Generation of High-Power Mid and Long Wave Supercontinuum Laser in a Large-Mode-Area Fluorotellurite-Chalcogenide Fiber Cascade System

In this letter, we report a high-power broadband flat supercontinuum laser system based on a large-mode-area (LMA) low-loss fluorotellurite fiber cascade with an LMA chalcogenide fiber.To effectively expand the coverage of the mid-infrared supercontinuum spectrum and enhance its flatness, a novel femtosecond Raman soliton laser with high peak power is used as the pump source.When pumping the fluorotellurite fiber, a supercontinuum extended to 4.2 m can be obtained, with an output power of 8.12 W. Subsequently, we further pumped the LMA AsS fiber.At the maximum input power, the output power of the supercontinuum can reach 2.6 W, with the spectral edge extending to 5.7 m, a 10-dB bandwidth spanning 2-4.7 m, and favorable power stability retained.To the best of our knowledge, this is the first laser system that uses a fluorotellurite fiber as a transition fiber and further cascades the chalcogenide fiber to generate mid and long wave infrared supercontinuum, achieving the highest output power of mid-long-wave infrared supercontinuum laser generated in AsS fiber reported to date.