Neodymium-doped Calcium Niobium Gallium Garnet Laser Crystals Developed

Neodymium-doped calcium niobium gallium garnet (Nd:CNGG)is a new type laser crystal. The crystal has the low melting point(1470℃) and a disordered type structure. It has a broader absorption band at 808 nm which is emitted by laser diode (LD). Therefore, Nd:CNGG is suitable for LD pumping, the LD pumped all solid-state lasers can be made by using Nd:CNGG.In this study, Nd:CNGG single crystals of 25mm in diameter and above 80mm in length were successfully grown by the automatically pulling method from the melt. The grown crystals have plane interfaces and are free from cores. The phase of matter and structure of Nd:CNGG were determined, the optical spectra of Nd:CNGG crystals were measured. The extinction ratio of Nd:CNGG crystal is as high as 34 dB. The technical breakthroughs in growth of Nd:CNGG had been made. In particular, Continuous laser operation was achieved from Nd:CNGG pumped by LD. When the crystal wafer was end-pumped by one bar of LD with 807nm wavelength, the CW laser output power of 123.1 mW was obtained with slope efficiency of 22.3%.