Pulse compression for more efficient operation of solid-state laser amplifier chains

Abstract

We propose a pulse compression scheme which reduces the peak intensity while increasing the energy density achievable in a Nd:glass amplifier chain. Self‐focusing is the dominant effect responsible for limiting the power of a short‐pulse Nd:glass amplifier chain, and the reduction of the intensity (through this compression scheme) greatly reduces these problems. We recommend injecting a lower‐intensity and longer‐duration pulse into the chain. Under some circumstances, the glass nonlinearity will impress upon the pulse a chirp suitable for efficient subsequent temporal compression, and this may result in higher effective peak power operation. If a 1‐nsec (full 1/e duration) temporally Gaussian pulse with a chain‐averaged peak intensity of 2 GW/cm² propagates 2 m in a Nd:glass laser chain, we calculate that the pulse could be subsequently compressed (by a series of Gires‐Tournois interferometers) to 125 psec with good stability against input pulse amplitude noise. Such short pulses are of major interest for laser fusion.