Passively mode-locked miniature Nd:YVO/sub 4/ lasers with up to 59-GHz repetition rates

Summary form only given.We demonstrate passively mode-locked Nd:YVO/sub 4/ lasers with pulse repetition rates ranging from 30 GHz up to 59 GHz using semiconductor saturable absorber mirrors. To our knowledge, these are the highest repetition rates ever obtained from a mode-locked solid-state laser. Previously, the maximum repetition rates of a passively mode-locked solid-state lasers was 2.7 GHz with a Cr:YAG laser and 2 GHz with a Ti:Sapphire laser. More recently, we have demonstrated 13 GHz and 29 GHz with a Nd:vanadate laser. The limited gain bandwidth of the Nd:vanadate laser results in picosecond pulses which set an upper limit on the pulse repetition rate. At these extremely high repetition rates the pulses begin to overlap. Our approach to obtain high repetition rates is to passively mode-lock Nd:vanadate lasers, which operate at their fundamental repetition rate (i.e., with only one pulse circulating in the cavity). The main challenge for passive mode locking solid-state lasers at high repetition rates is to avoid Q-switching instabilities. This quantitative understanding enabled us to explore the limits of passively mode-locked Nd:YVO/sub 4/ lasers with multi-GHz pulse repetition rates.