It is shown that mode matching, aberration compensation, control of beam overlap, and feedback are critical issues in designing multipass amplifiers for ultrashort pulse amplification. We have developed a Ti:sapphire amplifier system capable of producing aberration-free millijoule-level 25-fs pulses at 1 kHz. This system has a unique five-mirror ring design, which is capable of compensating second-order aberrations, and the flexibility to mode match the input beam and the pump laser. A unique compressor, which is a part of the amplification system, was designed to eliminate feedback.
© 1998 Optical Society of America
(140.0140) Lasers and laser optics : Lasers and laser optics
(140.3280) Lasers and laser optics : Laser amplifiers
(140.3590) Lasers and laser optics : Lasers, titanium
(140.7090) Lasers and laser optics : Ultrafast lasers
Ming Li and George N. Gibson, "Flexible aberration-free multipass amplifier and compressor for ultrashort-pulse amplification," J. Opt. Soc. Am. B 15, 2404-2409 (1998)