Comparison of Raman and degenerated optical parametric oscillators for a high-energy and high-repetition-rate eye-safe laser
A high-pressure laminar flow, methane-filled Raman cell has been used for nonlinear conversion of a 100-Hz Nd-YAG laser operating at 1.06 micrometers to eye-safe radiation at 1.54 (mu) M. The laminar flow is obtained between two-concentric cylinders rotating at the same angular velocity. Using a noncritically phase-matched optical parametric oscillator, the same laser source was also converted to 1.57 micrometers eye- safe radiation. Pump recirculation was used in both cases. Good conversion efficiencies, almost independent of the pulse repetition rate, were obtained with both conversion techniques.