Determination of pulse width and estimation of pulse-to-pulse jitter of femtosecond fiber laser pulses using optical autocorrelation and cross correlation techniques

The pulse width and pulse-to-pulse jitter of a mode-locked Imra Femtolite 780 nm-wavelength fiber laser was obtained using an optical autocorrelator and cross correlator. The autocorrelation and cross correlation were accomplished via second harmonic generation using a beta-barium borate (BBO) crystal in a noncollinear phase matching condition. Results for type I and type II phase-matching are presented. Type II results showed slight broadening effects on the correlation signal which is attributed to the birefringent properties of the crystal. The results demonstrate capabilities to perform modest optical autocorrelation and cross correlation measurements to evaluate ultrafast laser timing jitter characteristics without having to purchase expensive optical autocorrelators.