Phase modulation of a picosecond optical parametric oscillator

The method of dynamic interferometry was used to demonstrate for the first time that radiation from a superradiant optical parametric oscillator, utilizing an LiNbO₃ crystal pumped by the second harmonic of a picosecond YAG:Nd³⁺ laser, exhibited both fast random phase modulation as well as slow square-law modulation. The passage of radiation from an optical parametric oscillator through a system with an anomalous dispersion based on a diffraction grating resulted in reduction in the pulse duration by a factor of 5.