MgO添加LiNbO_3単結晶の育成と光損傷特性(<特集>バルク成長)

抄録

Three types of LiNbO_3 single crystals were grown from melt doped with 1, 3 and 5 mol% of MgO. Homogeneities of these crystals without subgrain boundaries are useful enough for optical device substrates. No optical damage was observed in these crystals under irradiation of Ar laser with an incident power of 44 W/cm^2 and an exposure time of up to 10 min. However, optical damage was observed in the second harmonic generation of intracavity frequency doubling at room temperature with a diode-laser-pumped CW Nd: YAG laser and 1 mol% MgO doped LiNbO_3. On the other hand, the bulk laser damage threshold for MgO 1 mol% doped crystal is as high as 14 GW/cm^2 for pulse YLF laser (1.053,μm, 1 ns).