MIXED VAPOR GROWTH OF ORGANIC NONLINEAR OPTICAL MATERIALS

A METHOD OF GROWING SINGLE CRYSTALS AND CRYSTALLINE FILMS OFORGANIC MATERIALS FOR NONLINEAR OPTICAL APPLICATIONS IS INVESTIGATED. THIS METHOD, APPLIED TO THE GROWTH OF UREA CRYSTALS, USES GROWTH BY VAPOR TRANSPORT. CRYSTALS AREGROWN USING A MIXED VAPOR TRANSPORT METHOD COMBINING THE DESIRED MATERIAL WITH A COADSORBING VAPOR TO ATTEMPT TO OVERCOME THE HIGHLY ANISOTROPIC GROWTH RATES WITH CRYSTALLOGRAPHIC DIRECTION WHICH USUALLY PRODUCE CRYSTALS LARGE IN ONLY ONE DIRECTION. THE RESULTANT MODIFICATION OF GROWTH RATES CAN LEAD TO LARGER CRYSTALS OF ORGANIC MATERIAL, SUCH AS UREA, WITH LARGE NONLINEAR OPTICAL COEFFICIENTS.