Vol. 28, Issue 2, pp. 115-126

Abstract

We compare two types of optical parametric oscillators (OPO’s) with LBO and KTP crystals, pumped with a frequency doubled Q-switched Nd:YAG laser. The threshold pump power density near degeneracy was found to be 29 MW/cm² for the pulsed doubly resonant oscillator PRO) with LBO, and 5.7 MW/cm² for the DRO with KTP. The DRO was continuously tuned in the near infrared by rotation of LBO and KTP crystals. The full width at half-maximum (FWHM) linewidth of the signal radiation emitted by DRO-LBO at 998 nm was 10 nm, and 0.65 nm for DRO-KTP at 1052.6 nm.