An Yb:glass regenerative amplifier directly side pumped by four 20-W diodes is demonstrated. By use of a novel pumping scheme and introduction of cylindrical optics into the cavity, a free-running average output power as great as 4 W with a TEM<sub>00</sub> -like mode was achieved from the bare cavity, with a 0.56 pump duty cycle. When the regenerative amplifier injected, 1-mJ 200-fs FWHM pulses were obtained following compression by use of 2-ms pump pulses and up to a 150-Hz repetition rate.
© 1999 Optical Society of America
(140.3280) Lasers and laser optics : Laser amplifiers
(140.3480) Lasers and laser optics : Lasers, diode-pumped
(140.3580) Lasers and laser optics : Lasers, solid-state
(320.7090) Ultrafast optics : Ultrafast lasers
H. Liu, S. Biswal, *J. Paye, †J. Nees, G. Mourou, C. Hönninger‡, and U. Keller, "Directly diode-pumped millijoule subpicosecond Yb:glass regenerative amplifier," Opt. Lett. 24, 917-919 (1999)