Novel OPO couples cavity mirrors directly onto uncoated crystal

A tunable, continuous wave (CW), doubly resonant optical parametric oscillator (OPO) uses index-matching liquid to couple the cavity mirrors directly onto a lithium triborate (LBO) crystal, eliminating the need for dielectric coatings on the crystal itself. The liquid is a low-absorption, siloxane polyether (Cargille Laboratories, Cedar Grove, NJ) applied between the mirrors and the LBO crystal. The mirror coatings are designed to provide transmission greater than 80% at the pum¥wavelength and reflectivities of more than 99.7% for the signal and idler wavelengths.

Solid-state ultraviolet laser on display at Laser 95