High-energy 2.8-μm Ultrashort Pulses Generation in an Er:ZBLAN Fiber Amplifier

Abstract Compact, high-energy ultrashort pulsed fiber lasers in the 2.8 μm wavelength have attracted extensive interest in many scientific and industrial applications. Here, we demonstrated the generation of μJ-level ultrashort pulses from a quasi-all-fiberized Er:ZBLAN amplifier employing a 2.8-μm frequency-shifted soliton as a seed laser. With backward pumping, the pulse energy was enhanced to 0.282 μJ when the average output power was amplified to 1.023 W. Mechanisms for the generation and amplification of ultrashort pulses were theoretically revealed by numerical simulation, and further cascaded indium fluoride (InF3) fiber to obtain a 4.26-μm redshift soliton numerically. This compact fiber amplification system consisting of frequency-shifted-based seed pulses and fluoride fiber amplifiers will be of practical interest in applications.