Second-order interferometric autocorrelation for measuring group velocity dispersion and pulse broadening of femtosecond pulses.

Abstract

Femtosecond pulse broadening and group velocity dispersion (GVD) were measured using a second-order interferometric autocorrelation technique. Two reference laser pulses of 36fs and 55fs were generated first in a Ti:sapphire oscillator and then passed through the optical elements of Ti:sapphire crystal and BK7 and fused silica glasses. For rectangular Ti:sapphire crystal and BK7 and fused silica slabs, material dispersion, and for fused silica prisms, material as well as angular dispersions were systematically measured. The experimental results were then compared with theoretical models, showing excellent agreement. The result of this work shows that one can rely very well on theoretical expressions to calculate the GVD of materials mentioned in this work and femtosecond pulse broadening.