Spatially resolved small-angle noncollinear interferometric autocorrelation of ultrashort pulses with microaxicon arrays

Small-angle, noncollinear, first- and second-order interferometric autocorr elation experiments with Ti:sapphire laser pulses of 9-80-fs duration have been performed with microaxicon arrays. Predictions of short-pulse spatial frequency effects were verified by comparison of interference patterns of s ingle elements and matrices. An angular spectrum of Gaussian-shaped axicons was analyzed on the basis of linear refraction. Experimental data indicate contributions to autocorrelation. by nonlinear refraction and travel-time differences. The influence of the spectral bandwidth was separated from the pulse-duration-dependent effects. Spatially resolved information about the coherence time was delivered by the multichannel structure. (C) 2001 Optic al Society of America.