Generation of Tunable Pulses below 345 fs Using a Passively Mode-Locked Fiber Ring Laser with Bulk Components

A stable, passively mode-locked erbium-doped silica fiber ring resonator is fabricated to generate tunable optical pulses with durations of 270–345 fs in the 1.55 µ m band pumped by a 1.48 µ m semiconductor laser diode. The lasing wavelength is tuned continuously over a wavelength range of 60 nm from 1.532 to 1.594 µ m by rotating a bulk band-pass filter inserted in the resonator with a repetition rate of 45.4 MHz.