Dual-grating external cavity light spectrum beam combining device

Abstract

The application relates to a double-grating external cavity spectrum beam combining device, which comprises, in sequence, a semiconductor laser array light source, a fast-axis collimating mirror, a slow-axis collimating mirror, an optical path compensation device, a pair of diffraction gratings, a collimating lens and an output coupling mirror. The optical path compensation device comprises a plurality of optical path compensation components, and each of the optical path compensation components corresponds to each sub-beam in the array beam. In the independent light path transmission paths of each sub-beam of the array beam, one optical path compensation component is installed respectively, the external cavity length of each sub-beam and the beam combining efficiency are changed through the optical path compensation components, specifically, through the design that the reflection component mounting platform drives the reflection component to move upward, the optical path of the sub-beam can be increased, the external cavity length is increased, the beam combining efficiency is improved, the stability and the precision of the system can be improved at the same time. The last cylindrical lens can compensate for the optical error introduced in the light beam transmission process, so that each sub-beam has good wavefront uniformity and phase consistency.

Description

Technical Field

[0001] The present application relates to the field of laser beam combining technology, and in particular to a dual-grating external cavity spectral beam combining device. Background Art

[0002] High-power semiconductor lasers have the characteristics of lightweight, maintenance-free and high reliability, and have broad application prospects in the fields of intelligent equipment manufacturing, medical treatment and communications. The double-grating spectrum combining structure is a spectrum combining technology widely used in high-power semiconductor lasers. This structure can suppress feedback crosstalk between adjacent sub-units and avoid beam quality degradation through dispersion compensation, thereby achieving narrow linewidth output. However, since this structure uses two gratings, the beam combining efficiency after the light beam passes through the grating external cavity is lost compared to the traditional spectrum combining structure. Beam combining efficiency is an important indicator for evaluating the quality of the external cavity semiconductor laser spectrum combining system, and the optical path (external cavity length) of the light beam propagating in the grating external cavity will affect the beam combining efficiency. Therefore, when the optical elements used in the structure are determined, adjusting the external cavity length is the key to solving the loss of beam combining efficiency.

[0003] Currently, the main methods for adjusting the external cavity length are: (1) increasing the external cavity length by adjusting the inherent optical elements in the structure, but this can easily disrupt optical alignment, introduce additional stray light and energy loss, and lead to reduced efficiency and beam quality. (2) adding an acousto-optic modulator, but this will introduce higher losses and reduce system stability. (3) adding liquid crystal optical devices. Although liquid crystal optical devices have dynamic adjustment and high precision characteristics, they have problems such as high energy loss, a small optical path adjustment range, and high cost. Summary of the Invention

[0004] In order to at least to some extent overcome the problems of high energy loss and poor system stability in the dual-grating spectral beam combining structure in the related art when adjusting the external cavity length, the present application provides a dual-grating external cavity spectral beam combining device.

[0005] The scheme of this application is as follows:

[0006] A dual-grating external cavity spectral beam combining device, comprising:

[0007] A semiconductor laser array light source, a fast axis collimator, a slow axis collimator, an optical path compensation device, a diffraction grating pair, a collimator lens and an output coupling mirror are arranged in sequence;

[0008] The semiconductor laser array light source is used to emit an array beam, so that the array beam passes through the rear fast axis collimator, the slow axis collimator, the optical path compensation device, the diffraction grating pair, the collimator lens and the output coupling mirror in sequence;

[0009] Wherein, the optical path compensation device comprises: a plurality of optical path compensation components, each of which corresponds to each sub-beam in the array beam;

[0010] The optical path compensation assembly includes: a reflection assembly, a reflection assembly mounting platform, a right-angle reflection prism, a prism bracket, a cylindrical lens and a cylindrical lens bracket;

[0011] The reflective component mounting platform includes two relatively vertical mounting surfaces;

[0012] The reflective assembly includes a first reflective assembly and a second reflective assembly, and the first reflective assembly and the second reflective assembly are respectively arranged on two mounting surfaces of the reflective assembly mounting platform;

[0013] The right-angle reflecting prism includes a bottom surface, and a first reflecting surface and a second reflecting surface that are relatively perpendicular to each other;

[0014] The first reflective component is parallel to and opposite to the first reflective surface of the right-angle reflective prism, and the second reflective component is parallel to and opposite to the second reflective surface of the right-angle reflective prism;

[0015] Based on the light beam transmission path, the cylindrical lens is arranged at a rear position of the reflection component and the right-angle reflection prism;

[0016] The sub-beams of the array light beam are refracted in sequence by the first reflection surface of the right-angle reflection prism, the first reflection component, the second reflection component and the second reflection surface of the right-angle reflection prism, and then transmitted to the cylindrical lens;

[0017] The prism bracket supports the right-angle reflection prism;

[0018] The cylindrical lens support supports the cylindrical lens;

[0019] The reflective component mounting platform drives the reflective component to move up and down through a transmission mechanism to perform optical path compensation on the sub-beams in the array beam.

[0020] Preferably, the cylindrical lens holder drives the cylindrical lens to move left and right through a transmission mechanism, so as to collimate the array light beam after optical path compensation.

[0021] Preferably, the first reflective component is arranged at an angle of 135° relative to the incident direction of the array light beam;

[0022] The second reflective component is arranged at an angle of 45° relative to the incident direction of the array light beam.

[0023] Preferably, the fast-axis collimator and the slow-axis collimator are arranged perpendicularly to the incident direction of the array light beam;

[0024] The fast-axis collimator and the slow-axis collimator are used to collimate the incident array light beam.

[0025] Preferably, the diffraction grating pair is tilted relative to the incident direction of the array light beam;

[0026] The diffraction grating pair is used to combine the array light beams after optical path compensation.

[0027] Preferably, the collimating lens and the output coupling mirror are arranged perpendicularly to the incident direction of the combined light beam output by the diffraction grating;

[0028] The collimating lens is used to collimate the combined light beam;

[0029] The output coupling mirror is used to couple the collimated combined light beam to output.

[0030] Preferably, it further comprises: a collimating lens bracket;

[0031] The collimating lens bracket is used to support the collimating lens.

[0032] Preferably, the rear cavity surface of the semiconductor laser array light source and the output coupling mirror form a laser resonant external cavity.

[0033] Preferably, the first reflective component, the second reflective component, the first reflective surface of the right-angle reflective prism, and the second reflective surface of the right-angle reflective prism are all coated with a reflective film layer.

[0034] The technical solution provided by this application may have the following beneficial effects:

[0035] The double-grating external cavity spectral beam combining device in the present application comprises: a semiconductor laser array light source, a fast-axis collimator, a slow-axis collimator, an optical path compensation device, a diffraction grating pair, a collimating lens and an output coupling mirror arranged in sequence; the semiconductor laser array light source is used to emit an array light beam, so that the array light beam passes through the rear fast-axis collimator, the slow-axis collimator, the optical path compensation device, the diffraction grating pair, the collimating lens and the output coupling mirror in sequence; wherein the optical path compensation device comprises: a plurality of optical path compensation components, the optical path compensation components corresponding to each sub-beam in the array light beam one by one; the optical path compensation component comprises: a reflection component, a reflection component mounting platform, a right-angle reflection prism, a prism bracket, a cylindrical lens and a cylindrical lens bracket; the reflection component mounting platform comprises two relatively vertical mounting surfaces; the reflection component comprises a first reflection component and a second reflection component, the first reflection component and the second reflection component The components are respectively arranged on two mounting surfaces of the reflective component mounting platform; the right-angle reflective prism includes a bottom surface, and a first reflective surface and a second reflective surface that are relatively perpendicular to each other; the first reflective component is parallel to and opposite to the first reflective surface of the right-angle reflective prism, and the second reflective component is parallel to and opposite to the second reflective surface of the right-angle reflective prism; based on the light beam transmission path, the cylindrical lens is arranged at a rear position of the reflective component and the right-angle reflective prism; the sub-beams of the array light beam are refracted in sequence by the first reflective surface of the right-angle reflective prism, the first reflective component, the second reflective component and the second reflective surface of the right-angle reflective prism, and then transmitted to the cylindrical lens; the prism bracket supports the right-angle reflective prism; the cylindrical lens bracket supports the cylindrical lens; the reflective component mounting platform drives the reflective component to move up and down through a transmission mechanism to perform optical path compensation on the sub-beams in the array light beam.

[0036] In this technical solution, an optical path compensation component is installed in each independent optical path transmission path of each sub-beam of the array light beam. The optical path compensation component is used to change the external cavity length and beam combining efficiency of each sub-beam. Specifically, the design of driving the reflective component upward by the reflective component mounting platform can increase the optical path of the sub-beam, thereby increasing the external cavity length and improving the beam combining efficiency. At the same time, the reflective component and the right-angle reflective prism adopt the principle of mirror reflection to efficiently reflect the light beam and reduce the loss of light intensity. In addition, the relative arrangement of the reflective component and the right-angle reflective prism can ensure that the light beam reflected by the second reflective surface of the right-angle reflective prism is still transmitted along the predetermined optical path, which can improve the stability and accuracy of the system. Finally, the design of introducing a cylindrical lens in the optical path compensation component can compensate for the optical error introduced during the light beam transmission process, thereby ensuring that each sub-beam has good wavefront uniformity and phase consistency.

[0037] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0039] Figure 1 This is a schematic structural diagram of a dual-grating external cavity spectral beam combining device provided by one embodiment of the present application;

[0040] Figure 2 This is a schematic diagram of an optical path compensation component in a dual-grating external cavity spectral beam combining device provided by one embodiment of the present application;

[0041] Figure 3 This is a schematic diagram of the optical path of an array light beam passing through an optical path compensation device provided by one embodiment of the present application;

[0042] Figure 4 This is a schematic diagram showing that the beam combining efficiency varies periodically with the increase of the external cavity length, provided in one embodiment of the present application.

[0043] Figure numerals: semiconductor laser array light source-1; fast axis collimator-2; slow axis collimator-3; optical path compensation device-4; reflection assembly-403; reflection assembly mounting platform-404; right-angle reflection prism-405; first reflection surface of right-angle reflection prism-405(1); second reflection surface of right-angle reflection prism-405(2); prism holder-406; cylindrical lens-407; cylindrical lens holder-408; diffraction grating pair-5; collimator lens-6; output coupling mirror-7; collimator lens holder-8. DETAILED DESCRIPTION

[0044] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0045] Figure 1 This is a schematic diagram of the structure of a dual-grating external cavity spectral beam combining device provided by an embodiment of the present application, referring to Figure 1 , a dual-grating external cavity spectral beam combining device, comprising:

[0046] A semiconductor laser array light source 1, a fast axis collimator 2, a slow axis collimator 3, an optical path compensation device 4, a diffraction grating pair 5, a collimator lens 6 and an output coupling mirror 7 are arranged in sequence;

[0047] The semiconductor laser array light source 1 is used to emit an array beam, so that the array beam passes through the rear fast axis collimator 2, the slow axis collimator 3, the optical path compensation device 4, the diffraction grating pair 5, the collimator lens 6 and the output coupling mirror 7 in sequence;

[0048] Among them, reference Figure 2 The optical path compensation device 4 includes: a plurality of optical path compensation components, each of which corresponds to each sub-beam in the array beam;

[0049] The optical path compensation assembly includes: a reflection assembly 403, a reflection assembly mounting platform 404, a right-angle reflection prism 405, a prism bracket 406, a cylindrical lens 407 and a cylindrical lens bracket 408;

[0050] The reflective assembly mounting platform 404 includes two relatively vertical mounting surfaces;

[0051] The reflective assembly 403 includes a first reflective assembly and a second reflective assembly, which are respectively arranged on two mounting surfaces of the reflective assembly mounting platform 404;

[0052] The right-angle reflecting prism 405 includes a bottom surface, and a first reflecting surface and a second reflecting surface that are relatively perpendicular to each other;

[0053] The first reflective component is parallel to and opposite to the first reflective surface 405(1) of the right-angle reflective prism, and the second reflective component is parallel to and opposite to the second reflective surface 405(2) of the right-angle reflective prism;

[0054] Based on the light beam transmission path, the cylindrical lens 407 is arranged at a rear position of the reflection component 403 and the right-angle reflection prism 405;

[0055] The sub-beams of the array light beam are refracted in sequence by the first reflection surface 405 (1) of the right-angle reflection prism, the first reflection component, the second reflection component and the second reflection surface 405 (2) of the right-angle reflection prism, and then transmitted to the cylindrical lens 407;

[0056] The prism support 406 supports the right-angle reflecting prism 405;

[0057] The cylindrical lens holder 408 supports the cylindrical lens 407;

[0058] The reflective component mounting platform 404 drives the reflective component 403 to move up and down through a transmission mechanism to perform optical path compensation on the sub-beams in the array beam.

[0059] like Figure 1As shown, the optical components are arranged in the order of the beam transmission path, namely, a semiconductor laser array light source 1, a fast-axis collimator 2, a slow-axis collimator 3, an optical path compensation device 4, a diffraction grating pair 5, a collimating lens 6, and an output coupling mirror 7. Among them, the semiconductor laser array light source 1, the fast-axis collimator 2, the slow-axis collimator 3, the diffraction grating pair 5, the collimating lens 6, and the output coupling mirror 7 are conventional optical components in the prior art and are not described in detail here.

[0060] Figure 3 Schematic diagram of the optical path of the array beam passing through the optical path compensation device 4, as shown Figure 3 As shown, an optical path compensation component is installed in each independent optical transmission path of each sub-beam to accurately adjust the transmission path of each beam and improve beam combining efficiency. The semiconductor laser array light source 1 includes multiple light-emitting sub-units, each of which is arranged at equal intervals. 100, 101, and 102 are the central sub-unit and the end sub-units on both sides of the semiconductor laser array, respectively. 400, 401, and 402 are the beams emitted by sub-units 100, 101, and 102, respectively.

[0061] Taking the light beam transmission of light beam 400 as an example, light beam 400 is collimated by fast axis collimator 2 and slow axis collimator 3 and then vertically incident on the first reflection surface 405 (1) of the right-angle reflection prism. The first reflection surface 405 (1) of the right-angle reflection prism reflects the vertically incident light beam to the first reflection component, which is then reflected by the first reflection component to the second reflection component, and then reflected by the second reflection component to the second reflection surface 405 (2) of the right-angle reflection prism. It is reflected and output by the second reflection surface 405 (2) of the right-angle reflection prism, and finally output after being collimated and compensated by cylindrical lens 407.

[0062] It should be noted that the length of the external cavity after each sub-beam in the semiconductor laser array light source 1 passes through the grating external cavity is L EC and the beam combining efficiency η m Determined by the following formula:

[0063]

[0064] Assuming that the laser energy emitted by each sub-beam of the semiconductor laser array is the same, the beam combining efficiency of the 2m+1 beam after passing through the grating external cavity is:

[0065]

[0066] Where f is the distance from the semiconductor laser array light source 1 to the first central subunit, m·Δp is the distance between the mth subunit and the central subunit, α0 represents the incident angle of the central subunit with a wavelength of λ0, h1 is the grating spacing, and z is the transmission distance. m is the external cavity feedback strength parameter, ω m =2πc / λm is the oscillation frequency of the mth subunit in the semiconductor laser array light source 1 in the external cavity, τ EC =2L EC / c is the round trip time of photons in the external cavity, G N is the differential gain coefficient, τ IC =2nL IC / c is the round trip time of photons in the cavity, R = J / (eV) is the carrier injection rate per unit volume, τ c is the carrier lifetime, N T =N0+1 / (G N τ p ) is the threshold carrier density, R3 is the external cavity equivalent reflectivity, τ c is the photon lifetime.

[0067] When the incident angle is the Littrow angle, according to the grating equation, the incident angle of the central subunit with a wavelength of λ0 can be expressed as:

[0068]

[0069] Where λ0 is the wavelength of the central subunit and d is the grating period.

[0070] It can be seen from the above formula that adjusting the length of the external cavity is the key to solving the loss of beam combining efficiency.

[0071] In this embodiment, a semiconductor laser array light source 1 is used to emit an array light beam, so that the array light beam passes through a rear fast-axis collimator 2, a slow-axis collimator 3, an optical path compensation device 4, a diffraction grating pair 5, a collimator lens 6 and an output coupling mirror 7 in sequence, and the rear cavity surface of the semiconductor laser array light source 1 and the output coupling mirror 7 form a laser resonant external cavity.

[0072] In this technical solution, the reflective component 403 is installed on the reflective component installation platform 404, and the reflective component installation platform 404 drives the reflective component 403 to move up and down through the transmission mechanism, and realizes the optical path folding and optical path compensation by changing the transmission direction of the sub-beam.

[0073] Preferably, the reflective assembly 403 is moved minutely in segments, increasing the optical path length of each sub-beam by 50 nm at a time. The combining efficiency is recorded for each 50 nm increase in optical path length, and the changing trend of the combining efficiency is observed until the combining efficiency of the beam reaches a peak. The total optical path length increase at this point is recorded, and the total external cavity length at which the combining efficiency reaches the peak is calculated. Finally, the total combining efficiency after the external cavity length adjustment is calculated using a formula.

[0074] In practice, the following records should be kept when adjusting the optical path compensation device 4: First, adjust the reflector assembly mounting platform 404 to its initial position and reset it, and calculate the external cavity length and beam combining efficiency of each sub-beam transmitted in the external cavity at this time; secondly, Figure 3 Move the reflective assembly mounting platform 404 in the direction of the arrow shown in the figure and adjust the cylindrical lens 407 appropriately. Record the beam combining efficiency when the optical path of each sub-beam increases by 50nm. Observe the changing trend of the beam combining efficiency until the beam combining efficiency reaches the peak value. Record the total optical path ΔL increased at this time. EC And calculate the external cavity length (L EC +ΔL EC ), where L EC is the initial external cavity length. Finally, the total beam combining efficiency after the external cavity length is adjusted is calculated using the formula.

[0075] Reference Figure 4 , the semiconductor laser array light source 1 includes 21 light-emitting units.

[0076] like Figure 4 As shown in the figure, the calculated bundle combining efficiency of the terminal subunit and the central subunit varies with the length of the external cavity; Figure 4 The upper graph shows the variation of the beam combining efficiency of the -10th subunit with the length of the external cavity; Figure 4 The middle graph shows the variation of the beam combining efficiency of the central subunit with the length of the external cavity; Figure 4 The figure below shows the variation of the beam combining efficiency of the 10th subunit with the length of the external cavity. EC is the length of the external cavity during the transmission of the light beam, η m is the beam combining efficiency of the mth subunit. The hollow points indicate the beam combining efficiency before adding the optical path compensator 4, and the solid points indicate the peak beam combining efficiency achieved after increasing the external cavity length. Before adding the optical path compensator 4, the beam combining efficiencies of the -10th subunit, the center subunit, and the 10th subunit were 67.29%, 69.12%, and 71.36%, respectively. After adding the optical path compensator 4 and increasing the external cavity length, all subunits reached their peak beam combining efficiency of 72.56%.

[0077] like Figure 4 As shown, the beam combining efficiency changes periodically with the increase of the external cavity length. The maximum beam combining efficiency of each sub-unit is 72.56%, and the minimum is 66.57%. The beam combining efficiency of 21 beams after passing through the grating external cavity is 69.13%. When the optical path compensation device 4 is added, the external cavity length of each sub-beam is increased. At this time, the beam combining efficiency of 21 beams after passing through the grating external cavity is increased to 72.56%.

[0078] The above practice proves that the technical scheme increases the propagation optical path of each sub-beam in the grating external cavity through the optical path compensation device 4, improves the beam combining efficiency of each sub-beam, thereby improving the total beam combining efficiency, and provides an effective way to solve the efficiency loss in double-grating spectrum beam combining.

[0079] In an implementable manner of the embodiment, the cylindrical lens support 408 drives the cylindrical lens 407 to move left and right through a transmission mechanism to collimate the array beam after optical path compensation.

[0080] Preferably, the cylindrical lens support 408 also drives the cylindrical lens 407 to move left and right in the embodiment, which is used to collimate each sub-beam to ensure good wavefront uniformity and phase consistency.

[0081] Preferably, the first reflection component is arranged at an angle of 135° with respect to the incident direction of the array beam.

[0082] The second reflection component is arranged at an angle of 45° with respect to the incident direction of the array beam.

[0083] The first reflection component, the second reflection component, the first reflection surface 405(1) of the right-angle reflection prism, and the second reflection surface 405(2) of the right-angle reflection prism are all coated with a reflection film layer.

[0084] The first reflection component is arranged at an angle of 135° with respect to the incident direction of the array beam, so that the first reflection surface 405(1) of the right-angle reflection prism is also arranged at an angle of 135° with respect to the incident direction of the array beam; the second reflection component is arranged at an angle of 45° with respect to the incident direction of the array beam, so that the second reflection surface 405(2) of the right-angle reflection prism is also arranged at an angle of 45° with respect to the incident direction of the array beam.

[0085] It should be noted that the first reflection component, the second reflection component, the first reflection surface 405(1) of the right-angle reflection prism, and the second reflection surface 405(2) of the right-angle reflection prism are all coated with a reflection film layer with high reflectivity, so that the single-surface reflectivity can be greater than 99% when the angle of incidence is 45°.

[0086] In specific practice, the fast-axis collimating mirror 2 and the slow-axis collimating mirror 3 are arranged perpendicularly with respect to the incident direction of the array beam.

[0087] The fast-axis collimating mirror 2 and the slow-axis collimating mirror 3 are used to collimate the incident array beam.

[0088] The fast-axis collimator 2 and the slow-axis collimator 3 are arranged perpendicularly to the incident direction of the array light beam, that is, the fast-axis collimator 2 and the slow-axis collimator 3 are parallel to each other. The fast-axis collimator 2 and the slow-axis collimator 3 are used to collimate the array light beam emitted by the semiconductor laser array light source 1 in the fast-axis and slow-axis directions, respectively, and then the collimated light beam is incident on the first reflecting surface 405(1) of the right-angle reflecting prism.

[0089] It should be noted that, referring to Figure 1 , the diffraction grating pair 5 is tilted relative to the incident direction of the array beam;

[0090] The diffraction grating pair 5 is used to combine the array light beams after optical path compensation.

[0091] The diffraction grating pair 5 is tilted relative to the incident direction of the array beam in order to combine the array beam after optical path compensation. The diffraction grating pair 5 includes two parallel diffraction gratings. Figure 1 The diffraction grating on the left side is used to combine the array light beams output from the second reflection surface 405 (2) of the right-angle reflection prism. Figure 1 The diffraction grating on the middle right is used to output the combined light beam.

[0092] It should be noted that the collimating lens 6 and the output coupling mirror 7 are arranged perpendicularly to the incident direction of the combined light beam output by the diffraction grating;

[0093] The collimating lens 6 is used to collimate the combined light beam;

[0094] The output coupling mirror 7 is used to couple the collimated combined light beam to output.

[0095] The collimating lens 6 and the output coupling mirror 7 are arranged perpendicularly to the incident direction of the combined light beam output by the diffraction grating, and the collimating lens 6 and the output coupling mirror 7 are parallel to each other.

[0096] The collimating lens 6 is used to collimate the combined light beam, reduce the divergence angle of the combined light beam, and keep a small divergence angle during the propagation process, thereby maintaining the parallelism and coherence of the light beam over a long distance.

[0097] Further, such as Figure 1 As shown, the dual-grating external cavity spectral beam combining device further includes: a collimating lens bracket 8;

[0098] The collimating lens holder 8 is used to support the collimating lens 6 .

[0099] In this embodiment, the collimating lens 6 is fixed by the collimating lens holder 8 , and the collimating lens 6 does not need to be moved.

[0100] In summary, in this technical solution, an optical path compensation component is installed in each independent optical path transmission path of each sub-beam of the array light beam, and the external cavity length and beam combining efficiency of each sub-beam are changed by the optical path compensation component. Specifically, the design of driving the reflective component 403 to move upward by the reflective component mounting platform 404 can increase the optical path of the sub-beam, thereby increasing the external cavity length and improving the beam combining efficiency. At the same time, the reflective component 403 and the right-angle reflective prism 405 adopt the principle of mirror reflection to efficiently reflect the light beam and reduce the loss of light intensity. In addition, the relative arrangement of the reflective component 403 and the right-angle reflective prism 405 can ensure that the light beam reflected by the second reflective surface 405 (2) of the right-angle reflective prism is still transmitted along the predetermined optical path, which can improve the stability and accuracy of the system. Finally, the design of introducing the cylindrical lens 407 in the optical path compensation component can compensate for the optical error introduced during the light beam transmission process, thereby ensuring that each sub-beam has good wavefront uniformity and phase consistency.

[0101] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0102] It should be noted that, in the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0103] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0104] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A dual-grating external cavity spectral beam combining device, characterized in that: include: A semiconductor laser array light source, a fast axis collimator, a slow axis collimator, an optical path compensation device, a diffraction grating pair, a collimator lens and an output coupling mirror are arranged in sequence; The semiconductor laser array light source is used to emit an array beam, so that the array beam passes through the rear fast axis collimator, the slow axis collimator, the optical path compensation device, the diffraction grating pair, the collimator lens and the output coupling mirror in sequence; Wherein, the optical path compensation device comprises: a plurality of optical path compensation components, each of which corresponds to each sub-beam in the array beam; The optical path compensation assembly includes: a reflection assembly, a reflection assembly mounting platform, a right-angle reflection prism, a prism bracket, a cylindrical lens and a cylindrical lens bracket; The reflective component mounting platform includes two relatively vertical mounting surfaces; The reflective assembly includes a first reflective assembly and a second reflective assembly, and the first reflective assembly and the second reflective assembly are respectively arranged on two mounting surfaces of the reflective assembly mounting platform; The right-angle reflecting prism includes a bottom surface, and a first reflecting surface and a second reflecting surface that are relatively perpendicular to each other; The first reflective component is parallel to and opposite to the first reflective surface of the right-angle reflective prism, and the second reflective component is parallel to and opposite to the second reflective surface of the right-angle reflective prism; Based on the light beam transmission path, the cylindrical lens is arranged at a rear position of the reflection component and the right-angle reflection prism; The sub-beams of the array light beam are refracted in sequence by the first reflection surface of the right-angle reflection prism, the first reflection component, the second reflection component and the second reflection surface of the right-angle reflection prism, and then transmitted to the cylindrical lens; The prism bracket supports the right-angle reflection prism; The cylindrical lens support supports the cylindrical lens; The reflective component mounting platform drives the reflective component to move up and down through a transmission mechanism to perform optical path compensation on the sub-beams in the array beam.

2. The dual-grating external cavity spectral beam combining device according to claim 1, characterized in that: The cylindrical lens holder drives the cylindrical lens to move left and right through a transmission mechanism to collimate the array light beam after optical path compensation.

3. The dual-grating external cavity spectral beam combining device according to claim 1, characterized in that: The first reflective component is arranged at an angle of 135° relative to the incident direction of the array light beam; The second reflective component is arranged at an angle of 45° relative to the incident direction of the array light beam.

4. The dual-grating external cavity spectral beam combining device according to claim 3, characterized in that: The fast-axis collimator and the slow-axis collimator are arranged perpendicularly to the incident direction of the array light beam; The fast-axis collimator and the slow-axis collimator are used to collimate the incident array light beam.

5. The dual-grating external cavity spectral beam combining device according to claim 4, characterized in that: The diffraction grating pair is tilted relative to the incident direction of the array light beam; The diffraction grating pair is used to combine the array light beams after optical path compensation.

6. The dual-grating external cavity spectral beam combining device according to claim 5, characterized in that: The collimating lens and the output coupling mirror are arranged perpendicularly to the incident direction of the combined light beam output by the diffraction grating; The collimating lens is used to collimate the combined light beam; The output coupling mirror is used to couple the collimated combined light beam to output.

7. The dual-grating external cavity spectral beam combining device according to claim 1, characterized in that: Also includes: Collimating lens holder; The collimating lens bracket is used to support the collimating lens.

8. The dual-grating external cavity spectral beam combining device according to claim 1, characterized in that: The rear cavity surface of the semiconductor laser array light source and the output coupling mirror form a laser resonant external cavity.

9. The dual-grating external cavity spectral beam combining device according to claim 1, characterized in that: The first reflective component, the second reflective component, the first reflective surface of the right-angle reflective prism and the second reflective surface of the right-angle reflective prism are all coated with a reflective film layer.

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