Intracavity frequency doubling of a Nd:YAG laser with an organic nonlinear optical crystal

We have demonstrated intracavity second-harmonic generation of green 532 nm light in a quasi-cw 1064 nm Nd laser using organic nonlinear optical crystals of 4-(N,N-dimethylamino)-3-acetamidonitrobenzene (DAN) immersed in index matching fluid contained in an antireflection-coated cuvette. This technique permits crystals to be used directly from solution growth without polishing or antireflection coating them. Up to 0.56 mW peak power of 532 nm light was generated from 2.3 W of intracavity 1064 nm peak power in 100 μs pulses. We also report preliminary results on true cw intracavity harmonic generation with antireflection-coated DAN crystals.