Attosecond timing jitter pulse trains from semiconductor saturable absorber mode-locked Cr:LiSAF lasers

Abstract

The timing jitter of optical pulse trains from diode-pumped, semiconductor saturable absorber mode-locked femtosecond Cr:LiSAF lasers is characterized by a single-crystal balanced optical cross-correlator with an equivalent sensitivity in phase noise of -235 dBc/Hz. The RMS timing jitter is 30 attoseconds integrated from 10 kHz to 50 MHz, the Nyquist frequency of the 100 MHz repetition rate oscillator. The AM-to-PM conversion induced excess phase noise is calculated and compared with experiment. The self-steepening effect is proven to be the dominant AM-toPM coupling mechanism, whereas the semiconductor saturable absorber operation does not adversely affect timing jitter. The results show that ultrafast Cr: LiSAF lasers are promising compact and efficient ultralow-jitter sources.