Semiconductor laser MOPA (Master Oscillator Power Amplifier) system for pumping alkali metal vapor

Abstract

The invention discloses a semiconductor laser MOPA (Master Oscillator Power Amplifier) system for pumping alkali metal vapor, wherein a linewidth compression system, a beam shaping and coupling system, a seed optical system and a power amplification system are sequentially connected; a semiconductor laser linewidth compression system which consists of a fast-axis collimation lens, two plano-convex lenses and a holographic grating is used, meanwhile a buffer gas with a determinate optimized pressure value is charged into a master oscillation pool in the seed optical system and an amplification pool in the power amplification system so as to broaden an alkali metal atomic absorption line; and the linewidth of an LDA (Laser Diode Array) can be effectively compressed to the magnitude of that of the broadened alkali metal atomic absorption line so as to realize the matching of the linewidth of the LDA and the alkali metal atomic absorption line. Pump lights are allocated to two gain medium pools, i.e. the master oscillation pool and the amplification pool, according to the proportion of 1: 4, and as the structures of the two oscillation pools are completely identical, the quality of beams is ensured and meanwhile the heat quantity is dispersed, and the power can be amplified over multiple times.

Description

technical field [0001] The invention relates to an alkali metal vapor laser, in particular to a MOPA system for a semiconductor pumped alkali metal vapor laser. Background technique [0002] Diode-pumped alkali vopor lasers (DPALs) pumped by diode laser arrays (LDA) are new laser devices that have aroused great interest and achieved rapid development in recent years. They have the advantages of small quantum loss and high thermal management performance. , is expected to obtain efficient high-power near-infrared laser output with high beam quality. These near-infrared lasers have broad application prospects in laser cooling, directional energy transfer, material processing, etc. Rubidium (Rb) and Cesium (Cs) are widely used as gain media. On the one hand, in order to obtain a high-power alkali metal vapor laser, it is necessary to use a high-power semiconductor laser array as a pump source, but the line width of the pump source is generally 3-4 times larger than the line wi...

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Problems solved by technology

On the other hand, there are two kinds of pumping methods for DPALs: horizontal pumping and longitudinal pumping, and both have achieved good results in experiments. However, when these two methods are pumped at high power, there are radial temperature gradients. The thermal lens effect caused by the uneven refractive index of the gain medium leads to unstable output power and misalignment between the cavity mode and pump light, which affects the beam quality and limits the increase in laser power.

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