CN-115967014-B - Spectrum beam combining device of linear array semiconductor laser

Abstract

The invention discloses a spectrum beam combining device of a linear array semiconductor laser, which comprises a fast axis collimating mirror, a slow axis collimating mirror, a first cylindrical surface transmission lens and a diffraction grating which are sequentially arranged along an optical axis of the linear array semiconductor laser, wherein a second cylindrical surface transmission lens, a first concave mirror group and a second concave mirror group are sequentially arranged in a 0-order diffraction beam direction of the diffraction grating, a-1-order diffraction beam of the diffraction grating is used as output light, the first concave mirror group and the second concave mirror group respectively regulate angles according to a 'smile' effect of the linear array semiconductor laser, so that feedback light returns to a corresponding light-emitting unit of the linear array semiconductor laser to form effective feedback, and meanwhile, a curved surface of the first concave mirror group converges divergent beams in the fast axis direction along the fast axis direction of the linear array semiconductor laser, so that the beams are fed back to an original light-emitting unit, the feedback efficiency is improved, and the light-emitting unit achieves stable wavelength locking.

Inventors

• JIANG MENGHUA
• JIN ZHUANG
• LIU YOUQIANG
• QIN WENBIN
• CAO YINHUA
• WANG ZHIYONG

Assignees

• 北京工业大学

Dates

Publication Date

20260505

Application Date

20221226

Claims (6)

1. 1. A spectrum beam combining device of a linear array semiconductor laser is characterized by comprising the linear array semiconductor laser and a fast axis collimating lens, a slow axis collimating lens, a first cylindrical surface transmission lens and a diffraction grating which are sequentially arranged along an optical axis of the linear array semiconductor laser, wherein a second cylindrical surface transmission lens and a first concave surface reflecting mirror group are sequentially arranged in a 0-order diffraction beam direction of the diffraction grating, a second concave surface reflecting mirror group is arranged in a 1-order diffraction beam direction of the diffraction grating, and-1-order diffraction light of the diffraction grating is used as output light; The first concave reflector group and the second concave reflector group reflect diffraction beams incident on the first concave reflector group and the second concave reflector group and feed the diffraction beams back to the linear array semiconductor laser to form external cavity wavelength locking; The first concave reflecting mirror group and the second concave reflecting mirror group comprise two separated concave reflecting mirrors, the two separated concave reflecting mirrors are formed by separating a concave reflecting mirror from the center along the fast axis direction of the linear array semiconductor laser, the two separated concave reflecting mirrors respectively adjust angles according to the 'smile' effect of the linear array semiconductor laser, feedback light is returned to a corresponding light-emitting unit of the linear array semiconductor laser to form effective feedback, and meanwhile, the curved surface of the first concave reflecting mirror group converges divergent light beams along the fast axis direction of the linear array semiconductor laser, so that the light beams are returned to the original light-emitting unit.
2. 2. The spectral beam combining device of the linear array semiconductor laser according to claim 1, wherein the front cavity surface of the linear array semiconductor laser is plated with an antireflection film, and the transmittance is more than or equal to 99%.
3. 3. The spectral beam combining device of the linear array semiconductor laser device according to claim 1, wherein the fast axis collimating mirror is a cylindrical micro lens, the slow axis collimating mirror is a cylindrical micro lens array, and the light transmitting surfaces of the fast axis collimating mirror and the slow axis collimating mirror are plated with antireflection films, wherein the transmittance is more than or equal to 99%.
4. 4. The spectral beam combining apparatus of a linear array semiconductor laser of claim 1, wherein the diffraction grating is disposed at a Littrow angle with respect to the optical axis.
5. 5. The spectral beam combining device of the linear array semiconductor laser device according to claim 1, wherein the light transmission surfaces of the first cylindrical surface transmission lens and the second cylindrical surface transmission lens are plated with antireflection films, the transmittance is more than or equal to 99%, the focal lengths f of the first cylindrical surface transmission lens and the second cylindrical surface transmission lens are the same, a 4f far-focusing telescope system is formed, the first cylindrical surface transmission lens superimposes light beams emitted by all light emitting units on the linear array semiconductor laser device on a diffraction grating, and the second cylindrical surface transmission lens superimposes feedback light beams on the diffraction grating.
6. 6. The spectral beam combining device of the linear array semiconductor laser according to claim 1, wherein the first concave reflecting mirror group and the second concave reflecting mirror group are coated with a high reflection film, and the reflectivity is more than 99%.

Description

Spectrum beam combining device of linear array semiconductor laser Technical Field The invention relates to the technical field of semiconductor lasers, in particular to a spectrum beam combining device of a linear array semiconductor laser. Background The semiconductor laser has the advantages of high efficiency, small volume, long service life, rich wavelength, direct electric drive and the like, but is limited by the quality of light beams and the output power of a single light-emitting unit, and can only be used for pumping sources of other lasers and application fields with low requirements on the quality of light beams. Beam combining techniques are a common method of obtaining high power semiconductor lasers, and are generally classified into two major categories, coherent combining techniques and incoherent combining techniques. The coherent beam combining technology is a method for improving the brightness of an output beam by controlling the phase relation of each light-emitting unit to generate constructive interference by utilizing the coherence of laser. Although the coherent beam combining technology can effectively improve the beam quality of the semiconductor laser array, the method has high adjustment precision, is easily interfered by external environment, and is difficult to obtain high-power stable laser output. The spectrum beam combining technology in the incoherent beam combining technology avoids the defects and is relatively easy to realize, and is an effective method for improving the beam quality of the semiconductor laser array and improving the brightness. The spectrum beam combining technology utilizes a dispersion element to enable multiple paths of lasers with different wavelengths to be simultaneously and spatially overlapped in a near field and a far field, the lasers are synthesized into lasers output by a single aperture, the quality of the integrated beam after beam combination is close to that of a single light-emitting unit, and the output power is N times of that of the single light-emitting unit. The spectrum beam combining technology is divided into an open loop (without an output coupling mirror) structure and a closed loop (with an output coupling mirror) structure, and the main difference between the two structures is that the locking modes of the wavelengths of all the light emitting units are different. Compared with a closed-loop spectrum beam combination structure, the open-loop spectrum beam combination structure realizes feedback locking of the light emitting unit by utilizing 0-order diffraction beams of the grating, avoids dump and waste of the 0-order diffraction beams, and can well solve the problems of power loss, low beam combination efficiency and the like in a-1-order diffraction beam feedback cavity adopted by the closed-loop structure. Although the open-loop spectrum beam combination structure can better reduce power loss, due to lower 0-order diffraction efficiency of the grating, when the semiconductor array has obvious 'smile' effect, due to the influence of position deviation of light beams fed back to each light emitting unit, each light emitting unit is difficult to obtain enough feedback light beams at the same time, so that the problems of wavelength locking, poor output light beam quality and the like of only part of light emitting units can be realized, and even spectrum beam combination can not be realized in severe cases. The "smile" effect is an unavoidable inherent problem in the packaging process of the semiconductor array, and greatly limits the application of the open-loop spectrum beam combining structure. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a spectrum beam combining device of a linear array semiconductor laser, which can realize effective external cavity feedback and stable wavelength locking of an open-loop spectrum beam combining structure by utilizing the angle adjustment and convergence effect of a separation concave reflector, can overcome the adverse effect of simle effect on the open-loop spectrum beam combining wavelength locking, and provides a new scheme for realizing stable open-loop spectrum beam combining for a conventional commercial semiconductor laser array. The invention discloses a spectrum beam combining device of a linear array semiconductor laser, which comprises the linear array semiconductor laser and a fast axis collimating mirror, a slow axis collimating mirror, a first cylindrical surface transmission lens and a diffraction grating which are sequentially arranged along an optical axis of the linear array semiconductor laser, wherein a second cylindrical surface transmission lens and a first concave surface reflecting mirror group are sequentially arranged in a 0-order diffraction beam direction of the diffraction grating, a second concave surface reflecting mirror group is arranged in a 1-order diffraction beam direction of the diffraction grat