Advantages and Limits of Light Pulse Compression inside and outside the Laser Cavity

Abstract

Limits for the compression of frequency-modulated light pulses, the chirp of which is a result of non-linear optical interactions in non-resonant and resonant media, are dealt with. In extracavity pulse compressors with non-resonant, non-linear samples the minimum pulse duration decreases with increasing field strength of the input pulse, the maximum of which must be restricted to avoid high-order non-linear effects and optical damage. Compression down to about 5 fs seems to be possible. In intracavity pulse compression, successfully used for example in passively mode-locked lasers, the chirp is generated by quasi-resonant interaction between light pulses and saturable absorbers or depletable amplifiers. Here the minimum achievable pulse duration is limited mainly by the frequency-selective action of the quasi-resonant samples.