GROWTH OF KTP CRYSTALS FOR NON-LINEAR OPTICAL APPLICATIONS

THE PROPOSED PROGRAM IS TO SHOW FEASIBILITY OF GROWING KTIOPO(4) CRYSTALS FROM FLUX USING THE HEAT EXCHANGER METHOD (HEM[TM]). THE NON-LINEAR OPTICAL COEFFICIENTS OF KTP ARE COMPARABLE TO BA(2)NANB(5)O(15) (BSN), AN OUTSTANDING MATERIAL FOR SECOND HARMONIC GENERATION OF 0.53 UM RADIATION FROM 1.06 MICROMETER LASER RADIATION. SMALL KTP CRYSTALS OF UP TO 125 MM(3) HAVE BEEN GROWN BY THE HYDROTHERMAL TECHNIQUE; FOR LARGER SIZES, NEW COLD WALL AUTOCLAVES NEED TO BE DESIGNED AND FABRICATED. THE MAIN PROBLEM ENCOUNTERED WITH KTP GROWTH FROM FLUX SO FAR HAS BEEN SPONTANEOUS NUCLEATION WHICH HAS PREVENTED GROWTH OF LARGE CRYSTALS. IN HEM THE TEMPERATURE GRADIENTS IN THE SOLID AND LIQUID CAN BE CONTROLLED SUCH THAT THE INITIAL NUCLEATION CAN BE CONTROLLED AND SPURIOUS NUCLEATION FROM THE CRUCIBLE WALLS CAN BE PREVENTED DURING THE CRYSTAL GROWTH CYCLE. INITIAL EXPERIMENTS WILL BE CARRIED OUT WITH UNSEEDED GROWTH, AND, THEREAFTER, IT IS INTENDED TO UTILIZE SEEDED GROWTH EXPERIMENTS. THE CRYSTALS WILL BE EXAMINED FOR MORPHOLOGY, FLUX INCLUSIONS, CLARITY, COMPOSITION AND OPTICAL TRANSMISSION.