LASING CHARACTERISTICS OF A DIODE-PUMPED CAGDALO4-ND3+ CRYSTAL

A new Nd3+-doped CaGdAlO4 laser crystal was investigated. This crystal was grown by the Czochralski method and the atomic concentration of N d3+ in the melt was 2%. The absorption and luminescence spectra were a nalysed and the Stark structure of the upper and lower active levels w as determined. The lifetime of the upper level was similar to 140 mu s . The stimulated emission cross section at the 1078 nm wavelength was 1.1.10(-19) sm(-2) for the E parallel to c polarisation. A GaAlAs diod e, with an output power of 3 W emitted at the wavelength 806.5 Mn, was used as the pump source. The slope efficiency was 37% at the 1078 mm wavelength when the output-mirror transmission was 5%. The output radi ation power of the crystal laser was 360 mW when the absorbed pump pow er was 1.29 W.