A 1625 nm Q‐Switched All‐Fiber Laser

A Q-switched all-fiber Er-doped laser operated at a wavelength up to 1625 nm is proposed and demonstrated. self-developed, element hybridization (Al, Ge, La, P, Er in the core, Si P cladding region) glass fiber with gain extended U-band employed as medium. The compact cavity contains Bragg grating which was manufactured by means of point-by-point femtosecond inscription technique. Stable pulse train successfully achieved using semiconductor saturable absorber mirror low pump threshold 29 mW. has maximum single energy 746 nJ minimum duration 26.8 μs. repetition rate can be gradually tuned from 6.47 11.87 kHz increasing power. In particular, long nm. This is, best our knowledge, longest for lasers this waveband.