Abstract

Until recently the passively mode-locked dye laser has been the only reliable, widely used source of femtosecond optical pulses. Dramatic advances in all-optical modulation techniques and the appearance of novel broadband solid state gain media over the last few years opened up a new era in femtosecond pulse technology [1]. More than two decades after the first demonstration of a picosecond mode-locked laser, we have recently witnessed the emergence and evolution of a new generation of ultrashort-pulse lasers based exclusively on solid state components [2]. Intensive research efforts resulted in a good understanding of the basic physical processes dominating pulse formation in these novel sources [3], giving rise to a rapid progress of femtosecond solid state laser technology. This research culminated in the generation of sub-20 fs optical pulses directly from Ti:sapphire laser oscillators [4].

© 1994 Optical Society of America