Ultrabroadband wavelength tuning from 400 nm to 1700 nm with near NCPM OPO and frequency doubling

Abstract

ABSTRACT Based on near-NCPM (Non Critical Phase Matching) design, type I temperature phase ma tching of MgO doped LiNbO 3 OPO (Optic Parametric Oscillation) with selected cutting angle at 82 degree. Replacing NCPM with near-NCPM to limit the operation temperature range to a relative low level, a temperature tuned OPO pumped by 532 nm is developed and 800-1700 nm tunable signal lights are achieved. Output pulse energy is higher than 5mJ by a pumping laser of 58 mJ, 532 nm and 6 ns. With frequency doubling of OPO light throug h a 24.5 degree cut BBO crystal, 2 mJ, 400-800 nm output is obtained by a 19 .8-29.2 degree rotating accordingly. The threshold of pump peak intensity for OPO is 57.3 MW/cm 2 . On the position of two times of threshold ener gy, SRO conversion effi ciency is over 11%. Keywords : OPO, NCPM, temperature tuned, LiNbO 3 , BBO. 1. INTRODUCTION NCPM (Non Critical Phase Matching) is frequently used in MgO:LiNbO 3 crystal. On the condition of NCPM ( T =90e ), temperature tuned Mg:LiNbO