Implementation of electro-optic spectral shearing interferometry for ultrashort pulse characterization

Electro-optic spectral shearing interferometry is implemented for the highly sensitive characterization of ultrashort pulses from a free-running source. A simple phase-locked-loop clock recovery circuit is used to extract the high-frequency microwave clock signal to drive the phase modulator for spectral shearing. We demonstrate accurate full temporal characterization of 200-fs pulses from an optical parametric oscillator at 5-pW average power.