Abstract

We describe an amplifier designed specifically for amplification of femtosecond optical pulses ¹,² at high repetition rate. A key problem in high repetition rate amplification is that the energy of the available pump pulses is only a few microjoules as compared to the hundreds of millijoules available for low repetition rate amplifiers². We resolve this problem, in part, by using multiple collinear passes to efficiently extract the pump pulse energy while also maintaining the transverse coherence and femtosecond duration of the amplified pulse. This combination of properties is important since it allows a variety of nonlinear optical experiments with femtosecond time resolution and good signal to noise ratio despite comparatively low amplified pulse energies. Previous work on high repetition rate amplifiers differs in that non-collinear geometries and only two passes were used. This produced lower net gains and the pulses were in the picosecond rather than femtosecond time domain³, ⁴.

© 1984 Optical Society of America