Semiconductor laser device with high-power and high-beam-quality lasers

Abstract

Disclosed is a semiconductor laser device with high-power and high-beam-quality lasers. An outer resonant cavity is constructed in the outer portion of a semiconductor booster element, and a collimation optical element, a spectral dispersion element and a coupling output mirror are sequentially arranged in the outer resonant cavity. The semiconductor booster element comprises a plurality of active gain areas which are linearly arranged in parallel, a coating with the high reflectivity on the laser wavelength is plated on one side of each active gain area, a coating with the high transmittance on the laser wavelength is plated on the other side of each active gain area, the collimation optical element is arranged behind the side, plated with high-transmittance coatings, of the semiconductor booster element, and the direction of a central optical axis coincides with the direction of the central optical axis of emitted light beams of the semiconductor optical booster element. The spectral dispersion element is placed behind the collimation optical element with a certain angle, and the coupling output mirror is arranged behind the spectral dispersion element in the beam propagation direction. According to the laser device, the mode of laser shock is improved, and the output power of the laser device is effectively improved on the premise of not affecting the laser beam quality.

Description

technical field [0001] The invention relates to a power expansion technology of an external cavity semiconductor laser, in particular to a semiconductor laser with high power and high beam quality laser. Background technique [0002] Due to its high brightness, good monochromaticity, good collimation and focusing performance, laser has been widely used in scientific research, military defense, industrial processing, astronomical observation and information dissemination and other fields. The beam quality of the laser is a parameter that describes the focusing and collimation capabilities of the laser during propagation. A laser with high beam quality will get a smaller spot after focusing and a smaller far-field divergence angle after collimation. Therefore, in practice In applications, lasers with high beam quality have always been the direction people are pursuing. However, as the output power of the laser increases, factors such as thermal effects will gradually be ampli...

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Problems solved by technology

However, as the output power of the laser increases, factors such as thermal effects will gradually be amplified, thereby affecting the beam quality of the laser. Therefore, the beam quality and power of the laser have always been in opposition to each other. When developing a laser, the pros and cons of practical applications must be weighed. A trade-off between these two parameters

[0003] Compared with other types of lasers (such as gas lasers and solid-state lasers), semiconductor lasers have higher electro-optical efficiency (no fiber coupling loss or secondary pump loss), low cost (no expensive high-power energy transmission fibers), etc. advantages, but its beam quality will seriously deteriorate with the increase of laser output power, how to effectively expand the output power of semiconductor lasers under the premise of maintaining beam quality has always been a research hotspot in this field

[0004] Semiconductor laser array (bar) technology is a very convenient semiconductor laser power expansion technology. Its principle is to arrange several semiconductor light-emitting units in parallel on the substrate so that the output power of the laser increases linearly with the number of light-emitting units. However, due to The near-field wavefront of the laser beam obtained by this method is divided, so the beam quality is very poor, and it cannot be effectively applied to technical fields such as fiber coupling, welding, and cutting that require high-beam quality lasers.

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