Single crystal planar waveguide of mNA(meta-Nitroaniline) which has a large nonlinear optical coefficient was fabricated by using modified Bridgeman method.
Optimal conditions for growing the single domain crystal film of high optical quality are investigated. The close contact between a spacer and the superstrate of waveguide was turned out to be the crucial factor for controlling the single domain seed. Using a Y-type spacer and a specially designed contact technique, single domain crystal film was obtained. It was also proved that the improper conditions of pulling rate, spacer thickness, and hot zone temperature resulted in generation of defects such as voids or cracks.
Second harmonic generation was carried out using two coupling methods, a grating coupling and a modified end-fire coupling. The modified end-fire couping allowed second harmonics to be generator from Nd:YAG laser with the conversion efficiency of ∼0.01%.
