POSSIBLE TRENDS FOR THE GROWTH OF LOW SCATTERING ND-YVO4 LASER CRYSTALS - PHASE-RELATIONS - GROWTH TECHNIQUES

The Nd:YVO4 single crystal is one of the most promising laser hosts fo r micro and diode-pumped solid state lasers due to its outstanding las er characteristics. However, the growth difficulties encountered can s ignificantly restrain its widespread high-tech applications. The inclu sions which are mainly submicron size precipitates, and the color cent er problems commonly originate from the defects of valency states. The presence of non-pentavalent vanadium ions in the V2O5 starting materi al, the related valency defects in the YVO4 compound created by the re action process, and the incongruent vaporization of vanadium oxides to gether with YVO4 melt will primarily determine the congruency as a typ ical off-stoichiometric effect. This work concludes that the simple Cz ochralski (CZ) growth technique cannot produce scattering-free and sto ichiometric YVO4 crystals, nevertheless the top-seeded solution growth (TSSG) and liquid phase epitaxial (LPE) techniques provide possible a lternatives for better quality crystal production Several specific asp ects of the phase relations of YVO4 crystals prepared by CZ, TSSG and LPE techniques are surveyed in this paper.