Time- and Spectral-Domain Dynamics of 2-μm Pulses in the Holmium-Doped Fiber Amplifier

Ultrafast fiber lasers operating in the spectral range of 2000–2200 nm have attracted attention due to a number of their possible applications, such as perspective communication systems, material processing, supercontinuum generation, gas sensing, medicine etc [1]. It should be noted that for the most of applications, the output energy of the pulses of such lasers is not enough. Therefore, the goal of ultrashort pulses amplifying has arisen. Moreover spectral and temporal dynamics of ultrashort pulses in holmium-doped fiber amplifier [2] are interesting for supercontinuum generation in silica-based optical fibers. But in the last several years just a few works, dedicated to this problem [3, 4] were demonstrated. Thus, in this work, we demonstrate experimental investigation of time- and spectral-domain dynamics of 2-μm ultrashort pulses depending on input pulse parameters, length of the gain medium and gain coefficient.