External cavity feedback spectrum combining device capable of adjusting output beam spectral width

Abstract

The invention provides an external cavity feedback spectrum combining device capable of adjusting output beam spectral width. The device includes a concave spherical mirror capable of rotating about the spherical center and a convex spherical mirror fixed in position, wherein the concave spherical mirror is used for reflecting and gathering incident parallel beams to the convex spherical mirror, the convex spherical mirror is used for reflecting and collimating the incident parallel beams reflected and gathered by the concave spherical mirror to form parallel light output, focal points of theconcave spherical mirror and the convex spherical mirror coincide, the curvature radius R of the concave spherical mirror is larger than the curvature radius r of the convex spherical mirror, and a spherical center interval of the concave spherical mirror and the convex spherical mirror is (R-r) / 2. The device is advantaged in that a limitation that a conventional lens and prism shaping have a certain divergence effect on different frequency beams is solved.

Description

technical field [0001] The invention relates to the technical field of semiconductor lasers, in particular to an external cavity feedback spectrum beam combiner capable of adjusting the spectral width of an output beam. Background technique [0002] High-power semiconductor lasers have the advantages of light weight, maintenance-free and high reliability, and have broad application prospects in the fields of intelligent equipment manufacturing, medical treatment and communication. However, due to the special principle and structure of semiconductor lasers, there is a trade-off between output power and beam quality, that is, the beam quality will deteriorate while pursuing high power. [0003] The key technology to solve this problem is to package semiconductor lasers into an array or stack structure, and then use spectral beam combining technology to achieve single beam output. Spectrum beam combining technology often uses a grating as a dispersive element, and the oscillat...

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Problems solved by technology

[0004] At present, the methods of compressing the spectrum to synthesize the beam spectral width mainly include: 1. Increase the focal length of the conversion lens, but this method will increase the transmission path of the beam in the grating external cavity, resulting in easy beam crosstalk between sub-units; 2. Increase the grating line Density, however, the grating is the main dispersion element of the spectrum beam combining system, changing its linear density will affect its diffraction efficiency, and the linear density is limited by the laser wavelength; 3. Reduce the distance between subunits, but due to the limitation of semiconductor laser packaging technology, Limited ability to compress spectral width by reducing subunit spacing

In the case of limited packaging technology, an external optical system is used to compress the beam spacing. The existing technology uses 4f optical imaging systems and prisms to compress the beam spacing, but the lenses and prisms in the optical system have dispersion effects on beams with different wavelengths. , it is easy to cause the beam divergence angle to increase and reduce the beam combining efficiency

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