A dual-wavelength cascaded pumped mid-infrared fiber laser

Abstract

The invention discloses a mid-infrared fiber laser with dual-wavelength cascade pumping, which includes a first semiconductor laser pump source, a second semiconductor laser pump source, a first dichroic mirror, a second dichromatic mirror, and a coupling lens. Vibration cavity; the first semiconductor laser pumping source and the second semiconductor laser pumping source generate two continuous pumping lights perpendicular to each other and with different wavelengths, which are synthesized into one beam by the first dichroic mirror, and then irradiated by the second dichroic mirror to The coupling lens is focused into the double-clad Ho3+ZBLAN fiber, and then oscillated in the resonant cavity composed of the double-clad Ho3+ZBLAN fiber and the mirror, and the laser is reflected by the mirror, and finally the second dichroic mirror output. The invention effectively solves the problem that it is difficult to generate laser light with a wavelength greater than 3 μm when pumped by a single wavelength pump source in the traditional mid-infrared fiber laser.

Description

technical field [0001] The invention relates to the technical field of mid-infrared lasers, in particular to a dual-wavelength cascaded pumped mid-infrared fiber laser. Background technique [0002] Mid-infrared laser light sources with high efficiency, small size, and wavelengths in the atmospheric window of the 3-5 μm region are widely used. For example, high-brightness mid-infrared laser light sources can not only be used in laser countermeasures in national defense, but also in advanced gas sensing technology and environmental monitoring. Among various methods of generating mid-infrared lasers, compared with optical parametric oscillators, optical parametric amplifiers, and quantum cascade lasers, fiber lasers have high brightness, high peak power, tunable, low laser threshold, and good output beam quality. , high conversion efficiency, high "surface area / volume" ratio, good flexibility and flexibility, and easy integration. Therefore, the development of high-efficiency...

AI Technical Summary

Problems solved by technology

The traditional mid-infrared fiber laser uses a single wavelength of pump light to pump the doped rare earth ion fluoride fiber, but the energy level of the rare earth ion energy level corresponding to the mid-infrared laser transition in the 3~5μm region is often lower energy. The lifetime of the upper energy level is higher than that of the upper energy level, and it is difficult to achieve particle population inversion at room temperature, so that the laser transition of the corresponding wavelength is self-terminated, and it is difficult to achieve laser output with a wavelength greater than 3 μm. At present, the longest at room temperature can only produce 3.005 laser with μm wavelength

At the same time, the laser source doped with rare earth ions has many unfavorable factors in the mid-infrared region, such as excited state absorption, energy transfer up-conversion and other transition processes, which increase the pumping threshold power of the laser, resulting in low laser efficiency and low output power. Greatly limits the practical application of mid-infrared fiber lasers

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