SPECTROSCOPIC AND NONLINEAR-OPTICAL APPLICATIONS OF A TUNABLE BETA-BARIUM BORATE OPTICAL PARAMETRIC OSCILLATOR

A pulsed beta-barium borate optical parametric oscillator (BBO OPO) se rves as the tunable source of coherent radiation for linear and nonlin ear-optical spectroscopic applications: photoacoustic absorption, opti cal double resonance, and coherent Raman spectroscopy. The BBO OPO is used spectroscopically either as a free-running broadband device with single multiplex detection or as a continuously tunable narrow-band de vice controlled by injection seeding. A single BBO crystal offers a wi de fundamental OPO tuning range (0.41-2.7 mum) that can be extended fu rther into the ultraviolet and infrared regions by additional nonlinea r-optical stages. Pumped at 355 ran by a single-mode Nd-YAG laser, the BBO OPO operates with high conversion efficiency and damage threshold and adequate beam quality for spectroscopic and nonlinear-optical pur poses.