Self-starting passive harmonic mode-locked femtosecond Yb3+-doped fiber laser at 1030 nm

We demonstrate, for the first time to our knowledge, a self-starting passive harmonic mode-locked femtosecond Yb3+-doped fiber laser with a scalable repetition rate of up to 585 MHz and >45 dB of supermode suppression. Pulse-to-pulse jitter of approximately 14 ps is measured by optical cross correlation at the ninth harmonic, and radiofrequency (RF) spectrum measurements show that certain correlations exist between pulses in harmonic mode. Our results suggest that one of the proposed passive harmonic mode-locking mechanisms may be dominant for this laser.