Measurement of femtosecond optical pulses using time-resolved optical gating

Abstract

Summary form only given. Time-resolved optical gating (TROG) is a recently-proposed technique which is a direct analogue of frequency-resolved optical gating (FROG) and is capable of determining the complex amplitude profile of an ultrashort optical pulse without any ambiguities. TROG traces can be classified as sonograms and can be measured using two geometries, frequency-domain phase measurement (FDPM) or dispersive-propagation (DP). The DP-TROG measurement yields an auto-sonogram of the pulse by recording a series of second-order autocorrelation profiles of the pulse after it has passed though a system of variable group-velocity dispersion. The only experimental implementation of this technique demonstrated so far was applied to picosecond pulses and relied on difficult and error-prone dispersion calculations which reduced its attractiveness as a practical pulse characterization technique, particular when applied to femtosecond pulses. We describe a simple and easy-to-calibrate procedure for DP-TROG measurement of pulses from a Ti:sapphire laser oscillator.