Abstract

Amplification of femtosecond pulses to microjoule energies using pulse-pumped dye amplifiers is limited to about 10 kHz by the repetition rate of the pump lasers (typically copper vapor [1] or frequency-doubled Nd:YAG regenerative amplifiers[2]). In this paper I demonstrate that the superior energy storage of Ti:sapphire makes it possible to amplify femtosecond pulses to the microjoule level in a cw-pumped regenerative amplifier. The gain storage time of Ti:sapphire is 3 µs, which makes it possible to efficiently extract the energy stored by the pump at repetition rates of greater than 250 kHz (i.e. approximately the inverse lifetime). Q-switching, injection, and cavity dumping of the amplifier are done acousto-optically, thereby circumventing previous limitations due to electro-optic switching [5].

© 1992 Optical Society of America