PHASE-MATCHED OPTICAL 2ND-HARMONIC GENERATION IN THE ORGANIC-CRYSTAL MBA-NP, (-)2-(ALPHA-METHYLBENZYLAMINO)-5-NITROPYRIDINE

Large (5 multiplied by 3 multiplied by 3 cm**3) crystals of the organic nonlinear optical material MBA-NP have been prepared by growth from solution, in an optically and structurally highly perfect state. Oriented cut and polished specimens were examined by the Maker fringe technique at a wavelength of 1. 064 mu m. Analysis of the data yielded d//2//2 as 69 multiplied by d//1//1 quartz with a corresponding coherence length of 2 mu m. A large rotation of the X and Z dielectric axes with wavelength (30 degree over 200 nm) was observed. Type I phase-matched second-harmonic generation (SHG) was recorded for the 1. 064 mu m dielectric axis set and a (010) faced crystal, phase matched SHG was observed for rotation about X to an angle of incidence of 45 degree . This angle is very sensitive to the correct alignment of dielectric axes and the effect of its misalignment was investigated.