Simple ultrashort light pulse chirp measurement device

Abstract

A simple device, Frequency Tracer (FT), for simultaneous measurement of ultrashort light pulse duration and chirp is presented. FT operation is based on the two-dimensional image analysis (time versus frequency) of the non-colinear secondharmonic autocorrelator beam, and FT enables one to evaluate the temporal phase variation over the femtosecond pulse duration. The spectral information of a fs pulse in FT originates from the angular divergence of a second-harmonic signal beam, and there is no need to use the spectral apparatus. Femtosecond pulses duration and chirp measurements of the Ti:sapphire laser system multi-pass amplifier (MPA) during adjustment of the compressor pair of gratings were made.