CZOCHRALSKI CRYSTAL GROWTH PROCESS FOR ORGANIC NONLINEAR CRYSTALS

ALTHOUGH SEVERAL ORGANIC NONLINEAR SINGLE CRYSTALS HAVE BEEN REPORTED TO HAVE EXCEPTIONALLY HIGH FIGURES OF MERIT COMPARED WITH THE BEST INORGANIC CRYSTALS AVAILABLE, ORGANIC NONLINEAR CRYSTALS ARE NOT NOW BEING USED IN INDUSTRIAL, SCIENTIFIC, DEFENSE, AND AEROSPACE LASER SYSTEMS. THIS IS ATTRIBUTED PRINCIPALLY TO THE LACK OF A SUPPLY OF HIGH QUALITY SINGLE CRYSTALS OF A LARGE ENOUGH SIZE TO BE USEFUL. THE TECHNOLOGY FOR THE GROWTH, FABRICATION, AND POLISHING OF ORGANIC NONLINEAR CRYSTALS IS NOT NOW AVAILABLE. THE CRYSTAL GROWTH TECHNIQUES REPORTED IN THE LITERATURE FOR ORGANIC NONLINEAR CRYSTALS HAVE BEEN SOLUTION AND BRIDGMAN; AND CRYSTAL SIZES FOR COMPLEX COMPOUNDS HAVE BEEN OF THE ORDER OF A FEW MM OR LESS. RESEARCHERS ARE DEVELOPING A CZOCHRALSKI CRYSTAL GROWTH PROCESS CAPABLE OF PRODUCING LARGE (2 TO 3 CM) CRYSTALS OF HIGH PERFECTION; DEVELOPING METHODS FOR FABRICATING AND POLISHING SUCH CRYSTALS; AND CHARACTERIZING THEM WITH RESPECT TO CRYSTAL PERFECTION, OPTICAL ABSORPTION COEFFICIENTS, LASER DAMAGE, FREQUENCY CONVERSION EFFICIENCY, AND ELECTRO-OPTIC PROPERTIES. MMONS (3-METHYL-4-METHOXY-4'-NITROSTILBENE) WHICH HAS BEEN REPORTED TO HAVE ONE OF THE LARGEST NONLINEAR FIGURES OF MERIT, IS BEING USED AS A MODEL CRYSTAWL AND ALL WORK IS BEING CARRIED OUT WITH THIS CRYSTAL. HOWEVER, THE GROWTH PROCESS AS WELL AS FABRICATION TECHNIQUES THAT ARE DEVELOPED ARE APPLICABLE TO A WIDE RANGE OF ORGANIC NONLINEAR CRYSTALS.