CN117913664A - Aplanatic semiconductor laser beam combining structure and multi-single-tube spectrum beam combining structure - Google Patents

Abstract

The embodiment of the disclosure provides an aplanatic semiconductor laser beam combining structure and a multi-single-tube spectrum beam combining structure, the aplanatic semiconductor laser beam combining structure comprises: at least one laser chip (10) is symmetrically arranged relative to the optical fiber (40) according to a preset angle, and light spots of the laser chip are arranged along the fast axis direction and are equal to the optical path between the optical fibers (40); the fast axis focusing mirror (20) and the slow axis focusing mirror (30) are sequentially arranged on the optical path between the laser chip (10) and the optical fiber (40) and are used for focusing laser in the fast axis and slow axis directions; and the optical fiber (40) is arranged on the symmetry axis of at least one laser chip (10) and is used for receiving the focused laser beam. The optical path semiconductor laser beam combining structure can balance the light spot size and the light beam quality of the output laser in two directions, and is easier to carry out light beam shaping and coupling into an optical fiber (40). The multi-single-tube spectrum beam combining structure is similar to the beam combining structure of the aplanatic semiconductor laser beam combining structure, and the same technical effect can be achieved.

Description

Aplanatic semiconductor laser beam combining structure and multi-single-tube spectrum beam combining structure

Technical Field

The disclosure relates to the technical field of semiconductor lasers, in particular to an aplanatic semiconductor laser beam combining structure and a multi-single-tube spectrum beam combining structure.

Background

The semiconductor laser has the advantages of small volume, light weight, high conversion efficiency, long service life, direct modulation, easy integration with other semiconductor devices and the like, and is widely used in the fields of solid and fiber laser pumping, laser processing, laser radar, laser weapon, microsatellite, laser guidance and the like. The light output power of a single semiconductor laser chip is limited, and the output power of the optical fiber can be improved by tens of times compared with that of the single semiconductor laser chip through a beam combination technology. The laser beam combining is a process of coupling a plurality of laser beams into one beam, and based on the characteristics of the semiconductor laser such as phase, light intensity, polarization, spectrum and the like, the oscillation characteristics of the laser units are changed or not changed by utilizing the refraction, reflection and diffraction effects of the optical elements so as to improve the output power, the laser brightness and the beam quality.

The laser beam is mainly divided into coherent and incoherent beams. The coherent beam combination can also be called array phase locking, each beam combination unit of the semiconductor laser is required to have the same laser spectrum, and the phase relation among the laser units is required to be strictly controlled to ensure that a beneficial interference can be generated, so that the requirements of the coherent beam combination technology on the stability of the environment temperature and the precision of an instrument are extremely high, the realization process is complex, and the high-power stable output of the in-phase supermode is not easy to obtain. The incoherent beam combines multiple incoherent lights in near field or far field, does not need to strictly control phase, spectrum and frequency, is easier to debug and is relatively easy to realize, and mainly comprises spatial beam combination, polarization beam combination, wavelength beam combination and spectrum beam combination. The space beam combination means that a plurality of semiconductor laser single tubes are linearly arranged in space according to a certain filling factor, the filling factor is improved by a plurality of methods, so that the arrangement between light beams is tighter, the power is improved, but the quality of the light beams is slightly deteriorated; the polarization beam combination means that two beams of light with mutually perpendicular polarization states are overlapped in a near field and a far field by utilizing a polarization spectroscope, so that the overall power density is doubled under the condition of keeping the quality of the light beams unchanged, and the output brightness of laser is further improved; the wavelength beam combination means that two or more laser beams with different wavelengths are combined in the same path through a wavelength beam combination device, and the output power is doubled under the condition that the quality of the laser beams is kept unchanged, so that the brightness of the output laser beams is greatly increased; the spectrum beam combination refers to adding external cavity feedback based on wavelength beam combination, taking narrow beam combination wavelength interval as a target, utilizing an interference filter or a dispersion element to enable each unit beam to overlap in a near field or a far field, and realizing the effect that the output laser can increase power and simultaneously keep the beam quality equivalent to that of a single light-emitting unit.

In a conventional optical fiber coupling module, a plurality of laser chips with a certain step height difference along a fast axis direction are arranged side by side along a slow axis direction, fast and slow axis light beams are firstly collimated, then light spots are rearranged through a plurality of reflectors to obtain a light spot pattern which is arranged along the fast axis direction, and then the fast and slow axis light beams are respectively or simultaneously coupled into an optical fiber through a focusing lens. The method needs to strictly design the step height difference on the heat sink, has extremely high requirements on the processing precision of the heat sink and the directivity of the fast axis light beam, is extremely easy to cause the loss of the light beam energy when passing through the reflecting mirror, and has the advantages of multiple optical elements, complex adjustment steps and larger power loss.

In a conventional beam combining structure of a bar spectrum, a laser bar is mostly adopted as a beam combining light source, the system is large in size and high in assembly and adjustment difficulty, and a "smile" effect is inevitably generated by the bar due to the existence of packaging thermal stress, so that a certain difficulty is brought to the subsequent external cavity locking. When the laser bar is used for beam collimation and shaping, the requirement on the adjustment precision of a collimating mirror or an array mirror is high; because of the characteristics of the beam combination structure, the distance from the bar to the transmission lens is equal to the distance from the transmission lens to the grating and is equal to the focal length of the transmission lens, so that the system volume is difficult to further reduce; the packaging difficulty of the bar is high, a smile effect is inevitably generated due to the existence of thermal stress, and great difficulty is brought to the subsequent external cavity locking; when the bar is used for beam collimation and shaping, the requirement on the adjustment precision of a collimating mirror or an array mirror is high; the bar power is larger, the requirement on heat dissipation is high, and the performance of the laser chip is easy to degrade.

Disclosure of Invention

In view of the above problems, the present invention provides an aplanatic semiconductor laser beam combining structure and a multi-single-tube spectrum beam combining structure to solve the above technical problems.

One aspect of the present disclosure provides an aplanatic semiconductor laser beam combining structure comprising: at least one laser chip is symmetrically arranged relative to the optical fiber according to a preset angle, so that light spots of the laser chips are arranged along the fast axis direction, and optical paths between the laser chips and the optical fiber are equal; the fast axis focusing mirror and the slow axis focusing mirror are sequentially arranged on the light path between the laser chip and the optical fiber and are respectively used for focusing the laser beam generated by the laser chip in the fast axis direction and the slow axis direction; and the optical fiber is arranged on the symmetry axis of the at least one laser chip, and the end face of one end is used for receiving the focused laser beams, wherein when the number of the laser chips is greater than 1, the end face is arranged at the intersection point of the optical paths of the laser chips.

Optionally, the method further comprises: a heat sink, the surface of which is a plane; the at least one laser chip is arranged on the heat sink.

Optionally, the heat sink further comprises: the laser chip fixing blocks are arranged at positions corresponding to the laser chips and used for fixing the laser chips.

Optionally, the heat sink further comprises: and the surface of the optical fiber fixing block is provided with a groove for fixing the optical fiber.

Optionally, the light-emitting surface of the laser chip is plated with an antireflection film or a film layer with specific transmittance, and one side far away from the fast axis focusing mirror and the slow axis focusing mirror is plated with a film layer with high reflection film or specific transmittance; the fast axis focusing lens, the slow axis focusing lens and the end face of the optical fiber are all plated with an antireflection film or an anti-reflection film.

Another aspect of the present disclosure provides a multi-single tube spectral beam combining structure, comprising: at least one laser chip, according to the preset angle setting, make the facula of every said laser chip arrange along the fast axis direction, and the optical path between diffraction grating and every said laser chip is equal; the fast axis collimating lens and the slow axis collimating lens are sequentially arranged on the light path between the laser chip and the diffraction grating and are respectively used for collimating the laser beam generated by the laser chip in the fast axis direction and the slow axis direction; a diffraction grating, the surface of which passes through the light paths of the at least one laser chip, wherein when the number of the laser chips is greater than 1, the surface of the diffraction grating passes through the intersection point of the light paths of the laser chips and is used for diffracting and combining the laser beams; and the external cavity mirror is arranged on the diffraction light path of the laser beam and is used for transmitting and outputting part of the diffracted laser beam and reflecting the other part of the diffracted laser beam so as to enable the laser beam to return to the laser chip through the diffraction grating.

Optionally, the method further comprises: a heat sink, the surface of which is a plane; the at least one laser chip is arranged on the heat sink.

Optionally, the light-emitting surface of the laser chip is plated with an antireflection film or a film layer with specific transmittance, and one side far away from the fast axis collimating mirror and the slow axis collimating mirror is plated with a film layer with high reflection film or specific transmittance; the fast axis collimating mirror, the slow axis collimating mirror and the diffraction grating are plated with an antireflection film or an anti-reflection film; the surface of the outer cavity mirror is plated with an antireflection film or a film layer with specific reflectivity.

Optionally, the surface form of the external cavity mirror at least comprises a plane mirror and a cylindrical mirror.

Optionally, the diffraction grating includes at least a transmissive diffraction grating, a reflective diffraction grating, a surface grating, and a bulk grating.

The above at least one technical scheme adopted in the embodiment of the disclosure can achieve the following beneficial effects:

The embodiment of the disclosure provides an aplanatic semiconductor laser beam combining structure and a multi-single-tube spectrum beam combining structure, wherein a plurality of laser chips are arranged along the fast axis direction, each laser chip rotates 90 degrees relative to the placement mode in the conventional structure, namely, the light beams in the fast axis direction and the slow axis direction of each laser chip are overturned, and the effect that light spots of a plurality of light beams are arranged along the fast axis direction is directly obtained; after the light beams in two directions generated by the laser chips are focused or collimated by the fast and slow axis focusing mirrors or the collimating mirrors respectively, the light spot size in the fast axis direction is smaller, and the light beam quality in the fast axis direction is higher, so that when the laser beam combining is carried out, the light spots of a plurality of laser chips are arranged along the fast axis direction, thereby being beneficial to balancing the light spot sizes and the light beam quality in the two directions of the output laser, and being easier to carry out light beam shaping, coupling into an optical fiber and the like.

Drawings

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1A schematically illustrates a side view of an aplanatic semiconductor laser beam combining structure provided by an embodiment of the present disclosure;

FIG. 1B schematically illustrates a top view of an aplanatic semiconductor laser beam combining structure provided by embodiments of the present disclosure;

Fig. 2A schematically illustrates a schematic diagram of a heat sink provided by an embodiment of the present disclosure;

fig. 2B schematically illustrates a schematic diagram of another heat sink provided by an embodiment of the present disclosure;

FIG. 3A schematically illustrates a side view of a multi-single tube spectral beam combining structure provided by an embodiment of the present disclosure;

Fig. 3B schematically illustrates a top view of a multi-single tube spectral beam combining structure according to another embodiment of the present disclosure.

Reference numerals illustrate:

10-a laser chip; 20-a fast axis focusing mirror; 30-a slow axis focusing mirror; 40-optical fiber; 50-a fast axis collimator lens; 60-a slow axis collimating mirror; a 70-diffraction grating; 80-external cavity mirror.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is only exemplary and is not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the concepts of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and/or the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.

The embodiment of the disclosure provides an aplanatic semiconductor laser beam combining structure, which comprises: at least one laser chip 10, a fast axis focusing mirror 20, a slow axis focusing mirror 30 and an optical fiber 40. Wherein, at least one laser chip 10 is symmetrically arranged relative to the optical fiber 40 according to a preset angle, so that the light spots of each laser chip 10 are arranged along the fast axis direction, and the optical paths between each laser chip 10 and the optical fiber 40 are equal; the fast axis focusing mirror 20 and the slow axis focusing mirror 30 are sequentially arranged on the light path between the laser chip 10 and the optical fiber 40, and are respectively used for focusing the laser beam generated by the laser chip 10 in the fast axis direction and the slow axis direction; the optical fiber 40 is disposed on the symmetry axis of at least one laser chip 10, and an end face of one end is used for receiving the focused laser beams, wherein when the number of the laser chips 10 is greater than 1, the end face is disposed at the intersection point of the optical paths of the laser chips 10.

The thickness of the active region of a typical semiconductor laser is only about 1 μm, but the width of the active region reaches about 50 μm to 200 μm, so that the light emitting surface of the active region is in a long and narrow rectangle. When the output beam of the semiconductor laser is output from the light emitting surface, there is a diffraction effect: the size of the active region in the fast axis direction, namely in the direction vertical to the PN junction is smaller, the diffraction effect is stronger, the beam divergence angle in the direction is larger, about 30-40 degrees, the light field is in the Gaussian distribution of the fundamental mode, the beam quality is good, and the diffraction limit is approached; the size of the active region in the slow axis direction, namely in the direction parallel to the PN junction is larger, and the diffraction effect is weaker, so that the beam divergence angle in the direction is relatively smaller, about 6-12 degrees, the optical field is multimode hermite-Gaussian distribution, and the beam quality is relatively poorer.

According to the aplanatic semiconductor laser beam combining structure provided by the embodiment of the disclosure, after the light beams are focused by the fast axis focusing mirror 20 and the slow axis focusing mirror 30 respectively, the light spot size in the fast axis direction is smaller, and the light beam quality in the fast axis direction is higher, so that when laser beam combining is performed, the light spots of the plurality of laser chips 10 are arranged along the fast axis direction, which is beneficial to balancing the light spot sizes and the light beam qualities in the two directions of output laser, and is easier to perform beam shaping, couple into the optical fiber 40 and the like.

In the conventional fiber coupling module, a plurality of laser chips are mostly arranged along the slow axis direction. In the aplanatic semiconductor laser beam combining structure provided in the embodiment of the disclosure, the plurality of laser chips 10 are arranged along the fast axis direction, each laser chip 10 rotates 90 ° relative to the placement mode in the conventional structure, that is, the light beams in the fast axis direction and the slow axis direction of each laser chip 10 are turned over, so that the effect of arranging the light spots of the plurality of light beams along the fast axis direction is directly obtained, and the aplanatic semiconductor laser beam combining structure is different from the effect of arranging the light spots of the plurality of light beams along the slow axis direction in the conventional beam combining scheme, and each laser chip 10 is symmetrical along the central axis, and has certain inclination angles on two sides, so that the optical path between each laser chip 10 and the optical fiber 40 is equal.

Fig. 1A and 1B schematically illustrate a side view and a top view, respectively, of an aplanatic semiconductor laser beam combining structure provided by an embodiment of the present disclosure.

As shown in fig. 1A and 1B, in this embodiment, the laser chips 10 may be single laser tubes, the number of which is 3, and are symmetrically arranged with respect to the optical fiber 40 according to a preset angle, so that the light spots of each laser chip 10 are arranged along the fast axis direction, and the optical paths between each laser chip 10 and the optical fiber 40 are equal; the fast axis focusing mirror 20 and the slow axis focusing mirror 30 are sequentially arranged on the light path between the laser chip 10 and the optical fiber 40, and are respectively used for focusing the laser beam generated by the laser chip 10 in the fast axis direction and the slow axis direction; the optical fiber 40 is disposed on the symmetry axis of the 3 laser chips 10, and the end face of one end is used for receiving the focused laser beam, and the end face is disposed at the intersection point of the optical paths of the 3 laser chips 10, so that the coupling efficiency can be improved. Finally, the beam of light combined in the optical fiber 40 will exit along the end of the optical fiber 40.

The laser chip 10 of the embodiment of the present disclosure is exemplified by, but not limited to, a semiconductor laser chip, and may be a semiconductor optical amplifier, a J-waveguide laser chip, a photonic crystal laser chip, or the like.

In this embodiment, the light emitting surface of the laser chip 10 is coated with an antireflection film or a film layer with specific transmittance, and the side far away from the fast axis focusing mirror 20 and the slow axis focusing mirror 30 is coated with a film layer with high reflectance or specific transmittance; the end surfaces of the fast axis focusing mirror 20, the slow axis focusing mirror 30 and the optical fiber 40 are all coated with an antireflection film or an antireflection film.

Alternatively, the fast axis focusing mirror 20 and the slow axis focusing mirror 30 are microlenses with a better degree of focusing and less influence on the beam quality, including but not limited to one of the following focusing mirror type forms: spherical focusing mirror, aspherical focusing mirror, self-focusing mirror, cylindrical focusing mirror, annular lens or aspherical reflecting focusing mirror, etc.

Alternatively, the fast axis focusing mirror 20 and the slow axis focusing mirror 30 are not necessarily separate two lenses, but may be a single lens or a lens group to achieve similar effects, in order to focus the fast and slow axes of the light beam.

Aiming at the aplanatic semiconductor laser beam combining structure provided by the embodiment of the disclosure, the embodiment of the disclosure also provides a novel heat sink.

Fig. 2A schematically illustrates a schematic diagram of a heat sink provided by an embodiment of the present disclosure.

As shown in fig. 2A, the surface of the heat sink provided by the embodiment of the present disclosure is a plane, and the laser chip 10 is disposed on the heat sink. A plurality of laser chip 10 fixing blocks are arranged on the surface of the heat sink and are arranged at the corresponding positions of the laser chips 10 for fixing the laser chips 10. Fig. 2A schematically shows 3 laser chip 10 fixing blocks, which are arranged in the same arrangement position and angle as the laser chips 10, along the fast axis direction, and at an oblique angle so that the optical paths between the respective laser chips 10 and the optical fibers 40 are equal.

The heat sink shown in fig. 2A is only one illustrative form and many variations are possible in practice.

Optionally, each place on the heat sink where the chip is placed may be grooved to facilitate solder flow without spilling to contaminate the cavity or short circuit the chip.

Fig. 2B schematically illustrates a schematic diagram of another heat sink provided by an embodiment of the present disclosure.

As shown in fig. 2B, on the basis of the novel heat sink shown in fig. 2A, the heat sink provided in the embodiment of the present disclosure may further include an optical fiber fixing block, and a groove is provided on a surface of the optical fiber fixing block for fixing the optical fiber 40. The optical fiber fixing block is arranged on the symmetry axis of the lasers corresponding to the position of the optical fiber 40 so as to fix the optical fiber 40 on the symmetry axis of each laser.

The novel heat sink provided by the embodiment of the disclosure does not need to design a step height difference on the heat sink, and the requirement on processing precision can be relatively reduced; because the optical paths from each laser chip to the optical fiber are equal, the focusing lens can be directly used for focusing the fast axis direction light beam and the slow axis direction light beam of the laser chip respectively, and the light beams are coupled into the optical fiber for transmission, so that the collimation of the light beams is not needed, the cost is reduced, the time is saved, and the adjustment difficulty is reduced; the reflector is not needed to rearrange the light spots, and the effect that the light spots of a plurality of light beams are arranged in the fast axis direction can be directly obtained.

According to the aplanatic semiconductor laser beam combining structure provided by the embodiment of the disclosure, the laser chips 10 and the optical fibers 40 are fixed on the heat sink, the process of rotating the fast axis and the slow axis of the light beam by using the light beam conversion system (Beam Transformation System, BTS) is omitted, the lens is simple to mount and adjust, and the effect that the light beams of a plurality of laser chips 10 are arranged in the fast axis direction can be directly realized; the resulting output laser beam quality due to spectral combination is substantially comparable to the beam quality of the individual laser chips 10. Compared with the bar, the single tube has simple process operation and relatively low heat dissipation requirement, and no 'smile' effect exists, so that the beam quality of a single laser chip 10 on the single tube is generally higher than that of a single laser unit on Yu Ba bars, and the beam combination structure can obtain higher beam quality and can meet the harsh requirements of some application fields.

In this embodiment, some other optical elements may be added to the aplanatic semiconductor laser beam combining structure to achieve a specific function. Such as adding a volume bragg grating, the effects of narrowing the spectrum width, wavelength locking, etc. can be realized.

The beam combining mode adopted by the embodiment of the disclosure is not only suitable for the edge emitting laser, but also suitable for the vertical cavity surface emitting laser, and the beam combining structure can still realize the function as long as the direction and the position of the placement of the heat sink are properly modified.

Another aspect of the present disclosure provides a multi-single tube spectral beam combining structure, comprising: at least one laser chip 10, a fast axis collimator 50, a slow axis collimator 60, a diffraction grating 70, and an external cavity mirror 80. Wherein, at least one laser chip 10 is arranged according to a preset angle, so that the light spots of each laser chip 10 are arranged along the fast axis direction, and the optical paths between each laser chip 10 and the diffraction grating 70 are equal; the fast axis collimating mirror 50 and the slow axis collimating mirror 60 are sequentially arranged on the light path between the laser chip 10 and the diffraction grating 70, and are respectively used for collimating the laser beam generated by the laser chip 10 in the fast axis direction and the slow axis direction; the surface of the diffraction grating 70 passes through the light path of at least one laser chip 10, wherein when the number of the laser chips 10 is greater than 1, the surface of the diffraction grating 70 passes through the intersection point of the light paths of the laser chips 10, and is used for diffracting and combining the laser beams; the external cavity mirror 80 is disposed on the diffraction path of the laser beam, and is configured to transmit a part of the diffracted laser beam and output the transmitted laser beam, and reflect another part of the diffracted laser beam, so that the diffracted laser beam returns to the laser chip 10 through the diffraction grating 70.

The multiple laser chips of the multi-single-tube spectrum beam combining structure are arranged along the fast axis direction, so that the process of rotating fast and slow axes of light beams by using BTS (base transceiver station) can be omitted; the multiple light beams can be converged on the grating without adopting a conversion lens, the lens assembly and adjustment are simpler, and the effect that the light beams of the multiple laser chips are arranged along the fast axis direction can be directly realized; by changing the distance and the included angle between the heat sinks of the chips and the distance between the central heat sink and the grating, the incident angle of each laser chip relative to the grating can be different, so that the grating equation is satisfied, and the optical path can be shortened compared with the conventional structure (when a conversion lens is used in the conventional structure, the distance from the laser chip to the conversion lens is required to be equal to the distance from the conversion lens to the grating).

The multi-single-tube spectrum beam combining structure arranges a plurality of laser chips along the fast axis direction, and each laser chip rotates 90 degrees relative to the placement mode in the conventional structure, namely, the light beams in the fast axis direction and the slow axis direction of each laser chip are overturned, and the effect that the light spots of the plurality of light beams are arranged along the fast axis direction is directly obtained. After the light beams in two directions generated by each laser chip 10 are respectively collimated by the fast axis collimator lens 60 and the slow axis collimator lens 60, the light spot size in the fast axis direction is smaller, and the light beam quality in the fast axis direction is higher, so that when the laser beam combining is performed, the light spots of the plurality of laser chips 10 are arranged along the fast axis direction, which is beneficial to balancing the light spot sizes and the light beam qualities in the two directions of the output laser, and the light beam shaping and the coupling into the optical fiber 40 are easier to perform.

Fig. 3A and 3B schematically illustrate a side view and a top view, respectively, of a multi-single tube spectral beam combining structure provided by an embodiment of the present disclosure.

As shown in fig. 3A and 3B, in this embodiment, the multi-single-tube spectrum beam combining structure includes 3 laser chips 10 as an example, where the multiple laser chips 10 are sequentially disposed along the fast axis direction, the fast axis direction and the slow axis direction of the light beam are first collimated by the fast axis collimating mirror 50 and the slow axis collimating mirror 60, and then the laser output after passing through the diffraction grating 70 along the light path exits at the same diffraction angle, and only the laser satisfying the grating constant, the incident angle, the diffraction order and the incident wavelength relationship of the laser in the grating diffraction equation can form effective resonance, and after passing through the external cavity mirror 80, the laser can be partially reflected back to the original laser chip to continue oscillation, and the laser output is partially transmitted.

The laser chip 10 of the embodiment of the present disclosure is exemplified by, but not limited to, a semiconductor laser chip, and may be a semiconductor optical amplifier, a J-waveguide laser chip, a photonic crystal laser chip, or the like.

In this embodiment, the light-emitting surface of the laser chip 10 is coated with an antireflection film or a film layer with specific transmittance, and one side far away from the fast axis collimating mirror 50 and the slow axis collimating mirror 60 is coated with a film layer with high reflectance or specific transmittance; the fast axis collimating mirror 50, the slow axis collimating mirror 60 and the diffraction grating 70 are all coated with an antireflection film or an antireflection film; the surface of the external cavity mirror 80 is coated with an antireflection film or a film layer of a specific reflectance.

Alternatively, the fast axis collimator 50 and the slow axis collimator 60 are microlenses with better collimation and less impact on beam quality, including but not limited to one of the following collimator forms: spherical collimating lens, aspherical collimating lens, auto-focusing collimating lens, cylindrical collimating lens, annular lens or aspherical reflecting collimating lens.

Alternatively, the fast axis collimator 50 and the slow axis collimator 60 need not be separate two lenses, but may be a single lens or a lens group to achieve similar effects, in order to collimate the fast and slow axes of the light beam.

In this embodiment, the surface shape of the external cavity mirror 80 may be a plane mirror, a cylindrical mirror, or the like.

In the present embodiment, the transmission of the light beam is exemplified by the transmission type diffraction grating 70, and optionally, the diffraction grating 70 may further include, but is not limited to, a transmission type diffraction grating, a reflection type diffraction grating, a surface grating, a bulk grating, or the like.

In this embodiment, the multi-single-tube spectrum beam combining structure may further include a heat sink, the surface of which is a plane, and the laser chip 10 is disposed on the heat sink. Preferably, the laser chip 10 is a single tube. Compared with the bar, the single tube has simple process operation and relatively low heat dissipation requirement, and no 'smile' effect exists, so that the beam quality of a single laser chip 10 on the single tube is generally higher than that of a single laser unit on Yu Ba bars, and the beam combination structure can obtain higher beam quality and can meet the harsh requirements of some application fields. The adjustment accuracy requirement of the bar alignment straight array mirror is higher, and the adjustment accuracy requirement of the single tube alignment straight array mirror is lower.

The multiple laser chips of the multi-single-tube spectrum beam combining structure provided by the embodiment of the disclosure are arranged along the fast axis direction, the step of using BTS to rotate the light beam is omitted, the fast axis arrangement is directly realized, and in addition, the fast axis light beam quality is better, the light beam quality of the output laser in two directions can be balanced, the light beam shaping is easier to carry out, even the coupling into the optical fiber is easier, and the like. The system does not need to use a transmission lens, and can reduce the volume of the system. When the laser chip adopts a single tube, the smile effect can be avoided, and the adjustment precision requirement of the alignment straight array mirror is not high.

Those skilled in the art will appreciate that the features recited in the various embodiments of the disclosure and/or in the claims may be provided in a variety of combinations and/or combinations, even if such combinations or combinations are not explicitly recited in the disclosure. In particular, the features recited in the various embodiments of the present disclosure and/or the claims may be variously combined and/or combined without departing from the spirit and teachings of the present disclosure. All such combinations and/or combinations fall within the scope of the present disclosure.

While the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. The scope of the disclosure should, therefore, not be limited to the above-described embodiments, but should be determined not only by the following claims, but also by the equivalents of the following claims.

Claims (10)

1. An aplanatic semiconductor laser beam combining structure, comprising:

At least one laser chip (10) is symmetrically arranged relative to the optical fiber (40) according to a preset angle, so that light spots of each laser chip (10) are arranged along the fast axis direction, and optical paths between each laser chip (10) and the optical fiber (40) are equal;

a fast axis focusing mirror (20) and a slow axis focusing mirror (30) which are sequentially arranged on the light path between the laser chip (10) and the optical fiber (40) and are respectively used for focusing the laser beam generated by the laser chip (10) in the fast axis direction and the slow axis direction;

And the optical fiber (40) is arranged on the symmetry axis of the at least one laser chip (10), and the end face of one end is used for receiving the focused laser beams, wherein when the number of the laser chips (10) is greater than 1, the end face is arranged at the intersection point of the optical paths of the laser chips (10).

2. The aplanatic semiconductor laser beam combining structure of claim 1, further comprising:

A heat sink, the surface of which is a plane;

the at least one laser chip (10) is arranged on the heat sink.

3. The aplanatic semiconductor laser beam combining structure of claim 2, wherein the heat sink further comprises:

And the laser chip (10) fixing block is arranged at a position corresponding to the laser chip (10) and used for fixing the laser chip (10).

4. The aplanatic semiconductor laser beam combining structure of claim 2, wherein the heat sink further comprises:

and the surface of the optical fiber fixing block is provided with a groove for fixing the optical fiber (40).

5. The aplanatic semiconductor laser beam combining structure according to claim 1, wherein the light emitting surface of the laser chip (10) is coated with an antireflection film or a film layer with specific transmittance, and one side far away from the fast axis focusing mirror (20) and the slow axis focusing mirror (30) is coated with a film layer with high reflection film or specific transmittance; the fast axis focusing lens (20), the slow axis focusing lens (30) and the end face of the optical fiber (40) are plated with an antireflection film or an anti-reflection film.

6. A multi-single tube spectral beam combining structure, comprising:

At least one laser chip (10) arranged according to a preset angle, so that light spots of each laser chip (10) are arranged along the fast axis direction, and optical paths between each laser chip (10) and the diffraction grating (70) are equal;

The fast axis collimating lens (50) and the slow axis collimating lens (60) are sequentially arranged on a light path between the laser chip (10) and the diffraction grating (70) and are respectively used for collimating the laser beam generated by the laser chip (10) in the fast axis direction and the slow axis direction;

A diffraction grating (70) having a surface passing through the optical paths of the at least one laser chip (10), wherein when the number of the laser chips (10) is greater than 1, the surface of the diffraction grating (70) passes through the intersection point of the optical paths of the laser chips (10) for diffracting and combining the laser beams;

And an external cavity mirror (80) which is arranged on the diffraction optical path of the laser beam and is used for transmitting and outputting part of the diffracted laser beam and reflecting the other part of the diffracted laser beam to return to the laser chip (10) through the diffraction grating (70).

7. The multi-single tube spectral beam-combining structure of claim 6, further comprising:

A heat sink, the surface of which is a plane;

The at least one laser chip (10) is arranged on the heat sink.

8. The multi-single-tube spectrum beam combining structure according to claim 6, wherein the light-emitting surface of the laser chip (10) is coated with an antireflection film or a film layer with specific transmittance, and one side far away from the fast axis collimating mirror (50) and the slow axis collimating mirror (60) is coated with a film layer with high reflection film or specific transmittance; the fast axis collimating mirror (50), the slow axis collimating mirror (60) and the diffraction grating (70) are all plated with an antireflection film or an anti-reflection film; the surface of the outer cavity mirror (80) is plated with an antireflection film or a film layer with specific reflectivity.

9. The multi-single tube spectral beam combining structure according to claim 6, wherein the facets of the external cavity mirror (80) comprise at least a plane mirror and a cylindrical mirror.

10. The multi-single tube spectral beam-combining structure according to claim 6, wherein the diffraction grating (70) comprises at least a transmissive diffraction grating, a reflective diffraction grating, a surface grating and a bulk grating.