Intracavity second harmonic generation of 0.532 μm in bulk periodically poled lithium niobate

Abstract

We report on CW quasi-phase-matched intracavity frequency doubling of a 1.064 μm Nd:YAG laser. The 5 mm long and 0.2 mm thick crystal of periodically poled LiNbO3 was Brewster angle cut. When located intracavity, it presented an effective nonlinear coefficient d33 of 4.5 pm/V and an estimated loss per pass less than 10%. The observed temperature bandwidth of ∼ 5 K compares favourably with the theoretical value and indicates that the whole length of the crystal was contributing to the frequency doubling process.