Gradient heating-temperature control method of end-pumped alkali vapor laser

Abstract

The invention discloses a gradient heating-temperature control method of an end-pumped alkali vapor laser. The method comprises the following steps of (1) dividing an alkali vapor pool into different areas along an optical axis direction; (2) setting corresponding working temperatures of various areas according to the actual condition; and (3) carrying out independent temperature control on various areas by using a plurality of independent temperature controllers, making the temperatures of the areas reach set parameters respectively and achieving gradient heating and temperature control on the vapor pool. According to the gradient heating-temperature control method of the end-pumped alkali vapor laser, non-uniform distribution of the density of an alkali vapor medium in the closed vapor pool can be achieved, the phenomenon that most of pump energy is absorbed by a laser medium close to an input end window in the vapor pool can be avoided, the probability of damage to the end window of the vapor pool caused by chemical reaction of a working material and a buffer gas can be reduced, uniform absorption of the pump energy by a gain medium in the optical axis direction of the vapor pool can be achieved, and improvement of the finally output DPAL beam quality is facilitated.

Description

technical field [0001] The invention belongs to the field of heating-temperature control of an alkali metal vapor pool, and relates to a gradient heating-temperature control method of an end-pumped alkali metal vapor laser. Background technique [0002] Diode Pumped Alkali Vapor Laser (DPAL) is a new type of high-efficiency laser that uses a semiconductor laser (LD) to excite an alkali metal laser medium in a gas state. It combines the main advantages of gas lasers and semiconductor laser pumped solid-state lasers, while overcoming their main shortcomings, with high Stokes efficiency, good beam quality, excellent thermal management performance, narrow line width, compact laser structure, etc. advantage. DPAL has shown obvious technical advantages and application potential in the field of high-power laser applications, and is rapidly becoming one of the next-generation practical high-power new laser sources. [0003] As the gain medium of DPAL, alkali metal vapor can be obt...

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Problems solved by technology

This brings about two problems: on the one hand, the laser medium in the area near the input window will generate a lot of heat when absorbing the pump energy, which will cause the local temperature in a certain area of ​​​​the vapor pool to be higher than the external temperature. The operating temperature set by the control system will affect the output beam quality and light-to-light conversion efficiency of DPAL; on the other hand, when high pump power density is injected, for the vapor state laser medium near the input window, The electrons at the upper energy level of the laser at high temperature will jump to the excited state of a higher energy level through the collision energy pooling effect (Energy Pooling), and chemically react with the hydrocarbon buffer gas in the vapor pool, resulting in chemical deposition pollution, that is, "laser "snow" phenomenon, which affects the continuous high-power operation capability of the alkali metal laser, and even directly causes damage to the end window of the vapor pool, making the laser unable to work normally

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