INTRACAVITY SECOND-HARMONIC GENERATION USING A DEUTERATED ORGANIC IONIC-CRYSTAL

A large organic ionic crystal (10 x 28 x 15 mm3):4-nitrophenol sodium( :Na) salt dihydrate (NPNa) crystal, which had good optical, mechanical , and thermal properties, was grown for the second-harmonic generation (SHG) device. Its effective nonlinear constant was found to be 5.0 pm /V at 1064 nm. The Vickers hardness and thermal conductivity were abou t two times larger than those of molecular crystals. The SHG device ma de of DNPNa, in which the water of crystallization of NPNa was deutera ted, was used for the intracavity SHG of a diode-pumped cw Nd:YVO4 las er. High SHG power of 4.4 mW at 532 nm was obtained for the first time with an organic nonlinear material.