Abstract

Optical parametric chirped pulse amplification (OPCPA)^1,2 is an attractive short pulse amplification technology because of its simplicity, broad bandwidth and large gain. Pulses from a mode- locked oscillator can be amplified to mJ energies in a single pass of only 2 or 3 non-linear crystals. Furthermore, OPCPA does not intrinsically produce pre-pulses and does not require electrooptic switching to either select a single pulse from an oscillator pulse train prior to multipass amplification or to inject/eject a pulse from a regenerative amplifier. The major drawback of OPCPA, however, is pump conversion efficiency. The spatio-temporal evolution and relatively long pulse width of commercial Q-switched lasers limits conversion. The highest OPCPA extraction efficiency reported to date from a system pumped by a commercial Q-switched Nd:YAG laser is 6%.³ It is expensive and complicated to produce an ideal pump pulse with a top hat in spatial and temporal profile. On the other hand, pump to IR conversion efficiencies of >50% or 90% of the maximum theoretical quantum efficiency have been demonstrated from chirped-pulse, Ti:sapphire amplifiers pumped by commercial Nd:YAG lasers.⁴ We present here the first demonstration of simple hybrid chirped pulse amplification scheme which combines the best of both technologies.

© 2002 Optical Society of America