Characterization and control of pulse shapes in a doubly resonant synchronously pumped optical parametric oscillator.

The intracavity signal and idler pulses of a low-loss synchronously pumped doubly resonant optical parametric oscillator were characterized experimentally and simulated numerically versus cavity-length detuning. At operation several hundreds of times above threshold, the detunings that maximize the intracavity average power do not necessarily maximize the temporal overlap of the signal and idler pulses, as is desirable for devices making use of intracavity mixing. Independent control of the signal and idler cavity lengths allowed control of the widths and temporal positioning of the pulses. Numerical studies were performed exploring the intracavity power and temporal overlap of the signal and idler pulses under various group-velocity-mismatch conditions. There was good agreement between the experimental and numerical simulation results.