figure 11 This is a graph showing an example of the result of using the optical kit of this embodiment to perform the optical axis adjustment method described above.

[0038] Figure 12 This is a top view used to illustrate a variation. Detailed Implementation

[0039] Hereinafter, an embodiment will be described in detail with reference to the accompanying drawings. Furthermore, in the drawings, the same reference numerals are sometimes used to denote the same elements or equivalent elements, omitting repeated descriptions. Additionally, in the drawings, a rectangular coordinate system defined by the X-axis, Y-axis, and Z-axis is sometimes indicated.

[0040] Figure 1 This is a schematic top view showing the laser device of this embodiment. Figure 2 yes Figure 1 A schematic side view of the laser device shown. Figure 1 , 2 As shown, the laser device (optical device) 100 includes a laser source 101, a lens 102, a corner reflector 103, a variable aperture (third aperture member) 106, a variable aperture (first aperture member) 107, and a variable aperture (second aperture member) 108. The corner reflector 103 includes a reflective diffraction grating 104 and a mirror 105. Additionally, in Figure 2 In order to facilitate the explanation of the positional relationship between the variable aperture 107 and the holding part 17 (described later) and the variable aperture 108 and the holding part 18 (described later), the lens 102 and the holding part 12 (described later), which overlap with the variable aperture 107 and the holding part 17, are shown in dashed lines.

[0041] In the laser device 100, there are defined lines S1, S2, and S3. Lines S1, S2, and S3 are imaginary lines. Lines S1, S2, and S3 are parallel to each other when viewed from the X-axis (the negative direction is the second direction) and the Y-axis. Lines S1 to S3 are along the Z-axis (the positive direction is the first direction, and the negative direction is the third direction). Lines S1 and S2 are equidistant from line S3. In other words, line S3 passes between lines S1 and S2.

[0042] The laser source 101 is not particularly limited, but can be exemplified as a quantum cascade laser. The laser source 101 outputs laser L1. The wavelength of laser L1 is, for example, 3 μm to 15 μm. Lens 102 inputs the laser L1 output from the laser source 101 in the positive Z-axis direction (first direction) and collimates it. In the case of the laser source 101 being the aforementioned quantum cascade laser, lens 102 is, for example, an aspherical lens made of ZnSe or Ge. As an example, a low-reflection coating is applied to the surface of lens 102 on the side of the laser source 101 and the surface on the opposite side. The emission point of the laser source 101 and the center point of lens 102 are substantially coincident, located on a straight line S1.

[0043] Laser L1 emitted from lens 102 is incident on corner reflector 103. Laser L1 incident on corner reflector 103 is then incident on reflective diffraction grating 104. That is, the reflective diffraction grating receives laser L1 emitted from laser source 101 from the positive Z-axis direction (first direction). The incident position of laser L1 on reflective diffraction grating 104 is at the reflecting surface 104s of reflective diffraction grating 104 (refer to...). Figure 4 The intersection of the line S1 and the reflection surface 104s. Furthermore, as an example, the angle of incidence (the angle formed by the perpendicular line from the line S1 to the reflection surface 104s) of the laser L1 is 30°. The number of grooves per unit length and the shape of the grooves in the reflective diffraction grating 104 can be appropriately set according to the oscillation wavelength of the laser source 101. In the case where the laser source 101 is the aforementioned quantum cascade laser, for example, the number of grooves per 1 mm can be 150, and the blaze wavelength can be 6 μm.

[0044] The 0th-order diffracted light L2 of the laser L1 incident on the reflective diffraction grating 104 (the component that exits from the reflecting surface 104s at the same exit angle as ordinary plane reflection and is not affected by wavelength dispersion caused by the diffraction grating), that is, the diffracted light L2 of the laser L after passing through the lens 102, is reflected in the negative X-axis direction (the second direction). In other words, the reflective diffraction grating 104 diffracts the laser L1 incident in the positive Z-axis direction and reflects the 0th-order diffracted light L2 in the negative X-axis direction. The 1st-order diffracted light L3 of the laser L1 incident on the reflective diffraction grating 104 is diffracted in the negative Z-axis direction (the third direction) and enters the lens 102, where it is focused and coupled to the exit end face of the laser L1 of the laser source 101. Thus, an external resonator is formed between the laser source 101 and the reflective diffraction grating 104. In other words, the reflective diffraction grating 104 diffracts the laser L1 incident from the positive Z-axis direction and directs the first-order diffracted light L3 toward the negative Z-axis direction.

[0045] The diffracted light L2, reflected in the negative X-axis direction by the reflective diffraction grating 104, is incident on the reflecting mirror 105. The incident position of the diffracted light L2 on the reflecting mirror 105 is at the reflecting surface 105s of the reflecting mirror 105 (reference). Figure 4 The intersection of the reflective surface 104s of the reflective diffraction grating 104 and the reflective surface 105s of the mirror 105 is orthogonal to each other. The mirror 105 only needs to have a reflectivity of more than 90% for the light output from the laser source 101. As an example, a flat gold mirror with gold deposited on its surface can be used as the mirror 105. The diffracted light L2 incident on the mirror 105, that is, the diffracted light L2 from the reflective diffraction grating 104, is reflected in the negative Z-axis direction (the third direction).

[0046] The diffracted light L2 reflected by mirror 105, i.e., the diffracted light L2 from corner reflector 103, passes sequentially through the optical openings 107h and 108h of variable aperture 107 and variable aperture 108, respectively. That is, variable apertures 107 and 108 are arranged in the negative Z-axis direction such that the diffracted light L2 from corner reflector 103 passes through the optical openings 107h and 108h sequentially. The optical openings 107h and 108h of variable aperture 107 and 108 are opposite each other along the Z-axis direction (along the first and third directions). Variable apertures 106 to 108 are optical components whose aperture (size of the optical opening) can be adjusted by means of the aperture, and they can be the same or different. However, the minimum aperture diameter of variable apertures 106 to 108, with the intention of limiting the optical axis position of the invisible laser within a certain range, can be at least 1 mm or less.

[0047] Variable apertures 107 and 108 are configured such that the center of optical opening 107h and the center of optical opening 108h are aligned on line S2. Diffracted light L2 emitted from variable aperture 108 is output externally. Variable aperture 106 is configured such that, without corner reflector 103, laser light L1 passing through lens 102 passes through optical opening 106h. The optical openings 106h of lens 102 and variable aperture 106 are opposite each other along the Z-axis direction (along the first and third directions). Variable aperture 106 is configured such that the center of its optical opening 106h is aligned on line S1 with the emission point of laser source 101 and the center of lens 102.

[0048] In the laser device 100, with the above structure, when the wavelength of the output light (diffracted light L2) is changed by rotating the corner reflector 103, the position and direction of the output light remain unchanged.

[0049] The laser device 100 described above, which is another optical system including the laser source 101 and the external resonator of the laser source 101, is composed of an optical assembly 10. Next, the optical assembly used to construct the laser device 100 will be described. The optical assembly 10 includes a base 11 including a main surface 11s and a holding part for holding the aforementioned optical components. The base 11 is flat and integrally formed. Alternatively, a concave-convex structure may be formed on the base 11. In this case, the top surfaces of the multiple protrusions of the concave-convex structure may be multiple main surfaces 11s facing one side. In this case, the multiple surfaces constituting the main surfaces 11s may also be parallel to each other. The holding part includes a holding part (lens holding part) 12 for holding lens 102, a holding part (reflector holding part) 13 for holding corner reflector 103, a holding part (third opening member holding part) 16 for holding variable aperture 106, a holding part (first opening member holding part) 17 for holding variable aperture 107, a holding part (second opening member holding part) 18 for holding variable aperture 108, and a holding part (light source holding part) 19 for holding laser source 101.

[0050] Straight lines S1 to S3 lie in a plane parallel to the main surface 11s of the base 11. In other words, the holding parts 12, 16 to 18, and 19 hold the lens 102, the variable apertures 106 to 108, and the laser source 101 at a height equal to the main surface 11s of the center of the lens 102, the center of the optical openings 106h to 108h, and the light-emitting point of the laser source 101. The holding parts 12 and 16 are arranged along the Z-axis direction (along the first and third directions). The holding parts 17 and 18 are arranged along the Z-axis direction (along the first and third directions). The holding parts 16 to 18 can also be identical to each other. Furthermore, the heights from the main surface 11s of the holding parts 16 to 18 can also be the same to each other. In this case, since the holding parts 16 to 18 are identical (of the same height), as long as variable apertures (opening members) of the same shape are used, the height of the center of the optical opening can be easily made consistent within the range of machining accuracy.

[0051] Here, the holding part 17 (and the variable aperture 107) is located in the negative Z-axis direction, closer to the holding part 13 than the emission surface 101s of the laser L1 of the laser source 101 held by the holding part 19. Furthermore, the holding part 18 (and the variable aperture 108) is located in the negative Z-axis direction, closer to the opposite side of the holding part 13 than the emission surface 101s of the laser L1 of the laser source 101 held by the holding part 19. That is, when viewed from the X-axis direction, the holding part 17 (and the variable aperture 107), the emission surface 101s, and the holding part 18 (variable aperture 108) are arranged sequentially in the negative Z-axis direction.

[0052] Furthermore, the holding part 12 (and lens 102) is disposed between the exit surface 101s and the holding part 13 (corner reflector 103). Moreover, the holding part 12 (and lens 102) and the holding part 17 (and variable aperture 107) are arranged along the X-axis direction. That is, when viewed from the X-axis direction, the holding part 12 (lens 102) and the holding part 17 (and variable aperture 107) are arranged to overlap each other.

[0053] Figure 3 It means Figure 1 , 2 The diagram shows an example of the structure of a laser source. Figure 3As shown, the laser source 101 includes a laser element 110 for oscillating the laser, a mounting substrate 120 for mounting the laser element 110, a bottom wall portion 130 disposed on the mounting substrate 120, a cover member 150 disposed on the bottom wall portion 130 to form a sealed package P together with the laser element 110 and the mounting substrate 120, and a cooling element 140 disposed within the package P between the bottom wall portion 130 and the mounting substrate 120. The laser element 110 is, for example, a quantum cascade laser. The cooling element 140 is used to cool the laser element 110, for example, a Peltier element. One end face 110s of the laser element 110 is the emission surface 101s of the laser L1. However, in the package P, a window portion 155 for transmitting the laser L1 is formed in the cover member 150. Therefore, the outer surface 155s of the window portion 155 facing the package P can be the emission surface 101s of the laser L1.

[0054] The laser source 101 is further held in place by a retaining base 130. This includes, for example, an L-shaped support 160 (e.g., a portion of the retaining portion 19). Furthermore, the laser source 101 also includes a heat dissipation device 170 disposed on the support 160 opposite to the base 130, and a fan 180 mounted on the heat dissipation device 170. The heat dissipation device 170 is, for example, air-cooled. The heat dissipation device 170 and the fan 180 are disposed on the laser element 110 opposite to the emission surface 101s of the laser L1, functioning as a cooling unit for cooling the laser element 110. Figure 1 , 2 As shown, the retaining part 18 (variable aperture 108) is located on the opposite side (outer side) of the retaining part 13 (corner reflector 103) in the negative Z direction, which is closer to the cooling part.

[0055] Figure 4 It means Figure 2 A perspective view of the retaining part (for the corner reflector) is shown. Figure 4 As shown, the holding part 13 rotatably holds the entire corner reflector 103, and independently and rotatably holds the reflective diffraction grating 104 and the mirror 105. More specifically, the holding part 13 has a mechanism (second mechanism) 21 that allows the entire corner reflector 103 to be rotatably held about a rotation axis A1 (i.e., along the main surface 11s) that intersects (orthogonally) the main surface 11s of the base 11. The rotation axis A1 passes through the right-angle intersection point C1 of the extension line of the reflecting surface 104s of the reflective diffraction grating 104 and the extension line of the reflecting surface 105s of the mirror 105.

[0056] Furthermore, the holding part 13 has a mechanism (first mechanism) 22 that holds the reflective diffraction grating 104 so that it can rotate independently about a rotation axis A2 along the principal surface 11s and the reflecting surface 104s, and holds the reflector 105 so that it can rotate independently about a rotation axis A3 along the principal surface 11s and the reflecting surface 105s. Thus, mechanism 22 can adjust the optical axis of the diffracted light L2 in the reflective diffraction grating 104 and the reflector 105 respectively. Further, the holding part 13 has a mechanism (third mechanism) 23 that holds the reflective diffraction grating 104 so that it does not rotate independently about the principal surface 11s, and holds the reflector 105 so that it can rotate independently about a rotation axis A4 (i.e., along the principal surface 11s) that intersects (orthogonalizes) the principal surface 11s and along the reflecting surface 105s.

[0057] Furthermore, the grooves of the reflective diffraction grating 104 extend in a direction intersecting (orthogonal) with the main surface 11s and are arranged along the main surface 11s. That is, mechanism 21 holds the reflective diffraction grating 104 so that it can be rotated in the wavelength-selective direction, and mechanism 23 holds the reflective diffraction grating 104 in a manner that prevents it from rotating independently in the wavelength-selective direction. In addition, the holding part 13 may further include, for example, a mechanism (fourth mechanism) (not shown) that holds the corner reflector 103 parallel to the X-axis direction (second direction) by being provided on an optical stage or guide rail.

[0058] Next, the method for adjusting the optical axis of the laser device 100 using the optical kit 10 described above will be explained. Figures 5-8 This is a top view illustrating the various steps of the optical axis adjustment method. Figure 5 This represents the initial state of the method. In this method, firstly, as... Figure 5 As shown, each holding part in the holding part, except for the holding part 13 for the corner reflector 103, holds each optical component other than the corner reflector 103 in the optical system described above. At this time, each holding part holds each optical component in such a way that, within the range of machining accuracy, the center of the lens 102 is aligned with the center of the optical opening 106h of the variable aperture 106 on a straight line S1, and the center of the optical opening 107h of the variable aperture 107 is aligned with the center of the optical opening 108h of the variable aperture 108 on a straight line S2.

[0059] Furthermore, the distances between lens 102 and variable aperture 106, and between variable aperture 107 and variable aperture 108, ensure that the inclination of the straight lines S1 and S2 connecting the centers of lens 102 and variable aperture 106, and the straight lines connecting the centers of variable aperture 107 and variable aperture 108, is suppressed to within 1 mrad. For example, when the aperture diameter of variable apertures 106-108 is 1 mm, the distances between lens 102 and variable aperture 106, and between variable aperture 107 and variable aperture 108, can be at least 80 mm, for example, 90 mm. By making the distances between lens 102 and variable aperture 106, and between variable aperture 107 and variable aperture 108, 80 mm or more, the inclination of the straight lines S1 and S2 connecting their respective centers is suppressed to within 1 mrad. Furthermore, the distance between straight lines S1 and S2 has no upper limit as long as the optical components do not interfere with each other when they are arranged on straight lines S1 and S2. However, in order to avoid the enlargement of the optical system and the expansion of the beam misalignment caused by the rotation of the reflective diffraction grating 104 (described later), it can be set to within 100mm, for example, 40mm.

[0060] Next, in this method, such as Figure 6 As shown, the laser source 101 is maintained in the holding portion 19 while the corner reflector 103 is not installed. The laser source 101 is configured such that the output laser L1 passes through the optical opening 106h of the variable aperture 106 held in the holding portion 16 via the lens 102 held in the holding portion 12. Furthermore, a detector 50 capable of detecting the light intensity of the laser L1 after passing through the optical opening 106h is provided at a position on the variable aperture 106 opposite to the laser source 101.

[0061] Furthermore, the position of the laser source 101 relative to the lens 102 is adjusted by monitoring the light intensity of the laser L1 after it passes through the optical opening 106h of the variable aperture 106 and simultaneously obtaining the maximum value of that light intensity. This achieves alignment between the emission point of the laser source 101 and the center of the lens 102. The center of the lens 102 and the center of the optical opening 106h of the variable aperture 106 can be aligned with a straight line S1 within the range of machining accuracy of the base 11 and the holding part.

[0062] Through the above steps, the optical axis of the laser L output from the laser source 101 and passing through the lens 102 is aligned with the straight line S1. However, at this stage, the distance between the laser source 101 and the lens 102 is not optimal. To monitor the light intensity at this stage, the distance between the laser source 101 and the lens 102 can be adjusted so that the laser L1 is focused near the variable aperture 106.

[0063] Next, in this method, such as Figure 7 As shown, the corner reflector 103 is held in the holding part 13. Here, the reflecting surface 104s of the reflective diffraction grating 104 and the reflecting surface 105s of the mirror 105 are approximately orthogonal at the viewing level. The strict orthogonality of the reflecting surface 104s and the reflecting surface 105s is ensured by performing subsequent processes, as described later. Furthermore, at this time, the incident angle of the laser L1 towards the reflecting surface 104s can be set to the angle at which the external resonator between the reflecting surface 104s and the laser source 101 is established, that is, the angle at which the first-order diffracted light L3 is fed back to the laser source 101 via the lens 102. As mentioned above, at this stage, the distance between the laser source 101 and the lens 102 is not optimal. Therefore, although the external resonance is not established, the light output of the laser source 101 is improved by causing a portion of the returned light from the reflective diffraction grating 104 to return to the laser source 101.

[0064] On the other hand, a detector 50 is provided on the opposite side of the variable aperture 107 from the corner reflector 103, capable of detecting the intensity of the diffracted light L2 after passing through the optical opening 107h. Furthermore, by monitoring the intensity of the diffracted light L2 after passing through the optical opening 107h (e.g., sufficiently reduced to less than 1 mm) of the variable aperture 107 via the corner reflector 103, and simultaneously obtaining the maximum value of that intensity, the angle of the reflective diffraction grating 104 is adjusted using the mechanism 22 of the holding part 13, thereby adjusting the optical axis of the diffracted light L2 from the reflective diffraction grating 104. At this time, by using the fourth mechanism to move the entire corner reflector 103 along the X-axis direction, the optical axis of the diffracted light L2 can be further adjusted.

[0065] Next, as Figure 8 As shown, once the maximum intensity of the diffracted light L2 after passing through the optical opening 107h of the variable aperture 107 is obtained, the optical opening 107h of the variable aperture 107 is sufficiently enlarged, and a detector 50 capable of detecting the intensity of the diffracted light L2 after passing through the optical opening 108h is provided at a position opposite to the variable aperture 107 on the variable aperture 108. Moreover, by monitoring the intensity of the diffracted light L2 after passing through the optical opening 108h of the variable aperture 108 (for example, sufficiently reduced to less than 1 mm) via the corner reflector 103, and simultaneously obtaining the maximum intensity of that light, the angle of the reflector 105 is adjusted using the mechanisms 22 and 23 of the holding part 13, thereby adjusting the optical axis of the diffracted light L2 from the reflector 105.

[0066] The center of the optical opening 107h of the variable aperture 107 and the center of the optical opening 108h of the variable aperture 108 can be aligned with the straight line S2 within the range of machining accuracy of the base 11 and the holding part. Therefore, by alternately repeating the optical axis adjustment of the diffracted light L2 after monitoring the intensity of the diffracted light L2 after passing through the optical opening 107h of the variable aperture 107 and the optical axis adjustment of the diffracted light L2 after monitoring the intensity of the diffracted light L2 after passing through the optical opening 108h of the variable aperture 108, the optical axis of the diffracted light L2 passing through the optical openings 107h and 108h of the variable apertures 107 and 108 can be aligned with the straight line S2.

[0067] As a result of these adjustments, the optical axis of the laser L1 output from the laser source 101 through the lens 102 and the optical axis of the diffracted light L2 passing through the optical openings 107h and 108h of the variable apertures 107 and 108 via the corner reflector 103 are aligned with two parallel straight lines S1 and S2. Furthermore, this ensures that the reflecting surface 104s of the reflective diffraction grating 104 is orthogonal to the reflecting surface 105s of the mirror 105, thus fixing the position and direction of the output light when the wavelength of the output light (diffracted light L2) is selected by rotating the corner reflector 103 using mechanism 21.

[0068] Finally, in this method, the distance between the laser source 101 and the lens 102 is adjusted so that the light intensity of the diffracted light L2 passing through the optical opening 108h after passing through the optical opening 108h is maximized at any distance from the variable aperture 108. As a result, the laser L1 from the laser source 101 is collimated by the lens 102, and the laser source 101 is optically coupled to the reflective diffraction grating 104, thus establishing external resonance at one end of the reflective diffraction grating 104 as a resonator. According to this method, after setting the laser source 101, the optical axis adjustment of the external resonator can be completed by simply passing light through the variable apertures 106 to 107 in sequence.

[0069] As explained above, the position and direction of the output light can be adjusted using the optical kit 10 as follows: First, the corner reflector 103 is held in the holding part 13. Then, the optical axis of the diffracted light L2 from the reflective diffraction grating 104 is adjusted using the mechanism 22 in a manner that monitors the light intensity of the diffracted light L2 passing through the optical opening 107h of the variable aperture 107 via the corner reflector 103 and simultaneously obtains the maximum value of that light intensity. Once the maximum value of the light intensity of the diffracted light L2 after passing through the optical opening 107h of the variable aperture 107 is obtained, the optical opening 107h of the variable aperture 107 is sufficiently enlarged, or after temporarily removing the variable aperture 107, the optical axis of the diffracted light L2 from the mirror 105 is adjusted using the mechanism 22 in a manner that monitors the light intensity of the diffracted light L2 passing through the optical opening 108h of the variable aperture 108 via the corner reflector 103 and simultaneously obtains the maximum value of that light intensity. The center of the optical opening 107h of the variable aperture 107 and the center of the optical opening 108h of the variable aperture 108 can be aligned with the straight line S2 within the range of machining accuracy of the base 11 and the holding parts 17 and 18. Therefore, by alternately repeating the optical axis adjustment of the diffracted light L2 after monitoring the intensity of the diffracted light L2 after passing through the optical opening 107h of the variable aperture 107 and the optical axis adjustment of the diffracted light L2 after monitoring the intensity of the diffracted light L2 after passing through the optical opening 108h of the variable aperture 108, the optical axis of the diffracted light L2 passing through the optical openings 107h and 108h of the variable aperture 107 and the variable aperture 108 can be aligned with this straight line.

[0070] As a result of these adjustments, the optical axis of the diffracted light L2 output from the laser source 101, passing through the corner reflector 103 and the optical openings 107h and 108h of the variable apertures 107h and 108h of the variable apertures 107h and 108h, is aligned with the straight line S2. This achieves a fixed position and direction of the output light. Thus, the position and direction of the output light can be easily adjusted according to the optical assembly 10. Specifically, in the optical assembly 10, the holding part 17 (variable aperture 107) is located closer to the holding part 13 than the emission surface 101s of the laser L1 held by the holding part 19, and the holding part 18 (variable aperture 108) is located on the opposite side, closer to the holding part 13 than the emission surface 101s. That is, the distance between the variable apertures 107 and 108 is ensured in the optical assembly 10. Therefore, it is possible to suppress the tilt of the optical axis (the straight line) of the diffracted light L2 passing through both the optical opening 107h of the variable aperture 107 and the optical opening 108h of the variable aperture 108, and adjust the position and direction of the output light with higher precision.

[0071] Furthermore, in the optical kit 10, the optical system includes a lens 102 and a variable aperture 106. The lens 102 is disposed between the laser source 101 and the corner reflector 103, and laser L1 is input in the positive Z-axis direction. The variable aperture 106 is configured to form an optical opening 106h that allows laser L1 to pass through after passing through the lens 102 without the corner reflector 103. Laser L1 passing through the lens 102 is incident on the reflective diffraction grating 104. The holding part has a holding part 12 for holding the lens 102 and a holding part 16 for holding the variable aperture 106. The holding part 13 includes a mechanism 21 that allows the entire corner reflector 103 to be rotatably held along the main surface.

[0072] Therefore, the position and direction of the output light can be adjusted as follows: First, all optical components in the optical system, except for the corner reflector 103, are held in each holding part except for the holding part 13. Furthermore, the laser source 101 is positioned such that the laser L1 output from the laser source 101 passes through the lens 102 held in the holding part 12 and through the optical opening 106h of the variable aperture 106 held in the holding part 16. Next, the position of the laser source 101 relative to the lens 102 is adjusted such that the maximum intensity of the laser L1 passing through the optical opening 106h of the variable aperture 106 is obtained while monitoring the intensity of that intensity. This achieves alignment between the emission point of the laser source 101 and the center of the lens 102. The center of the lens 102 and the center of the optical opening 106h of the variable aperture 106 are aligned with the straight line S1 within the range of machining accuracy of the base 11 and the holding part 16. Therefore, through the above-described process, the optical axis of the laser L1 output from the laser source 101 through the lens 102 can be aligned with the straight line S1.

[0073] Subsequently, as described above, by adjusting the variable aperture 107 and variable aperture 108, the optical axis of the diffracted light L2 passing through the optical openings 107h and 108h of the variable aperture 107 and variable aperture 108 can be aligned with the straight line S2.

[0074] The result of these two adjustments is that the optical axis of the laser L1 output from the laser source 101 through the lens is aligned with the optical axis of the diffracted light L2 passing through the optical openings 107h and 108h of the variable apertures 107 and 108 via the corner reflector 103, and these alignments are two parallel straight lines S1 and S2. This ensures that the reflecting surface 104s of the reflective diffraction grating 104 is orthogonal to the reflecting surface 105s of the mirror 105, thus fixing the position and direction of the output light when the wavelength of the output light (0th order diffracted light) is selected by rotating the corner reflector 103 using mechanism 21. Therefore, with this optical assembly 10, the position and direction of the output light can be easily adjusted, and a structure that easily fixes the position and direction of the output light when selecting the wavelength can be easily achieved.

[0075] Furthermore, in the optical kit 10, the holding part 17 (variable aperture 107) and the holding part 12 (lens 102) are arranged along the X-axis. In this way, the space between the emission surface 101s of the laser source 101 and the corner reflector 103 can be effectively utilized.

[0076] Furthermore, in the optical kit 10, the laser source 101 includes a laser element 110 that oscillates the laser L1, and a cooling section (heat dissipation device 170 and fan 180) disposed on the laser element 110 on the adsorption side of the laser L1 with the emission surface 101s for cooling the laser element 110. Moreover, the holding section 18 (variable aperture 108) is located on the opposite side of the holding section 13 (corner reflector 103) in the negative Z-axis direction (third direction), closer to it than the cooling section. Therefore, the distance between the variable apertures 107 and 108 can be more reliably ensured, while simultaneously suppressing the influence of heat dissipation from the cooling section on the optical axis adjustment performed using the variable aperture 108.

[0077] Furthermore, in the optical kit 10, the mechanism 22 can adjust the optical axis of the diffracted light L2 by holding the reflective diffraction grating 104 and the mirror 105 in a manner that allows them to rotate independently about the rotation axis along the principal surface 11s. Therefore, by holding the reflective diffraction grating 104 and the mirror 105 in a manner that allows them to rotate independently about the rotation axis along the principal surface 11s, the optical axis of the diffracted light L2 can be adjusted.

[0078] Furthermore, in the optical assembly 10, the holding part 13 also includes a mechanism 23 that holds the reflective diffraction grating 104 in a manner that prevents it from rotating along the principal surface 11s, and holds the mirror 105 in a manner that allows the mirror 105 to rotate independently along the principal surface 11s. In this case, it is possible to suppress unintended changes in the wavelength of the diffracted light L2 and simultaneously adjust the optical axis of the diffracted light L2 from the mirror 105.

[0079] Furthermore, in the optical kit 10, the holding part 13 may also include a fourth mechanism that holds the corner reflector 103 movable along the X-axis. In this case, the degree of freedom for adjusting the optical axis of the diffracted light L3 emitted from the corner reflector 103 is improved.

[0080] Furthermore, in the above structure, in order to prevent the change in the angle of the reflective diffraction grating 104, i.e. the angle of the corner reflector 103, from causing misalignment of the optical axis of the diffracted light L2 after being reflected by the mirror 105, it is necessary to make the reflective diffraction grating 104 and the reflecting surfaces 104s and 105s of the mirror 105 perpendicular to each other, and to make the rotation center (position of rotation axis A1) of the corner reflector 103 positioned at a distance equal to that of the straight lines S1 and S2.

[0081] However, these conditions are naturally established as a result of the aforementioned optical axis adjustment method for aligning the optical axis with the two parallel straight lines S1 and S2. This allows for the suppression of changes in the position and direction of the beam caused by the rotation of the corner reflector 103 while performing optical axis adjustment and establishing the external resonator simply by following the steps described above. In the aforementioned optical axis adjustment method, the reason for using adjustment mechanisms (mechanisms 22 and 23) to adjust the reflective diffraction grating 104 and the mirror 105 without prior adherence to the strict right angles of the reflecting surfaces 104s and 105s is to absorb minor tilts and misalignments that may occur due to the exchange of the laser source and the diffraction grating, or deviations arising from the machining accuracy determining the position of the lens 102 and the variable apertures 106-108 and the ideal state dependent on the aperture of the variable apertures 106-108, thereby achieving an optical axis along the straight lines S1 and S2.

[0082] Furthermore, even without using the structure described above, by separately forming and assembling a corner reflector in which the reflecting surfaces of the reflective diffraction grating and the mirror are arranged at right angles, a structure is achieved that avoids misalignment of the optical axis of the emitted light due to changes in the angle of the corner reflector. However, adjustments are still needed to absorb the aforementioned tilting and misalignment in order to guide the emitted light to the desired position and direction. The need to form a corner reflector with strict right-angled alignment each time the reflective diffraction grating is exchanged causes significant inconvenience for the user. In other words, in this embodiment, by using the adjustment mechanism of the variable apertures 106-108 and the corner reflector 103 arranged as described above, the convenience of the user's adjustment operation when exchanging the laser source and the diffraction grating can be significantly improved.

[0083] Furthermore, in the optical system of this embodiment, after the laser source and diffraction grating have just been exchanged and realigned, the output light must also be directed along the position and direction of the straight line S2 defined by the variable apertures 107 and 108. Therefore, the optical axis before the exchange can be reproduced after the exchange and accompanying alignment of the optical components. Thus, the laser source and diffraction grating can be exchanged without affecting external optical systems that use the laser device 100 of this embodiment as a wavelength-variable light source. Based on the above description, the optical kit 10 of this embodiment is preferably an optical kit that allows for easy exchange and alignment of optical components such as the laser source and diffraction grating.

[0084] Figures 9-11 This is a graph illustrating an example of the result of performing the optical axis adjustment method described above using the optical kit of this embodiment. Figure 9 In the diagram, the lower horizontal axis represents the wavenumber, the upper horizontal axis represents the wavelength, the left vertical axis represents the normalized light intensity, and the right vertical axis represents the average output. Figure 9 The curves in the graph represent the average output of each light intensity relative to the peak wavelength (wavenumber). Figure 10 It is Figure 9 A magnified portion of the curve. For example... Figure 9 , 10 As shown, according to the optical axis adjustment using the optical kit 10, at distances exceeding 150cm... -1 Within the wavelength (wavenumber) range, it is possible to achieve a full width at half maximum (FWHM) of less than 1 cm. -1 A laser device 100 that allows for flexible selection of oscillation wavelengths in a single mode.

[0085] exist Figure 11 In the diagram, the horizontal axis represents the wavenumber, and the vertical axis represents the deviation of the center of the output light in the X and Y directions. For example... Figure 11 As shown, by adjusting the optical axis using the optical kit 10, a distance of over 150cm can be achieved. -1 When selecting a wavelength within a certain wavelength (wavenumber) range, a laser device 100 can be achieved where the output light misalignment is suppressed to within 0.5 mrad in both the X-axis and Y-axis directions. Thus, using this optical kit 10, an external resonator light source can be provided that is preferably used in precise measurements such as beam splitting.

[0086] The above embodiments are used to illustrate an example of the present invention. Therefore, the present invention is not limited to the optical kit 10 and laser device 100 described above, and can be arbitrarily modified.

[0087] For example, the holding part 17 and the variable aperture 107 are positioned as close as possible to the corner reflector 103 (mirror 105) side to ensure that the distance between the variable aperture 107 and the variable aperture 108 is as long as possible. However, when the corner reflector 103 is rotated about the rotation axis A1 using the mechanism 21, it is necessary to ensure that the mirror 105 does not interfere with the holding part 17 and the variable aperture 107. Similarly, when the corner reflector 103 is rotated about the rotation axis A1, it is necessary to ensure that the reflective diffraction grating 104 does not interfere with the holding part 12 and the lens 102.

[0088] Based on this situation, referring to Figure 12 The case where the holding part 12 and lens 102 are closest to the corner reflector 103 is explored. The incident angle θi of the laser L1 incident on the reflective diffraction grating 104 is set to be 25° or more and 65° or less. The laser L1 passes through the center of the lens 102 on the straight line S1. On the other hand, when the reflective diffraction grating 104 is to be positioned as close as possible to the end of the base 11, one end of the reflective diffraction grating 104 can be aligned with the intersection point C1 (the rotation center of the reflective diffraction grating 104) on the straight line S3. In this case, in order for the reflective diffraction grating 104 to receive the incident laser L1, the reflective diffraction grating 104 needs to extend in the positive X-axis direction by a length corresponding to the distance D2 between the straight lines S1 and S3, with the other ends reaching the straight line S1. The distance from the intersection point C1 to the intersection point of the reflective diffraction grating 104 and the straight line S1 is calculated using the distance D2 between the straight lines S1 and S3 (half of the distance D1 between the straight lines S1 and S2), which is distance D2 × 1 / cos65°. Furthermore, considering the beam diameter R of the laser L1 collimated by the lens 102 and incident on the reflective diffraction grating 104, the lens 102 can be positioned closer to the corner reflector 103 by setting the length a of the reflective diffraction grating 104 to (distance D2 between the straight lines S1 and S3 + the collimated laser beam diameter R) × 1 / cosθi. The same applies to the reflector 105.

[0089] Furthermore, in the aforementioned laser device, the holding part 13 is not limited to a structure in which the corner reflector 103 is integrally detached and reassembled. The holding part 13 may also hold the reflective diffraction grating 104 in a way that allows the corner reflector 103 to be detached and reassembled only.

[0090] Alternatively, instead of the variable apertures 106-108, an opening component such as a pinhole-type component that does not have an aperture function, i.e., does not have an adjustment function for the size of the optical openings 106h-108h, can be used. In this case, the holding parts 16-18 can hold the pinhole-type component or other opening component in a pluggable manner from the optical path of the laser L1 or the diffracted light L2. That is, the variable apertures 106-108 can be any component capable of forming an optical opening in the optical path of the laser L1 or the diffracted light L2.

[0091] Furthermore, the method for monitoring the intensity of laser L1 or diffracted light L2 during optical axis adjustment can replace the method using detector 50, and there are no particular limitations on using thermosensitive pigments, etc.

[0092] Here, in the above embodiment, an example is given where the first direction, which is the incident direction of the laser L1 directed toward the reflective diffraction grating 104, is the positive Z-axis direction, and the third direction, which is the reflection direction of the diffracted light L2 from the mirror 105, is the negative Z-axis direction. That is, in the example above, the third direction is the opposite of the first direction. In this example, the lines S1 and S2 are parallel to each other and are aligned with the Z-axis direction. However, the third direction can be any direction different from the first and second directions. For example, the third direction (line S2) may include not only a Z-axis component but also an X-axis component; as an example, it may include an X-axis component smaller than the Z-axis component.

[0093] In this case, as long as the intersection point C1 of the extension of the reflecting surface 104s of the reflective diffraction grating 104 and the extension of the reflecting surface 105s of the mirror 105 becomes the rotation axis A1, the position and direction of the output light can be fixed during the wavelength tuning process of the rotating corner reflector 103. Furthermore, although the reflective diffraction grating 104 and the mirror 105 do not form a right angle in this case, they can be arranged at a predetermined angle corresponding to the angle formed by the lines S1 and S2 as described in the above embodiment using the same adjustment method.

[0094] Furthermore, in the above embodiment, as an example of an optical device, a laser device 100 composed of an optical kit 10 is illustrated. However, the optical device is not limited to the structure using the optical kit 10. The optical device may be, for example, a specific laser device, and the aforementioned holding portions 12 to 19 may be provided on a specified surface of any component such as the housing of the specific laser device, and the aforementioned optical components held by the holding portions 12 to 19 may be used to construct an optical system including an external resonator. In this case, it is effective that not only during the replacement of the light source, but also when adjusting the optical components assembled into the device in cases where they have deviated over the years due to the deterioration of the fixture, the position and direction of the output light can be easily and with high precision.

[0095] Industrial availability

[0096] It can provide optical kits and optical devices that allow for easy adjustment of the position and direction of the output light.

[0097] Explanation of reference numerals in the attached figures

[0098] 10 Optical Kits

[0099] 11 bases

[0100] 11s main face

[0101] 12. Holding section (lens holding section)

[0102] 13. Holding section (reflector holding section)

[0103] 16. Retaining part (retaining part for the 3rd opening member)

[0104] 17. Retaining part (retaining part for the first opening member)

[0105] 18. Retaining part (retaining part for the second opening member)

[0106] 19. Holding section (light source holding section)

[0107] Agency 21 (Agency 2)

[0108] 22nd Agency (Agency 1)

[0109] 23rd Agency (The 3rd Agency)

[0110] 100 laser device (optical device)

[0111] 101 laser source

[0112] 110 laser element

[0113] 101s exit surface

Claims

1. An optical kit for constructing an optical system containing an external resonator of a laser source that outputs laser light, wherein, The optical kit includes: The base, which includes the main face; A light source holding part is disposed on the main surface for holding the laser source; and A retaining part, disposed on the main surface, is used to retain the optical system. The optical system includes: A corner reflector, comprising a reflective diffraction grating and a mirror, wherein the reflective diffraction grating diffracts the laser light emitted from the laser source and incident in a first direction, reflecting the 0th order diffracted light in a second direction intersecting the first direction; and the mirror reflects the diffracted light from the reflective diffraction grating in a third direction different from the first and second directions; and The first and second opening members are arranged in the third direction in such a way as to form optical openings through which the diffracted light from the corner reflector passes in sequence. The retaining part has: A reflector holding part for holding the corner reflector; A first opening member retaining portion, which is used to retain the first opening member; and The second opening member retaining part is used to retain the second opening member. The reflector holding part includes a first mechanism capable of adjusting the optical axis of the diffracted light in each of the reflective diffraction grating and the reflector. The first opening member holding portion is located in the third direction at a position closer to the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion. The second opening member holding portion is located in the third direction at a position closer to the opposite side of the reflector holding portion than the emission surface of the laser from the laser source held by the light source holding portion. The optical system includes: A lens, disposed between the laser source and the corner reflector, through which the laser light is input in the first direction; and The third opening member is configured to form an optical opening through which the laser light, after passing through the lens, can pass, in the absence of the corner reflector. The laser light, having passed through the lens, is incident on the reflective diffraction grating. The retaining part has: Lens holding portion, which is used to hold the lens; and The third opening member retaining part is used to retain the third opening member. The reflector holding part includes a second mechanism capable of rotatably holding the entire corner reflector along the main surface. The first opening member holding portion and the lens holding portion are arranged along the second direction.

2. An optical kit for constructing an optical system containing an external resonator of a laser source that outputs laser light, wherein, The optical kit includes: The base, which includes the main face; A light source holding part is disposed on the main surface for holding the laser source; and A retaining part, disposed on the main surface, is used to retain the optical system. The optical system includes: A corner reflector, comprising a reflective diffraction grating and a mirror, wherein the reflective diffraction grating diffracts the laser light emitted from the laser source and incident in a first direction, reflecting the 0th order diffracted light in a second direction intersecting the first direction; and the mirror reflects the diffracted light from the reflective diffraction grating in a third direction different from the first and second directions; and The first and second opening members are arranged in the third direction in such a way as to form optical openings through which the diffracted light from the corner reflector passes in sequence. The retaining part has: A reflector holding part for holding the corner reflector; A first opening member retaining portion, which is used to retain the first opening member; and The second opening member retaining part is used to retain the second opening member. The reflector holding part includes a first mechanism capable of adjusting the optical axis of the diffracted light in each of the reflective diffraction grating and the reflector. The first opening member holding portion is located in the third direction at a position closer to the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion. The second opening member holding portion is located in the third direction at a position closer to the opposite side of the reflector holding portion than the emission surface of the laser from the laser source held by the light source holding portion. The laser source includes: Laser element, which causes the laser to oscillate; and A cooling section, disposed on the laser element on the opposite side of the laser emission surface, is used to cool the laser element. The second opening member holding portion is located in the third direction at a position that is closer to the opposite side of the reflector holding portion than the cooling portion.

3. The optical kit as claimed in claim 1, wherein, The first mechanism is capable of adjusting the optical axis of the diffracted light by holding each of the reflective diffraction grating and the reflector in a position to rotate independently about a rotation axis along the main surface.

4. The optical kit as claimed in claim 2, wherein, The first mechanism is capable of adjusting the optical axis of the diffracted light by holding each of the reflective diffraction grating and the reflector in a position to rotate independently about a rotation axis along the main surface.

5. The optical kit as claimed in any one of claims 1 to 4, wherein, The reflector holding part further includes a third mechanism that holds the reflective diffraction grating in a manner in which the reflective diffraction grating does not rotate along the main surface, and holds the reflector in a manner in which the reflector rotates independently along the main surface.

6. The optical kit as claimed in any one of claims 1 to 4, wherein, The reflector holding part further includes a fourth mechanism capable of moving and holding the corner reflector along the second direction.

7. The optical kit as claimed in claim 5, wherein, The reflector holding part further includes a fourth mechanism capable of moving and holding the corner reflector along the second direction.

8. An optical device, wherein, have: The optical kit according to any one of claims 1 to 7; The laser source is held in the laser source holding part of the light source; The corner reflector is held in the reflector holding portion; The first opening member is held in the first opening member holding portion; and The second opening member is held in the second opening member holding portion.

9. An optical device comprising an external resonator of a laser source that outputs laser light, wherein, The optical device includes: A light source holding part is disposed on a predetermined surface of the optical device for holding the laser source; and A retaining part, disposed on the designated surface, is used to retain the optical system. The optical system includes: A corner reflector, comprising a reflective diffraction grating and a mirror, wherein the reflective diffraction grating diffracts the laser light emitted from the laser source and incident in a first direction, reflecting the 0th order diffracted light in a second direction intersecting the first direction; and the mirror reflects the diffracted light from the reflective diffraction grating in a third direction different from the first and second directions; and The first and second opening members are arranged in the third direction in such a way as to form optical openings through which the diffracted light from the corner reflector passes in sequence. The retaining part includes: A reflector holding part for holding the corner reflector; A first opening member retaining portion, which is used to retain the first opening member; and The second opening member retaining part is used to retain the second opening member. The reflector holding part includes a first mechanism capable of adjusting the optical axis of the diffracted light in each of the reflective diffraction grating and the reflector. The first opening member holding portion is located in the third direction at a position closer to the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion. The second opening member holding portion is located in the third direction at a position closer to the opposite side of the reflector holding portion than the emission surface of the laser from the laser source held by the light source holding portion. The optical system includes: A lens, disposed between the laser source and the corner reflector, through which the laser light is input in the first direction; and The third opening member is configured to form an optical opening through which the laser light, after passing through the lens, can pass, in the absence of the corner reflector. The laser light, after passing through the lens, is incident on the reflective diffraction grating. The retaining part has: Lens holding portion, which is used to hold the lens; and The third opening member retaining part is used to retain the third opening member. The reflector holding part includes a second mechanism capable of rotatably holding the entire corner reflector along the predetermined surface. The first opening member holding portion and the lens holding portion are arranged along the second direction.

10. An optical device comprising an external resonator of a laser source that outputs laser light, wherein, The optical device includes: A light source holding part is disposed on a predetermined surface of the optical device for holding the laser source; and A retaining part, disposed on the designated surface, is used to retain the optical system. The optical system includes: A corner reflector, comprising a reflective diffraction grating and a mirror, wherein the reflective diffraction grating diffracts the laser light emitted from the laser source and incident in a first direction, reflecting the 0th order diffracted light in a second direction intersecting the first direction; and the mirror reflects the diffracted light from the reflective diffraction grating in a third direction different from the first and second directions; and The first and second opening members are arranged in the third direction in such a way as to form optical openings through which the diffracted light from the corner reflector passes in sequence. The retaining part includes: A reflector holding part for holding the corner reflector; A first opening member retaining portion, which is used to retain the first opening member; and The second opening member retaining part is used to retain the second opening member. The reflector holding part includes a first mechanism capable of adjusting the optical axis of the diffracted light in each of the reflective diffraction grating and the reflector. The first opening member holding portion is located in the third direction at a position closer to the reflector holding portion than the laser emission surface of the laser source held by the light source holding portion. The second opening member holding portion is located in the third direction at a position closer to the opposite side of the reflector holding portion than the emission surface of the laser from the laser source held by the light source holding portion. The laser source includes: Laser element, which causes the laser to oscillate; and A cooling section, disposed on the laser element on the opposite side of the laser emission surface, is used to cool the laser element. The second opening member holding portion is located in the third direction at a position that is closer to the opposite side of the reflector holding portion than the cooling portion.

Images