A Tm-Ho codoped fiber based 38 nm wideband wavelength tunable passively Q-switched Er-doped fiber laser

Exploiting a piece of 0.2 m long Tm-Ho codoped fiber as the saturable absorber, we demonstrate a wideband wavelength tunable passively Q-switched Er-doped fiber laser. The Tm-Ho codoped fiber has a wide absorption band around 1550 nm, promising wideband Q-switching of Er-doped fiber lasers. With a Fabry-Perot tunable filter, stable passive Q-switching is observed in a wide wavelength range from 1535 to 1573 nm. The repetition rate of the laser system is tunable with both the pump power and the lasing wavelength in the range between 0.5 and 50 kHz.