Abstract

Recently, there has been a growing interest in the development of ultra-low-jitter optical pulse sources for use in analog-to-digital conversion of wide-band RF signals,¹⁻⁵ as well as in novel optical communications schemes. To date, the lowest reported values of jitter, 5-fs to 15-fs (10 Hz-1 MHz), have come from groups utilizing mode- locked fiber lasers,^2,3 while it has been assumed that the jitter in modelocked semiconductor sources was larger due to the very short upper- state lifetime (10⁷ times shorter than that of Erbium). However, it has been determined that, to first order, the lifetime does not play a role in the jitter and that the jitter is determined by the cavity loss and cavity Q. Here we show the major influence that the laser resonator has on the phase- noise, and hence timing jitter, and for similar cavity Q show the connection of the timing jitter between the semiconductor modelocked laser and that of modelocked fiber lasers.

© 2002 Optical Society of America