Numerical analysis for single-frequency nanosecond optical parametric oscillators and optical parametric amplifiers

We numerically analyze single-frequency nanosecond optical parametric oscillators and amplifiers. It shows that a single-frequency optical parametric oscillator requires a single-frequency pump wave and a seed source for injection locking. The power of the injection seed should be increased dramatically to maintain single-frequency output as pump energy increasing. The results numerically verify that high energy and single-frequency output waves can hardly be reached simultaneously by optical parametric oscillators. Multistage optical parametric amplifiers are helpful to meet the shortcoming of optical parametric oscillators. During the amplification, the pump energy should match the signal energy in optical parametric amplifiers to obtain high conversion efficiency.