Self-starting passively mode-locked chirped-pulse fiber laser.

We present a self-starting passively mode-locked fiber laser operating in the chirped-pulse regime for the first time. A chirped fiber Bragg grating in the cavity provides positive dispersion with negligible nonlinearity. The laser generates positively-chirped pulses with a pulse duration of 22 ps at a repetition rate of 44 MHz, which are compressible down to 1.5 ps. We believe that the presented approach reveals a pulse energy scaling potential of mode-locked fiber lasers as nonlinear effects are significantly diminished compared the other known operation regimes.