Tunable medium-infrared optical fiber mixed gas cascaded Raman laser

Abstract

The invention discloses a tunable medium-infrared optical fiber mixed gas cascaded Raman laser, which comprises a near-infrared tunable laser pumping source, an input coupling module, an input gas cavity, a hollow-core optical fiber, an output gas cavity, an output guiding element and a coupling output mirror which are sequentially arranged along an optical path, and further comprises a feedback system, wherein the hollow-core optical fiber is filled with two mixed Raman gain gases which is used for making pump light undergo stimulated Raman scattering to generate first-stage Raman laser and making the first-stage Raman laser undergo stimulated Raman scattering to generate second-stage Raman laser in medium-infrared band; and the feedback system is used for guiding the first-stage Raman laser and the second-stage Raman laser in medium-infrared band which are transmitted by the coupling output mirror into an input window. The tunable medium-infrared optical fiber mixed gas cascaded Raman laser has the advantages of narrow line width, tunable property, low pump threshold, high conversion efficiency and the like.

Description

technical field [0001] The invention relates to the technical field of laser generating equipment, in particular to a tunable mid-infrared optical fiber mixed gas cascaded Raman laser. Background technique [0002] The mid-infrared band is located in the atmospheric window and is widely used in remote sensing detection, lidar, communication, and military fields. At present, the lasers that realize output in the mid-infrared band mainly include quantum cascade lasers, electronic vibration solid-state lasers, optical parametric oscillators, and fiber lasers. Among them, quantum cascade lasers generate more heat during continuous operation, and their excited regions are large, making it difficult to achieve high-power single-mode output; electronic vibration solid-state lasers can achieve 2-5 μm high-efficiency output, but the thermal lens effect limits its Increase in power; optical parametric oscillators can achieve tunable mid-infrared output at a power level of several wat...

AI Technical Summary

Problems solved by technology

However, when gas stimulated Raman scattering is realized in free space, the effective distance is limited by the Rayleigh length, the pumping threshold is high, and many competing Raman lines will be generated.

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