GROWTH OF TITANIUM DOPED LANTHANUM MAGNESIUM HEXAALUMINATE (TI:LMAO) FOR TUNABLE SOLID STATE LASER APPLICATIONS

THE FIRST TITANIUM (TI) DOPED LASER, TI:A1203, WAS DIS- COVERED IN 1982 SINCE THAT TIME, TI HAS BEEN OF INTEREST AS A DOPANT IN VARIOUS LASER HOSTS FOR TUNABLE SOLID-STATE LASER APPLICA- TIONS. RECENTLY A FRENCH GROUP DISCOVERED A NEW LASER HOST LANTHANUM MAGNESIUM HEXAALUMINATE (LMAO, LAMGA111019). LASER OPERATION IN CR-DOPED, ND-DOPED, AND CR, ND-DOPED LMAO HAS BEEN REPORTED. THE PRESENT PROPOSAL IS TO EVALUATETI:LMAO FOR SOLID-STATE LASER APPLICATIONS. IT IS A PROMI- SING LASER CYSTAL, BUT HAS NOT BEEN EVALUATED SO FAR. DUE TO THE SIMPLE 3D1 CONFIGURATION OF TI3+, THERE IS NO EVIDENCE OF EXCITED STATE ABSORPTION, AND THIS GIVES RISE TOTO THE POSSIBILITY OF EFFICIENT TI-DOPED LASERS. THE MA- JOR DISADVANTAGE OF THE TI:A1203 IS THE RELATIVELY SHORT FLUORESCENCE LIFETIME OF 3.2 MICROSECONDS. THE TI SITED IN A1203 IS DISTORTED, WHICH GIVES IT OSCILLATOR STRENGTH. THEAVAILABILITY OF SYMMETRICAL SITES LMAO IS EXPECTED TO SHOW A LONGER FLUORESCENCE LIFETIME FOR TI IN TI:LMAO. IN ORDER TO PRODUCE AN EFFICIENT TI LASER, IT IS NECESSARY TO RETAIN THE DOPANT AS TI3+; THE TI4+ IS KNOWN TO SHOW AN ABSORPTION BAND IN THE LASING WAVELENGTH. CURRENTLY THE HIGHEST QUALITY TI:A12O3 CRYSTALS ARE GROWN USING THE HEAT EXCHANGER METHOD (HEMTM). THE PROPOSED PROGRAM COMBINES THE KNOWN ADVANTAGE OF THE TI DOPANT, LMAO HOST AND HEM CRYSTAL GROWTH TO SHOW FEASIBILITYOF PRODUCING TI:LMAO CRYSTALS FOR TUNABLE SOLID-STATE LASER APPLICATIONS. THIS APPROACH IS EXPECTED TO YIELD A NEW TUNABLE SOLID-STATE LASER WITH PROPERTIES DIFFERENT FROMANY KNOWN MATERIAL IN ITS CLASS TODAY.