Abstract

High power, broadly tunable visible and infrared sources based on optical parametric oscillators (OPOs) and difference frequency generation (DFG) are being developed for applications in areas such as remote sensing, lidar and spectroscopy. In may cases these sources are based on critically phase-matched (CPM) processes in highly biréfringent materials such as ß-barium borate (BBO). OPO operating efficiencies, particularly in the high power regime, are limited by crystal acceptance angles and Poynting vector walkoff of e-polarised beams. Recent results^1,2 indicate that improved operating efficiencies can be achieved using noncollinear CPM configurations. Poynting vector walkoff compensation (PVWC) and increased pump crystal acceptance angle at the onset of tangential-phase-matching (TPM) have been proposed as possible mechanisms for the enhanced operation.

© 1998 IEEE