Spectral beam combining device for grating external-cavity semiconductor laser

Abstract

A spectral beam combining device (10) for a grating external-cavity semiconductor laser, said device comprising: a plurality of laser emitting units (11); a first optical path processing unit (12), configured to convert a plurality of laser beams correspondingly outputted by the plurality of laser emitting units (11) into a plurality of first collimated beams (L1) arranged in a first direction (Z), the first direction (Z) being perpendicular to a propagation direction of the first collimated beams (L1); a second optical path processing unit (13), configured to convert the plurality of first collimated beams (L1) into a plurality of second collimated beams (L2) arranged in a second direction (Y), a propagation direction of the second collimated beams (L2) being perpendicular to the propagation direction of the first collimated beams (L1), and the second direction (Y) being perpendicular to the first direction (Z) and the propagation direction of the second collimated beams (L2); and a spectral beam combining unit (14), configured to perform spectral beam combining on the plurality of second collimated beams (L2) using the second direction (Y) as a spectral beam combining direction and to output same, thereby achieving spectral beam combining with high efficiency and high beam quality, enabling the optical axis of a beam combining optical system to be coplanar with the optical axis of a light source, and simplifying assembly and adjustment of the system structure.

Description

Semiconductor laser grating external cavity spectrum beam combining device TECHNICAL FIELD

[0001] The present application relates to the technical field of laser, in particular to a semiconductor laser grating external cavity spectrum beam combining device. BACKGROUND

[0002] Semiconductor lasers have the advantages of wide wavelength coverage range, high electro-optical conversion efficiency, small volume, good stability, low cost, long life, etc., and have wide application prospects in many fields such as military industry, industrial processing, medical and cosmetic, scientific research, etc.

[0003] At present, the commercial single-tube semiconductor laser has the disadvantages of low output power, low spatial brightness and poor beam quality, which limits its direct application. The spectrum beam combining technology based on diffractive optical elements can realize high power while ensuring high beam quality and high efficiency. Theoretically, the beam quality after beam combining is equivalent to that of a single light-emitting unit participating in beam combining. This technology has become a research hotspot at home and abroad in recent years.

[0004] However, the spectrum beam combining device of the semiconductor laser in the prior art has the problems of low spectrum beam combining efficiency and low beam quality. SUMMARY

[0005] The purpose of the present application is to provide a semiconductor laser grating external cavity spectrum beam combining device to improve the efficiency and beam quality of spectrum beam combining.

[0006] The semiconductor laser grating external cavity spectrum beam combining device provided by the embodiments of the present application comprises: a plurality of laser light-emitting units; a first optical path processing unit configured to convert a plurality of beams of laser light corresponding to the output of the plurality of laser light-emitting units into a plurality of beams of first collimated light arranged along a first direction, the first direction being perpendicular to the propagation direction of the first collimated light; a second optical path processing unit configured to convert the plurality of beams of first collimated light into a plurality of beams of second collimated light arranged along a second direction, the propagation direction of the second collimated light being perpendicular to the propagation direction of the first collimated light, and the second direction being perpendicular to the first direction and the propagation direction of the second collimated light; and a spectrum beam combining unit configured to perform spectrum beam combining on the plurality of beams of second collimated light with the second direction as the spectrum beam combining direction and output.

[0007] In the semiconductor laser grating external cavity spectrum beam combining device, the optical path experienced by the laser corresponding to the output of each laser light-emitting unit to the second optical path processing unit is equal.

[0008] The plurality of laser light emitting units are arranged in sequence along a third direction, an included angle between the third direction and the first plane is an acute angle, and an included angle between the third direction and the second plane is an acute angle, wherein the first plane is a plane in which the plurality of first collimated lights are located, and the second plane is a plane in which the plurality of second collimated lights are located.

[0009] The second light path processing unit includes a half-wave plate and a rotating mirror, the half-wave plate is configured to rotate the polarization direction of each of the plurality of first collimated lights by 90 degrees and output to the rotating mirror, and the rotating mirror is configured to change the arrangement mode of the plurality of first collimated lights whose polarization direction is rotated by 90 degrees from the first direction to the second direction.

[0010] The rotating mirror includes a first reflecting surface and a second reflecting surface, and each of the plurality of first collimated lights whose polarization direction is rotated by 90 degrees is reflected by the first reflecting surface and the second reflecting surface in sequence and output as the corresponding second collimated light.

[0011] The spectral beam combining unit includes a lens unit, a grating unit and a feedback unit, the lens unit is configured to converge the plurality of second collimated lights and respectively input them on the grating unit at different angles, the grating unit is configured to select the laser light of the corresponding target wavelength from each of the plurality of second collimated lights, each of the plurality of second collimated lights corresponds to a different target wavelength, and the feedback unit is configured to return part of the laser light of each target wavelength to the corresponding laser light emitting unit along the original light path and output the remaining laser light of each target wavelength.

[0012] The spectral beam combining unit further includes a filter unit, the filter unit is configured to respectively increase the divergence angle of the laser light of each target wavelength output by the grating unit and output to the feedback unit.

[0013] The filter unit includes a convex lens and a concave lens, the laser light of each target wavelength output by the grating unit is respectively converged on the concave lens through the convex lens and is diverged through the concave lens and output to the feedback unit.

[0014] The first light path processing unit includes a plurality of fast-axis collimating mirrors, a plurality of slow-axis collimating mirrors and a plurality of reflecting mirrors, each laser light emitting unit corresponds to one fast-axis collimating mirror, one slow-axis collimating mirror and one reflecting mirror, and the laser light output by each laser light emitting unit is sequentially fast-axis collimated, slow-axis collimated and reflected by the corresponding fast-axis collimating mirror, slow-axis collimating mirror and reflecting mirror and output as the corresponding first collimated light.

[0015] The laser light emitting unit is a semiconductor laser single tube.

[0016] The beneficial effects of the present application are: the semiconductor laser grating external cavity spectrum beam combining device provided by the present application comprises a plurality of laser light emitting units and a first optical path processing unit, a second optical path processing unit and a spectrum beam combining unit, wherein the first optical path processing unit is configured to convert a plurality of beams of laser light corresponding to the output of the plurality of laser light emitting units into a plurality of beams of first collimated light arranged along a first direction, the first direction being perpendicular to the propagation direction of the first collimated light, the second optical path processing unit is configured to convert the plurality of beams of first collimated light into a plurality of beams of second collimated light arranged along a second direction, the propagation direction of the second collimated light being perpendicular to the propagation direction of the first collimated light, and the second direction being perpendicular to the first direction and the propagation direction of the second collimated light, and the spectrum beam combining unit is configured to perform spectrum beam combining on the plurality of beams of second collimated light along the second direction as the spectrum beam combining direction and output, thereby realizing spectrum beam combining with high efficiency and high beam quality, and the beam optical system optical axis and the light source optical axis can be coplanar, making the system structure and adjustment simpler. BRIEF DESCRIPTION OF DRAWINGS

[0017] The technical solutions and other beneficial effects of the present application will become apparent from the following detailed description of the specific embodiments of the present application, combined with the accompanying drawings.

[0018] Fig. 1 is a structural schematic diagram of the semiconductor laser grating external cavity spectrum beam combining device provided by the embodiment of the present application;

[0019] Fig. 2 is a schematic diagram of the arrangement mode of the plurality of beams of first collimated light provided by the embodiment of the present application;

[0020] Fig. 3 is a schematic diagram of the arrangement mode of the plurality of laser light emitting units provided by the embodiment of the present application;

[0021] Fig. 4 is a structural schematic diagram of a rotating mirror provided by the embodiment of the present application. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below in combination with the drawings and embodiments. In particular, the following embodiments are only used to illustrate the present application, but do not limit the scope of the present application. Similarly, the following embodiments are only part of the embodiments of the present application, not all embodiments, and all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] In addition, when describing the structure of a component, when one layer, one region is referred to as being located "on" or "above" another layer, another region, it can mean being directly above the other layer, another region, or other layers or regions are also included between it and the other layer, another region. And if the component is turned over, the layer, the region will be "under" or "below" the other layer, another region. In addition, the features, structures or characteristics described below can be combined in any suitable manner in one or more embodiments.

[0024] The semiconductor laser has the advantages of wide wavelength coverage, high electro-optical conversion efficiency, small volume, good stability, low cost and long service life, and has wide application prospects in many fields such as military industry, industrial processing, medical beauty, scientific research and the like.

[0025] At present, in order to realize the light brightness improvement of the semiconductor laser, the grating external cavity spectrum beam combining structure can be used, but the bar microchannel heat sink structure process is complex, and needs array lens collimation, and the semiconductor laser single tube spacing is large, there are problems of wide beam combining spectrum, limited number of beam combining single tubes and limited power improvement.

[0026] In view of the above problems, the semiconductor laser grating external cavity spectrum beam combining device provided by the embodiment of the present application can convert the multiple beams of laser output corresponding to the multiple laser light emitting units into multiple beams of first collimated light arranged along a first direction by using a first optical path processing unit, the first direction being perpendicular to the propagation direction of the first collimated light, then convert the multiple beams of first collimated light into multiple beams of second collimated light arranged along a second direction by using a second optical path processing unit, the propagation direction of the second collimated light being perpendicular to the propagation direction of the first collimated light, and the second direction being perpendicular to the first direction and the propagation direction of the second collimated light, and then perform spectrum beam combining on the multiple beams of second collimated light by using a spectrum beam combining unit with the second direction as the spectrum beam combining direction and output, so as to realize spectrum beam combining with high efficiency and high beam quality, and the optical axis of the beam combining optical system and the optical axis of the light source can be realized in the same plane, so that the system structure and adjustment are simpler, and thus the spectrum beam combining output with narrow linewidth can be realized in the case of small volume and high stability, which has good application prospect.

[0027] The following will be described in detail in combination with specific embodiments. It should be noted that the sequence numbers of the following embodiments are not limited to the preferred order of the embodiments.

[0028] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a semiconductor laser grating external cavity spectrum beam combining device provided by an embodiment of the present application. As shown in FIG. 1, the semiconductor laser grating external cavity spectrum beam combining device 10 can include a plurality of laser light emitting units 11, and a first light path processing unit 12, a second light path processing unit 13, and a spectrum beam combining unit 14. The first light path processing unit 12 is configured to convert a plurality of laser beams corresponding to the outputs of the plurality of laser light emitting units 11 into a plurality of first collimated lights L1 arranged along a first direction Z, the first direction Z being perpendicular to a propagation direction of the first collimated lights L1 (as shown in FIG. 2). The second light path processing unit 13 is configured to convert the plurality of first collimated lights L1 into a plurality of second collimated lights L2 arranged along a second direction Y, the propagation direction of the second collimated lights L2 being perpendicular to the propagation direction of the first collimated lights L1, and the second direction Y being perpendicular to the first direction Z and the propagation direction of the second collimated lights L2. The spectrum beam combining unit 14 is configured to perform spectrum beam combining on the plurality of second collimated lights L2 along the second direction Y as a spectrum beam combining direction and output.

[0029] In addition, it needs to be noted that, in the embodiment, the laser beams output by the plurality of laser light emitting units 11 are combined to realize power superposition, while the beam quality can be maintained as the high beam quality of a single laser light emitting unit 11, greatly improving the brightness of the semiconductor laser, and the plurality of laser light emitting units 11 can share the beam combining element (i.e., the spectrum beam combining unit 14), so that the structure and adjustment of the beam combining optical system are simpler, and the spatial utilization is improved to realize device miniaturization.

[0030] Specifically, the plurality of first collimated lights L1 arranged along the first direction Z can be located in the same plane, or can be substantially located in the same plane. The plurality of second collimated lights L2 arranged along the second direction Y can be located in the same plane, or can be substantially located in the same plane. In addition, the plane in which the plurality of first collimated lights L1 arranged along the first direction Z is located can be perpendicular to the plane in which the plurality of second collimated lights L2 arranged along the second direction Y is located.

[0031] In the embodiment, as shown in FIG. 1, the propagation direction of the laser beams output by the laser light emitting units 11 can be perpendicular to the first direction Z and the second direction Y, the first direction Z can be a fast axis direction of the laser beams output by the laser light emitting units 11, and the second direction Y can be a slow axis direction of the laser beams output by the laser light emitting units 11. In addition, the plurality of laser beams corresponding to the outputs of the plurality of laser light emitting units 11 can be distributed in parallel, that is, the output optical axes of the laser light emitting units 11 can be parallel to each other.

[0032] Specifically, the laser light emitting unit 11 can be a semiconductor laser single tube, and the output laser light can be linearly polarized light. In some examples, the laser light emitting unit 11 can be a linearly polarized blue light semiconductor laser single tube, and the linearly polarized blue light semiconductor laser single tube can be a linearly polarized blue light semiconductor laser COS chip.

[0033] In the present embodiment, as shown in FIGS. 1 and 3, in a space rectangular coordinate system constructed with a first direction Z and a second direction Y as a Z axis and a Y axis respectively, the projection positions of each laser light emitting unit 11 (such as the laser light emitting unit A1, the laser light emitting unit A2, the laser light emitting unit A3, the laser light emitting unit A4, and the laser light emitting unit A5) on the X axis can all be different, and the projection positions of each laser light emitting unit 11 (such as the laser light emitting unit A1, the laser light emitting unit A2, the laser light emitting unit A3, the laser light emitting unit A4, and the laser light emitting unit A5) on the Z axis can also all be different.

[0034] In some embodiments, as shown in FIG. 3, the plurality of laser light emitting units 11 (such as the laser light emitting unit A1, the laser light emitting unit A2, the laser light emitting unit A3, the laser light emitting unit A4, and the laser light emitting unit A5) can be arranged in sequence along a third direction A, and the angle between the third direction A and a first plane can be an acute angle, and the angle between the third direction A and a second plane can be an acute angle. The first plane is parallel to the first direction Z and the second direction Y, and can be, for example, the plane in which the plurality of first collimated light beams L1 are located. The second plane is parallel to the second direction Y and perpendicular to the first direction Z, and can be, for example, the plane in which the plurality of second collimated light beams L2 are located.

[0035] In some examples, the angle between the third direction A and a third plane can be an acute angle, such as 45 degrees or 60 degrees, and the third plane is perpendicular to the first plane and the second plane.

[0036] In some specific embodiments, the semiconductor laser grating external cavity spectrum beam combining device 10 can further include a base (not shown in the figure), and the plurality of laser light emitting units 11 can be fixed on the base, and the base can cool each laser light emitting unit 11.

[0037] Specifically, the base can be stepped and can have multiple levels of steps. Each laser light emitting unit 11 can be arranged on a level of steps, different laser light emitting units 11 can be arranged on different levels of steps, and the arrangement positions of different laser light emitting units 11 on different levels of steps can be different, that is, different laser light emitting units 11 can be arranged staggered in the height direction of the steps.

[0038] In some embodiments, as shown in FIG. 1, the first light path processing unit 12 can include a plurality of fast-axis collimation mirrors 121, a plurality of slow-axis collimation mirrors 122, and a plurality of reflecting mirrors 123, one fast-axis collimation mirror 121, one slow-axis collimation mirror 122, and one reflecting mirror 123 corresponding to each laser light emitting unit 11, and the laser light output by each laser light emitting unit 11 can be sequentially fast-axis collimated, slow-axis collimated, and reflected by the corresponding fast-axis collimation mirror 121, slow-axis collimation mirror 122, and reflecting mirror 123, and then output as the corresponding first collimated light L1.

[0039] Specifically, as shown in FIG. 1, the fast-axis collimation mirror 121 is configured to fast-axis collimate the laser light output by the corresponding laser light emitting unit 11. In some examples, the fast-axis collimation mirror 121 can be an aspherical cylindrical lens 121, and the focal length of the aspherical cylindrical lens 121 can be 300 microns, for example.

[0040] Specifically, as shown in FIG. 1, the slow-axis collimation mirror 122 is configured to slow-axis collimate the laser light output by the corresponding laser light emitting unit 11. In some examples, the slow-axis collimation mirror 122 can be a cylindrical lens 122, and the focal length of the aspherical cylindrical lens 121 can be 12 mm, for example.

[0041] And for each laser light emitting unit 11, the output face center of the laser light emitting unit 11 and the optical axis of the corresponding fast-axis collimation mirror 121 and slow-axis collimation mirror 122 can be located on the same straight line, and a bundle of laser light output by the laser light emitting unit 11 can be sequentially fast-axis collimated and slow-axis collimated by the corresponding fast-axis collimation mirror 121 and slow-axis collimation mirror 122, and then incident on the corresponding reflecting mirror 123 at a preset angle and reflected by the corresponding reflecting mirror 123 to obtain a bundle of first collimated light L1 (i.e., reflected light) corresponding to the laser light emitting unit 11 and output to the second light path processing unit 13. The preset angle is an acute angle, such as 45 degrees.

[0042] In some embodiments, as shown in FIG. 1, the second light path processing unit 13 can include a half-wave plate 131 and a rotating mirror 132, wherein the half-wave plate 131 can be configured to rotate the polarization direction of each bundle of first collimated light L1 by 90 degrees and then output to the rotating mirror 132, and the rotating mirror 132 can be configured to change the arrangement of each bundle of first collimated light L1 whose polarization direction is rotated by 90 degrees from along the first direction Z to along the second direction Y, that is, the rotating mirror 132 can realize the corresponding change of each bundle of first collimated light L1 along the fast-axis direction Z to each bundle of second collimated light L2 along the slow-axis direction Z.

[0043] It should be noted that, in the embodiment, the polarization direction of each of the plurality of first collimated lights L1 is rotated by 90 degrees by the half-wave plate 131 first, and then the arrangement manner of the plurality of first collimated lights L1 is changed from the arrangement along the first direction Z to the arrangement along the second direction Y by the turning mirror 132, so that the plurality of second collimated lights L2 arranged along the second direction Y is obtained. In this way, the propagation direction and the arrangement manner of each of the plurality of first collimated lights L1 are changed after passing through the half-wave plate 131 and the turning mirror 132, while the polarization direction of each of the plurality of first collimated lights L1 is not changed, that is, the polarization direction of the first collimated light L1 can be the same as the polarization direction of the corresponding second collimated light L2.

[0044] Specifically, as shown in FIG. 1, the half-wave plate 131 and the turning mirror 132 can be located in the transmission direction of the plurality of first collimated lights L1, and the polarization direction of each of the plurality of first collimated lights L1 is rotated by 90 degrees by the half-wave plate 131 after being transmitted through the half-wave plate 131, and each of the plurality of first collimated lights L1 whose polarization direction is rotated by 90 degrees is output from the half-wave plate 131 to the turning mirror 132.

[0045] In some embodiments, as shown in FIG. 4, the turning mirror 132 can include a first reflecting surface adeg and a second reflecting surface bcfg. Each of the plurality of first collimated lights L1 whose polarization direction is rotated by 90 degrees by the half-wave plate 131 is sequentially reflected by the first reflecting surface adeg and the second reflecting surface bcfg, and the output reflected light is the corresponding second collimated light L2. The incident angle of each of the plurality of first collimated lights L1 whose polarization direction is rotated by 90 degrees on the first reflecting surface adeg is an acute angle, and the incident angle of the reflected light of each of the plurality of first collimated lights L1 whose polarization direction is rotated by 90 degrees on the second reflecting surface bcfg after being reflected by the first reflecting surface adeg is also an acute angle.

[0046] Specifically, as shown in FIG. 4, the turning mirror 132 can further include an incident surface abcd and an exit surface cdef, wherein the incident surface abcd is perpendicular to the propagation direction of the first collimated light L1, and the exit surface cdef is perpendicular to the direction of the second collimated light L2. Each of the plurality of first collimated lights L1 whose polarization direction is rotated by 90 degrees by the half-wave plate 131 is incident on the first reflecting surface adeg after passing through the incident surface abcd, and the reflected light from the second reflecting surface bcfg is output as the corresponding second collimated light L2 after passing through the exit surface cdef.

[0047] In some examples, as shown in FIG. 4, the above-mentioned rotating mirror 132 can be a hexahedron structure, and can include an incident surface abcd, an exit surface cdef, a first reflection surface adeg, a second reflection surface bcfg, a first connecting plate efg, and a second connecting surface abg. The incident surface abcd and the exit surface cdef can be right trapezoids, the first reflection surface adeg and the second reflection surface bcfg can be parallelograms, and the first connecting surface efg and the second connecting plate abg can be right triangles. In addition, the bottom side cd of the incident surface abcd can coincide with the bottom side cd of the exit surface cdef, the right leg ad of the incident surface abcd and the oblique leg ed of the exit surface cdef can respectively coincide with two adjacent sides (i.e., the side ad and the side ed) of the first reflection surface adeg, and the remaining two adjacent sides (i.e., the side ag and the side eg) of the first reflection surface adeg can respectively coincide with a right leg eg of the first connecting surface efg and an oblique leg ag of the second connecting plate abg, and the other right leg ef of the first connecting surface efg can coincide with the top side ef of the exit surface cdef. The oblique leg bc of the incident surface abcd and the right leg cf of the exit surface cdef can respectively coincide with two adjacent sides (i.e., the side bc and the side cf) of the second reflection surface bcfg, and the remaining two adjacent sides (i.e., the side bg and the side fg) of the second reflection surface bcfg can respectively coincide with an oblique leg fg of the first connecting surface efg and a right leg bg of the second connecting plate abg, and the other right leg ab of the second connecting plate abg can coincide with the top side ab of the incident surface abcd.

[0048] In the above-mentioned embodiment, as shown in FIG. 1, the optical path experienced by the laser light corresponding to the output of each laser light emitting unit 11 when transmitted to the above-mentioned second optical path processing unit 13 (such as the half-wave plate 131) can be equal, thereby ensuring that the laser light corresponding to the output of each laser light emitting unit 11 can maintain consistent phase difference when transmitted to the above-mentioned second optical path processing unit 13, so as to reduce optical crosstalk caused by the phase difference, and further improve the spectral beam combining efficiency.

[0049] In some examples, as shown in FIG. 1, the above-mentioned spectral beam combining unit 14 can include a lens unit 141, a grating unit 142, and a feedback unit 143. The lens unit 141 can be configured to converge the above-mentioned multiple beams of second collimated light L2 and respectively incident on the grating unit 142 at different angles. The grating unit 142 can be configured to select laser light of a corresponding target wavelength from each beam of second collimated light L2, and each beam of second collimated light L2 can correspond to a different target wavelength. The feedback unit 143 can be configured to return part of the laser light of each target wavelength along the original optical path to the corresponding laser light emitting unit 11, and output the remaining laser light of each target wavelength.

[0050] Specifically, as shown in FIG. 1, the lens unit 141 can be a cylindrical lens, such as a plano-convex cylindrical lens 141, and the front focal plane of the plano-convex cylindrical lens 141 can coincide with or be parallel to the back focal plane of the slow-axis collimating mirror 122.

[0051] Specifically, as shown in FIG. 1, the grating unit 142 can be a plane grating 142, which can be a transmissive plane grating or a reflective plane grating, for example. The grating lines of the plane grating 142 can be parallel to the polarization direction of the second collimated light L2, the center of the plane grating 142 can be located in the back focal plane of the lens unit 141 (such as the plano-convex cylindrical lens 141), and the normal of the plane grating 142 can form a Littrow angle with the optical axis of the lens unit 141 (such as the plano-convex cylindrical lens 141).

[0052] Specifically, the feedback unit 143 can be a partial mirror 143, and the normal of the partial mirror 143 can form a Littrow angle with the normal of the grating unit 142 (such as the plane grating 142), so that the light emitted by the grating unit 142 can be normally incident on the partial mirror 143 and partially reflected by the partial mirror 143 to return along the original path.

[0053] In addition, it should be noted that during the use of the semiconductor laser grating external cavity spectrum beam combining device 10, a resonant cavity can be formed in the semiconductor laser grating external cavity spectrum beam combining device 10, and the resonant cavity can include the plurality of laser light emitting units 11, the first light path processing unit 12, the second light path processing unit 13, and the spectrum beam combining unit 14. In addition, the feedback unit 143 can return part of the light of each target wavelength laser along the original light path to the corresponding laser light emitting unit 11, which can mean that the feedback unit 143 returns part of the light of each target wavelength laser to the corresponding laser light emitting unit 21 in sequence via the grating unit 142, the lens unit 142, the second light path processing unit 13, and the first light path processing unit 12 in the resonant cavity.

[0054] Specifically, the above-mentioned grating unit 142 can have wavelength selectivity, and the incident angles of the lasers output by the laser light emitting units 11 at different positions are different after the lasers are transmitted by the above-mentioned first light path processing unit 12, the above-mentioned second light path processing unit 13 and the above-mentioned lens unit 141 in turn, so that the above-mentioned grating unit 142 can have different wavelength selectivity for the lasers output by the laser light emitting units 11 at different positions, and further, in combination with the feedback of the above-mentioned feedback unit 143, the wavelengths of the lasers output by each laser light emitting unit 11 can be locked at different target wavelengths respectively, so as to realize stable locking and spectral beam combining output of multiple different wavelengths.

[0055] In some embodiments, as shown in FIG. 1, the above-mentioned spectral beam combining unit 14 can further include a filtering unit 144, which can be configured to output the lasers of each target wavelength output by the above-mentioned grating unit 142 (such as a plane grating 142) after increasing the divergence angle respectively to the above-mentioned feedback unit 143 (such as a partial mirror 143), so as to filter out the edge light with a large viewing angle, to reduce the feedback crosstalk of the laser light emitting units 11, and to improve the wavelength locking effect.

[0056] Specifically, as shown in FIG. 1, the above-mentioned filtering unit 144 can include a convex lens 1441 and a concave lens 1442, and the lasers of each target wavelength output by the above-mentioned grating unit 142 can be converged on the concave lens 1442 by the convex lens 1441 respectively, and then output to the above-mentioned feedback unit 143 after being diverged by the concave lens 1442.

[0057] In some embodiments, the above-mentioned semiconductor laser grating external cavity spectral beam combining device 10 can further include an output hole (not shown in the figure), and the remaining light in the lasers of each target wavelength output by the above-mentioned feedback unit 143 can be output by the output hole to realize common-aperture output.

[0058] From the above, the semiconductor laser grating external cavity spectrum beam combining device provided by the embodiment comprises a plurality of laser light emitting units, a first light path processing unit, a second light path processing unit and a spectrum beam combining unit, wherein the first light path processing unit is configured to convert a plurality of beams of laser light corresponding to the output of the plurality of laser light emitting units into a plurality of beams of first collimated light arranged along a first direction, the first direction being perpendicular to the propagation direction of the first collimated light; the second light path processing unit is configured to convert the plurality of beams of first collimated light into a plurality of beams of second collimated light arranged along a second direction, the propagation direction of the second collimated light being perpendicular to the propagation direction of the first collimated light, and the second direction being perpendicular to the first direction and the propagation direction of the second collimated light; and the spectrum beam combining unit is configured to perform spectrum beam combining on the plurality of beams of second collimated light along the second direction as a spectrum beam combining direction and output, so that spectrum beam combining with high efficiency and high beam quality can be realized, and the optical axis of the beam combining optical system and the optical axis of the light source can be coplanar, so that the system structure is simpler to assemble and adjust.

[0059] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A semiconductor laser grating external cavity spectrum beam combining device, characterized in that, The application comprises: a plurality of laser light emitting units; a first light path processing unit configured to convert a plurality of laser beams corresponding to the outputs of the plurality of laser light emitting units into a plurality of first collimated lights arranged along a first direction, the first direction being perpendicular to the propagation direction of the first collimated lights; a second light path processing unit configured to convert the plurality of first collimated lights into a plurality of second collimated lights arranged along a second direction, the propagation direction of the second collimated lights being perpendicular to the propagation direction of the first collimated lights, and the second direction being perpendicular to the first direction and the propagation direction of the second collimated lights; a spectrum beam combining unit configured to perform spectrum beam combining on the plurality of second collimated lights along the second direction as a spectrum beam combining direction and output.

2. The semiconductor laser grating-external cavity combiner of claim 1, wherein, The optical paths of the laser beams corresponding to the outputs of the respective laser light emitting units to the second light path processing unit are equal.

3. The semiconductor laser grating-external cavity combiner of claim 1, wherein, The plurality of laser light emitting units are arranged along a third direction in sequence, the third direction forms an acute angle with a first plane, and the third direction forms an acute angle with a second plane, wherein the first plane is the plane where the plurality of first collimated lights are located, and the second plane is the plane where the plurality of second collimated lights are located.

4. The semiconductor laser grating-external cavity combiner of claim 1, wherein, The second light path processing unit comprises a half-wave plate and a rotating mirror, wherein the half-wave plate is configured to rotate the polarization direction of each of the first collimated lights by 90 degrees and output to the rotating mirror, and the rotating mirror is configured to change the arrangement of each of the first collimated lights with the polarization direction rotated by 90 degrees from along the first direction to along the second direction.

5. The semiconductor laser grating-external cavity combiner of claim 4, wherein, The rotating mirror comprises a first reflecting surface and a second reflecting surface, and each of the first collimated lights with the polarization direction rotated by 90 degrees is reflected by the first reflecting surface and the second reflecting surface in sequence and output as the corresponding second collimated light.

6. The semiconductor laser grating-external cavity beam combination apparatus according to claim 1, wherein, The spectrum beam combining unit comprises a lens unit, a grating unit, and a feedback unit, the lens unit is configured to converge the plurality of second collimated lights and respectively incident on the grating unit at different angles, the grating unit is configured to select laser light of a corresponding target wavelength from each of the second collimated lights and output, each of the second collimated lights corresponds to a different target wavelength, and the feedback unit is configured to return part of the laser light of each target wavelength along the original light path to the corresponding laser light emitting unit and output the remaining laser light of each target wavelength.

7. The semiconductor laser grating-external cavity beam combination apparatus according to claim 6, characterized in that, The spectrum beam combining unit further comprises a filter unit, the filter unit is configured to respectively increase the divergence angle of the laser light of each target wavelength output by the grating unit and output to the feedback unit.

8. The semiconductor laser grating-external cavity beam combination apparatus according to claim 7, characterized in that, The filter unit comprises a convex lens and a concave lens, and the laser light of each target wavelength output by the grating unit is respectively converged on the concave lens through the convex lens and is diverged through the concave lens and output to the feedback unit.

9. The semiconductor laser grating-external cavity beam combination apparatus according to claim 1, characterized in that, The first light path processing unit comprises a plurality of fast-axis collimating mirrors, a plurality of slow-axis collimating mirrors and a plurality of reflecting mirrors, each of the laser light emitting units corresponds to one of the fast-axis collimating mirrors, one of the slow-axis collimating mirrors and one of the reflecting mirrors, and the laser light output by each of the laser light emitting units is sequentially subjected to fast-axis collimation, slow-axis collimation and reflection by the corresponding fast-axis collimating mirror, slow-axis collimating mirror and reflecting mirror, and is output as corresponding first collimated light.

10. The semiconductor laser grating-external cavity beam combination apparatus according to claim 1, characterized in that, The laser light emitting unit is a semiconductor laser single tube.

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