阅读说明：本技术 一种半导体激光器部分相干合束系统 (Partial coherent beam combination system of semiconductor laser ) 是由 俞浩 虞天成 李泉灵 王俊 潘华东 于 2020-12-25 设计创作，主要内容包括：一种半导体激光器部分相干合束系统,包括：第一半导体激光芯片至第N半导体激光芯片,第k半导体激光芯片出射第k激光,第一激光至第N激光进行空间合束形成空间合束激光,N为大于等于2的整数,k大于等于1且小于等于N；光纤,所述光纤的入射端具有部分反射膜层；聚焦耦合镜,所述聚焦耦合镜适于将所述空间合束激光中的第一激光至第N激光耦合进所述光纤；所述部分反射膜层反射部分第k激光,使得被反射的第k激光经过聚焦耦合镜之后注入第N－k+1半导体激光芯片。所述半导体激光器部分相干合束系统实现部分相干的合束输出,光束质量提高,并最终通过光纤输出。(A semiconductor laser partial coherent beam combining system comprising: the laser device comprises a first semiconductor laser chip, a second semiconductor laser chip, a third semiconductor laser chip, a fourth semiconductor laser chip, a fifth semiconductor laser chip, a sixth semiconductor laser chip and a sixth semiconductor laser chip, wherein the first semiconductor laser chip to the nth semiconductor laser chip emit kth laser, the first laser to the nth laser are spatially combined to form spatially combined laser, N is an integer greater than or equal to 2, and k is greater than or equal to 1 and less than or equal to N; the incident end of the optical fiber is provided with a partial reflection film layer; a focusing coupling mirror adapted to couple first through Nth lasers of the spatially combined laser light into the optical fiber; the partial reflection film layer reflects partial kth laser, so that the reflected kth laser passes through the focusing coupling mirror and then is injected into the N-k +1 semiconductor laser chip. The semi-coherent beam combination system of the semiconductor laser realizes the output of partially coherent combined beams, improves the quality of light beams and finally outputs the light beams through optical fibers.)

1. A semiconductor laser partial coherence beam combining system, comprising:

the laser device comprises a first semiconductor laser chip, a second semiconductor laser chip, a third semiconductor laser chip, a fourth semiconductor laser chip, a fifth semiconductor laser chip, a sixth semiconductor laser chip and a sixth semiconductor laser chip, wherein the first semiconductor laser chip to the nth semiconductor laser chip emit kth laser, the first laser to the nth laser are spatially combined to form spatially combined laser, N is an integer greater than or equal to 2, and k is greater than or equal to 1 and less than or equal to N;

the incident end of the optical fiber is provided with a partial reflection film layer;

the focusing coupling mirror is suitable for coupling first laser to Nth laser in the space beam combination laser into the optical fiber, and the focusing coupling mirror faces to an incident end of the optical fiber;

the partial reflection film layer reflects partial kth laser, so that the reflected kth laser passes through the focusing coupling mirror and then is injected into the N-k +1 semiconductor laser chip.

2. The semiconductor laser partial coherence beam combining system of claim 1, wherein the reflectivity of the partially reflective film layer is 5% to 15%.

3. The semiconductor laser partial coherence beam combining system of claim 1, wherein the partially reflective film layer is a narrow-band partially reflective film, the narrow-band partially reflective film reflects laser light of a characteristic wavelength, and a wavelength width of the laser light of the characteristic wavelength is less than or equal to 1 nm.

4. The semiconductor laser partial coherence beam combining system of claim 1, wherein the focusing coupling mirror has a central optical axis passing through a focal point of the focusing coupling mirror; the first laser to the Nth laser in the space beam combination laser are parallel to the central optical axis, and the kth laser and the (N-k +1) th laser in the space beam combination laser are symmetrically arranged around the central optical axis.

5. The semiconductor laser partial coherence beam combining system of claim 1, wherein the focusing coupling mirror has a central optical axis passing through a focal point of the focusing coupling mirror; the central axis of the optical fiber is coincided with the central optical axis of the focal point of the focusing coupling mirror, and the focal point of the focusing coupling mirror is positioned on the surface of the partial reflection film layer.

6. The semiconductor laser partially coherent beam combining system of claim 1, wherein the kth semiconductor laser chip has a kth front facet adapted to emit kth laser light, the kth front facet is provided with a kth front facet coating, and a reflectivity of the kth front facet coating is less than or equal to 2%.

7. The semiconductor laser partial coherence beam combining system of claim 1, wherein the emitting directions of the first semiconductor laser chip to the Nth semiconductor laser chip are parallel.

8. The semiconductor laser partial coherent beam combining system of claim 1, further comprising: the first collimating unit to the Nth collimating unit, the kth collimating unit is suitable for collimating the kth laser emitted by the kth semiconductor laser chip.

9. The semiconductor laser partial coherent beam combining system of claim 8, wherein the kth collimating unit comprises a kth fast axis collimating unit and a kth slow axis collimating unit.

10. The semiconductor laser partial coherent beam combining system of claim 1, wherein N is odd or even.

Technical Field

The invention relates to the field of semiconductors, in particular to a semiconductor laser partial coherent beam combination system.

Background

The high-power semiconductor laser fiber coupling module is widely applied to the pumping field of fiber laser and solid laser at present due to higher electro-optic conversion efficiency, smaller volume, higher reliability and lower price per watt.

Semiconductor lasers are generally assembled into fiber coupling modules through processes of beam shaping, spatial beam combination, fiber coupling and the like, and can be applied to practical applications. Spatial beam combining, while increasing output power, sacrifices beam quality. Meanwhile, due to the specific property of the semiconductor laser, the output wavelength can generate certain drift along with the temperature current, and the pumping efficiency is reduced. The above disadvantages cause the fiber coupling module to have certain defects in the practical application process.

Disclosure of Invention

The invention aims to solve the technical problem of poor quality of beam combination laser in the prior art.

In order to solve the above technical problem, the present invention provides a partial coherent beam combining system of a semiconductor laser, comprising: the laser device comprises a first semiconductor laser chip, a second semiconductor laser chip, a third semiconductor laser chip, a fourth semiconductor laser chip, a fifth semiconductor laser chip, a sixth semiconductor laser chip and a sixth semiconductor laser chip, wherein the first semiconductor laser chip to the nth semiconductor laser chip emit kth laser, the first laser to the nth laser are spatially combined to form spatially combined laser, N is an integer greater than or equal to 2, and k is greater than or equal to 1 and less than or equal to N; the incident end of the optical fiber is provided with a partial reflection film layer; the focusing coupling mirror is suitable for coupling first laser to Nth laser in the space beam combination laser into the optical fiber, and the focusing coupling mirror faces to an incident end of the optical fiber; the partial reflection film layer reflects partial kth laser, so that the reflected kth laser passes through the focusing coupling mirror and then is injected into the N-k +1 semiconductor laser chip.

Optionally, the reflectivity of the partially reflective film layer is 5% to 15%.

Optionally, the partial reflection film layer is a narrow-band partial reflection film, the narrow-band partial reflection film reflects laser with a characteristic wavelength, and a wavelength width of the laser with the characteristic wavelength is less than or equal to 1 nm.

Optionally, the focusing coupling mirror has a central optical axis passing through a focal point of the focusing coupling mirror; the first laser to the Nth laser in the space beam combination laser are parallel to the central optical axis, and the kth laser and the (N-k +1) th laser in the space beam combination laser are symmetrically arranged around the central optical axis.

Optionally, the focusing coupling mirror has a central optical axis passing through a focal point of the focusing coupling mirror; the central axis of the optical fiber is coincided with the central optical axis of the focal point of the focusing coupling mirror, and the focal point of the focusing coupling mirror is positioned on the surface of the partial reflection film layer.

Optionally, the kth semiconductor laser chip has a kth front cavity surface, the kth front cavity surface is suitable for emitting kth laser, the kth front cavity surface is provided with a kth front cavity coating, and the reflectivity of the kth front cavity coating is less than or equal to 2%.

Optionally, the directions of the laser beams emitted from the first semiconductor laser chip to the nth semiconductor laser chip are parallel.

Optionally, the method further includes: the first collimating unit to the Nth collimating unit, the kth collimating unit is suitable for collimating the kth laser emitted by the kth semiconductor laser chip.

Optionally, the kth collimating unit includes a kth fast axis collimating unit and a kth slow axis collimating unit.

Optionally, N is an odd or even number.

The technical scheme of the invention has the following advantages:

in the partial coherent beam combination system of the semiconductor laser provided by the technical scheme of the invention, a plurality of random wavelength, phase and intensity modes exist when the kth semiconductor laser chip starts to work, when the kth laser emitted by the kth semiconductor laser chip is coherent with the (N-k +1) th laser emitted by the (N-k +1) th semiconductor laser chip, the partial coherent mode is reflected back to the corresponding laser chip to be strengthened due to the existence of the partial reflection film layer, so that a mode competition advantage is formed in the gain material in the corresponding laser chip, other incoherent modes disappear finally, only coherent modes can be generated in the kth semiconductor laser chip and the (N-k +1) th semiconductor laser chip, finally, the optical fiber can realize the output of a partially coherent combined beam, and the quality of the light beam output by the optical fiber can be doubled.

Further, the partial reflection film layer is a narrow-band partial reflection film, the narrow-band partial reflection film reflects laser with characteristic wavelength, and finally the optical fiber can realize partially coherent wavelength locking and narrowed output.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of a partially coherent beam combining system of a semiconductor laser according to an embodiment of the present invention.

Detailed Description

An embodiment of the present invention provides a partial coherent beam combining system for a semiconductor laser, and with reference to fig. 1, the system includes:

first semiconductor laser chip G₁To Nth semiconductor laser chip G_nKth semiconductor laser chip G_kEmitting a kth laser, and carrying out spatial beam combination on the first laser to the Nth laser to form a spatial beam combination laser, wherein N is an integer greater than or equal to 2, and k is greater than or equal to 1 and less than or equal to N;

an optical fiber 120, an incident end of the optical fiber 120 having a partially reflective film layer 121;

a focusing coupling mirror 130, wherein the focusing coupling mirror 130 is adapted to couple the first laser light to the nth laser light in the spatially combined laser light into the optical fiber 120, and the focusing coupling mirror 130 faces an incident end of the optical fiber 120;

the partially reflective film layer 121 reflects a portion of the kth laser beam, such that the reflected kth laser beam passes through the focusing coupling mirror 130 and is injected into the N-k +1 th semiconductor laser chip G_N-k+1。

In this embodiment, the value of N may be reasonably selected according to needs, and is not limited herein. N is even or odd. Preferably, N is an odd number, and the corresponding (N +1)/2 th laser light passes through the central optical axis of the focusing coupling mirror 130.

The partially reflective film 121 is adapted to reflect a portion of the light beam of the k-th laser light, and a majority of the light beam of the k-th laser light enters the optical fiber through the partially reflective film 121.

The reflectivity of the partially reflective film layer 121 is 5% to 15%. The significance of the reflectivity of the partially reflective film layer 121 is: if the reflectivity of the partial reflection film layer 121 is less than 5%, the reflection of the k-th laser light is less, the energy of the reflected k-th laser light is less, the coherent action between the reflected k-th laser light and the N-k + 1-th laser light in the N-k + 1-th semiconductor laser chip is less, and the mode competition advantage of the partial coherent mode formed in the gain material in the corresponding laser chip is weaker; if the reflectivity of the partially reflective film layer 121 is greater than 15%, the k-th laser light passing through the partially reflective film layer 121 is reduced, which results in a reduction in the power of the laser light output from the output end of the final optical fiber.

The focusing coupling mirror 130 has a central optical axis passing through a focal point of the focusing coupling mirror 130; the first laser and the Nth laser in the space beam combination laser are both parallel to the central optical axis, and the kth laser and the (N-k +1) th laser in the space beam combination laser are symmetrically arranged around the central optical axis.

The central axis of the optical fiber 120 coincides with the central optical axis of the focal point of the focusing coupling mirror 130, and the focal point of the focusing coupling mirror 130 is located on the surface of the partially reflective film layer 121.

The semiconductor laser partial coherent beam combination system further comprises: a first collimating unit to an Nth collimating unit, the k-th collimating unit being adapted to be coupled toKth semiconductor laser chip G_kThe emitted kth laser light is collimated. In this embodiment, spatial beam combination is performed on the collimated first laser light to the collimated nth laser light.

In this embodiment, the kth collimating unit includes a kth fast axis collimating lens and a kth slow axis collimating lens, and the kth fast axis collimating lens and the kth slow axis collimating lens sequentially face the kth semiconductor laser chip G_kThe emitted kth laser light is collimated. That is, after the k-th fast axis collimating lens collimates the k-th laser, the k-th slow axis collimating lens collimates the k-th laser. The kth fast axis collimating lens is positioned between the kth slow axis collimating lens and the kth semiconductor laser chip.

In other embodiments, the kth collimating unit includes only the kth slow-axis collimating lens, or the kth collimating unit includes only the kth fast-axis collimating lens.

The kth semiconductor laser chip G_kThe laser cavity comprises a kth front cavity surface and a kth rear cavity surface, wherein the kth front cavity surface is opposite to the kth front cavity surface, the kth front cavity surface is suitable for emitting kth laser, a kth front cavity coating layer is arranged on the kth front cavity surface, a kth rear cavity coating layer is arranged on the kth rear cavity surface, and the reflectivity of the kth rear cavity coating layer is larger than that of the kth front cavity coating layer. In the embodiment, the reflectivity of the coating layer of the kth back cavity is more than 99%; the reflectivity of the k-th front cavity coating layer is less than or equal to 2 percent.

First semiconductor laser chip G₁To Nth semiconductor laser chip G_nThe directions of the emitted laser beams are parallel. In one embodiment, the first semiconductor laser chip G₁To Nth semiconductor laser chip G_nIn the direction of emitting laser light, the first semiconductor laser chip G₁To Nth semiconductor laser chip G_nFront-to-back staggered first semiconductor laser chip G₁To Nth semiconductor laser chip G_nThe projections of the edges of adjacent semiconductor laser chips can partially coincide. In the collimation direction of the first to the Nth slow axis collimating lenses to the laser, the first to the Nth slow axis collimating lenses are staggered front and back, so that the projections of the edges of the first to the Nth slow axis collimating lenses can be partially overlapped, and the first laser and the Nth laser are enabled to be partially overlappedThe distance between adjacent lasers in the Nth laser is tighter, so that the value of N can be larger, and finally the output power of the optical fiber is improved.

It should be noted that the k-th fast axis collimating lens is generally disposed adjacent to the k-th semiconductor laser chip G_kThe light outlet of (2).

In this embodiment, the first to nth lasers are focused on the focal point of the focusing coupling mirror 130 through the focusing coupling mirror 130, that is, the input ends of the optical fibers are located at the beam waist of the gaussian beam, and the first to nth lasers are partially reflected by the partially reflective film layer 121, specifically, the partially reflective film layer 121 reflects a part of the kth laser, so that the reflected kth laser is injected into the N-k +1 th semiconductor laser chip G after passing through the focusing coupling mirror 130_N-k+1。

For the first semiconductor laser chip G₁The first laser and the Nth semiconductor laser chip G are emitted_NThe emitted nth laser light, the partial reflection film layer 121 reflects a portion of the first laser light, and the first laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the nth semiconductor laser chip G_NThe partially reflective film 121 reflects a portion of the nth laser beam, and the nth laser beam reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and is injected into the first semiconductor laser chip G₁。

When N is greater than or equal to 2, for the second semiconductor laser chip G₂The second laser and the N-1 semiconductor laser chip G_N-1The emitted N-1 laser, the partially reflective film 121 reflects a portion of the second laser, and the second laser reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the N-1 semiconductor laser chip G_N-1The partially reflective film 121 reflects a portion of the N-1 th laser beam, and the N-1 th laser beam reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the second semiconductor laser chip G₂。

When N is 3 or more, for the third semiconductor laser chip G₃Emitting a third laser and an N-2 semiconductor laser chip G_N-2Emitting an N-2 laser, the partial reflection film layer121 reflects part of the third laser light, and the third laser light reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the N-2 semiconductor laser chip G_N-2The partially reflective film 121 reflects a part of the N-2 th laser beam, and the N-2 th laser beam reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the third semiconductor laser chip G₃。

In a specific embodiment, the example where N is equal to 7 is illustrated for the first semiconductor laser chip G₁The first laser and the seventh semiconductor laser chip G₇The emitted seventh laser light, the partial reflection film layer 121 reflects part of the first laser light, and the first laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the seventh semiconductor laser chip G₇The partially reflective film 121 reflects part of the seventh laser beam, and the seventh laser beam reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the first semiconductor laser chip G₁For the second semiconductor laser chip G₂The second laser and the sixth semiconductor laser chip G₆The emitted sixth laser light, the partial reflection film layer 121 reflects part of the second laser light, and the second laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the sixth semiconductor laser chip G₆The partially reflective film 121 reflects a part of the sixth laser light, and the sixth laser light reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the second semiconductor laser chip G₂For the third semiconductor laser chip G₃The third laser and the fifth semiconductor laser chip G₅The emitted fifth laser light, the partial reflection film layer 121 reflects part of the third laser light, and the third laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the fifth semiconductor laser chip G₅The partially reflective film 121 reflects a portion of the fifth laser light, and the fifth laser light reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the third semiconductor laser chip G₃For the fourth semiconductor laser chip G₄A fourth laser beam emitted from the partially reflective film 121Light, the fourth laser light reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and is injected into the fourth semiconductor laser chip G₄。

Taking N equal to 9 as an example for the first semiconductor laser chip G₁The first laser and the ninth semiconductor laser chip G₉The emitted ninth laser light, the partial reflection film layer 121 reflects part of the first laser light, and the first laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the ninth semiconductor laser chip G₉The partially reflective film 121 reflects a part of the ninth laser beam, and the ninth laser beam reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the first semiconductor laser chip G₁For the second semiconductor laser chip G₂The second laser and the eighth semiconductor laser chip G₈The emitted eighth laser light, the partial reflection film layer 121 reflects part of the second laser light, and the second laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the eighth semiconductor laser chip G₈The partially reflective film 121 reflects a portion of the eighth laser beam, and the eighth laser beam reflected by the partially reflective film 121 passes through the focusing coupling mirror 130 and then is injected into the second semiconductor laser chip G₂For the third semiconductor laser chip G₃The third laser and the seventh semiconductor laser chip G₇The emitted seventh laser light, the partial reflection film layer 121 reflects part of the third laser light, and the third laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the seventh semiconductor laser chip G₇The partially reflective film 121 reflects part of the seventh laser beam, and the seventh laser beam reflected by the partially reflective film 121 passes through the focusing and coupling mirror 130 and then is injected into the third semiconductor laser chip G₃For the fourth semiconductor laser chip G₄The fourth laser and the sixth semiconductor laser chip G₆The emitted sixth laser light, the partial reflection film layer 121 reflects part of the fourth laser light, and the fourth laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the sixth semiconductor laser chip G₆A reflective part of the partially reflective film layer 121Dividing the sixth laser beam, injecting the sixth laser beam reflected by the partially reflective film 121 into the fourth semiconductor laser chip G after passing through the focusing coupling mirror 130₄For the fifth semiconductor laser chip G₅The emitted fifth laser light, the partial reflection film layer 121 reflects part of the fifth laser light, and the fifth laser light reflected by the partial reflection film layer 121 passes through the focusing coupling mirror 130 and then is injected into the fifth semiconductor laser chip G₅。

When N is chosen to be other, it operates according to a similar principle as described above and will not be described in detail.

In one embodiment, the partially reflective film layer 121 reflects all wavelengths of the k-th laser light. In another embodiment, the partially reflective film layer 121 is a narrow band partially reflective film.

In this embodiment, when the kth semiconductor laser chip starts to work, a plurality of random wavelength, phase and intensity modes may exist, and when the kth laser light emitted by the kth semiconductor laser chip and the N-k +1 th laser light emitted by the N-k +1 th semiconductor laser chip are coherent, the partially coherent mode may be reflected back to the corresponding laser chip to be enhanced due to the existence of the partially reflective film layer 121, so that a mode competition advantage is formed in the gain material in the corresponding laser chip, and finally, other incoherent modes may disappear, only coherent modes may exist in the kth semiconductor laser chip and the N-k +1 th semiconductor laser chip, and finally, the optical fiber may realize partially coherent combined beam output, and the beam quality output by the optical fiber may be doubled.

When the partially reflective film layer 121 is a narrow-band partially reflective film, the narrow-band partially reflective film reflects laser with a characteristic wavelength, and finally the optical fiber can realize partially coherent wavelength locking and narrowed output. The wavelength width of the laser with the characteristic wavelength is less than or equal to 1 nanometer. The partially reflective film layer 121 reflects laser light of a characteristic wavelength mainly emphasizes the reflection of laser light of a narrow wavelength range, and does not emphasize a specific wavelength value.

The reflectivity of the prior k-th front cavity coating is about 5 percent generally. The reflectivity of the k-th front cavity coating layer in the k-th semiconductor laser chip is reduced, and the reflectivity of the k-th front cavity coating layer is smaller than or equal to 2%, so that the k-th laser which is helpful to being reflected can win the competition of modes, and a better wavelength locking effect is achieved.

In this embodiment, the first laser to the nth laser emitted by the first semiconductor laser chip to the nth semiconductor laser chip of the single tube are respectively collimated, then the first laser to the nth laser are spatially combined, then the first laser to the nth laser in the spatially combined laser are coupled into the optical fiber 120 by the focusing coupling mirror, and then reflected by the partial reflection film 121 on the input end surface of the optical fiber, and the partial reflection film 121 respectively partially reflects the first laser to the nth laser, so that phase interlocking of the kth semiconductor laser chip and the N-k +1 semiconductor laser chip is realized, and partial coherent combination is realized. When the partially reflective film layer 121 is a narrow-band partially reflective film, wavelength locking and spectrum narrowing are achieved while partially coherent beam combination is achieved. The beam quality of the combined laser is improved, and meanwhile, wavelength locking output can be realized.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.