GROWTH OF LASER QUALITY AGGASE2

THE FEASIBILITY OF GROWING AND HEAT TREATING CRYSTALS OF AGGASE(2) TO YIELD OPTICAL ELEMENTS OF SUFFICIENT SIZE AND QUALITY AND SUITABLE FOR HIGH POWER NONLINEAR APPLICATIONS IS EXAMINED. THE HISTORY OF THE DEVELOPMENT OF THIS MATERIAL IS REVIEWED WHICH POINTS OUT THE MANY PROBLEMS ENCOUNTERED IN CRYSTAL GROWTH AND IN ELIMINATING UNDESIRABLE SCATTERING CENTERS IN THE GROWN CRYSTALS. BY ANALYZING THE COLLECTIVE EXPERIENCE GAINED FROM EARLIER STUDIES AND THE EXPERIENCE GAINED FROM CLOSELY RELATED MATERIALS SUCH AS AGGAS(2') A DETAILED PLAN OF ATTACK IS DEVELOPED. THE PROGRAM OBJECTIVES ARE: (1) TO PRODUCE AT LEAST ONE GOOD QUALITY 35MM DIAMETER BY 60MM LONG AGGASE(2) CRYSTAL BY A SEEDED BRIDGMAN METHOD, (2) TO DETERMINE PROCEDURES AND CONDITIONS TO ALLOW RECOVERY OF CRACK-FREE CRYSTALS ON A CONSISTENT BASIS, (3) TO DETERMINE HEAT TREATING CONDITIONS THAT YIELD CRYSTALS WITH ABSORPTION COEFFICIENTS LESS THAN 0.05CM-1, AND (4) TO EXAMINE SURFACE TREATMENTS TO INCREASE THE DAMAGE THRESHOLD TO GREATER THAN 50MW/CM" FOR Q-SWITCHED LASER PULSES. THE PEOPLE, FACILITIES, EXPERIENCE, CONTACTS, AND DESIRE AT CLEVELAND CRYSTALS ARE WELL SUITED TO MEET THESE PROGRAM OBJECTIVES.