Recent Advances in 3.5 μm Erbium-Doped Mid-Infrared Fiber Lasers.

The performance of mid-infrared Er3+-doped fiber lasers has dramatically improved in the last few years. In this paper, we present an overview of the progress in 3.5 \mu \textm fiber lasers based on the dual-wavelength pumping approach. The cross section of the excited state absorption transition used by the 1973  \textnm second pump is found experimentally. A numerical simulation of the expected Q-switched behavior of this fiber laser is presented. This shows that increasing the power of the 977 \textnm pump is important to achieve high-peak power pulses. [ABSTRACT FROM PUBLISHER]