Mid-infrared all-fiber laser oscillator based on conical double-cladding Raman gain fiber and method for generating mid-infrared laser

Abstract

The invention discloses a mid-infrared all-fiber laser oscillator device based on a conical double-clad Raman gain fiber and a method for generating mid-infrared laser. Laser output of a plurality ofhigh-power mid-infrared quantum cascade lasers enters an optical fiber beam combiner through respective multimode tail fibers to be used as a pump; a section of mid-infrared single-mode optical fiberwith a conical double-cladding structure is used as a Raman gain medium; a pair of mid-infrared Bragg fiber gratings are inscribed at two ends of the conical double-cladding Raman gain fiber to form alaser resonant cavity; and a cladding mode stripper with an optical fiber structure is welded at the output end of the gain fiber, so that mid-infrared near-single transverse mode laser output is realized. The conical double-cladding Raman gain fiber adopted by the invention can effectively improve the absorption efficiency of pump light, improve the conversion efficiency from low-brightness pumplight to high-brightness laser output, and improve the beam quality of laser output, and mid-infrared hundred-watt-level high-power near-single-mode laser output of 4 microns or above can be realized.

Description

technical field [0001] The invention relates to a mid-infrared all-fiber laser oscillator device, in particular to a mid-infrared all-fiber laser oscillator based on a tapered double-clad Raman gain fiber and a method for generating mid-infrared laser. Background technique [0002] The mid-infrared 3-14 micron band has important practical value. The fingerprint fundamental vibration absorption lines of life-related carbon, hydrogen, oxygen, nitrogen-containing gas molecules and volatile organic compounds all fall in this band, so the mid-infrared Spectral technology can perform simultaneous online, fast and accurate qualitative and quantitative analysis of multi-component trace gases, which is of great importance in many application scenarios such as military defense, environmental monitoring, industrial production process monitoring, toxic and explosive gas detection, and disease diagnosis. need. [0003] Mid-infrared laser sources with high power, high brightness, and nea...

AI Technical Summary

Problems solved by technology

However, realizing high-power continuous laser output with high beam quality and a power level of 100 watts is the ceiling that the current mid-infrared quantum cascade laser technology cannot reach; as its laser output power exceeds 10 watts, the beam quality of quantum cascade lasers will decrease. At the same time, the thermal management of the mid-infrared semiconductor laser light source under high power conditions is also a great technical challenge

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