Low-threshold transversely excited NdP5O14 laser

The threshold and efficiency of a transversely excited, CW NdP5O14 laser have been measured with 0.58-micron excitation from a dye laser and 0.8-micron excitation from a semiconductor laser. After fitting data for the threshold as a function of wavelength near 0.58 microns, the calculations were applied to the 0.80-micron Nd(3+) absorption band. With transverse excitation from high-radiance LED's or laser diodes, thresholds are calculated to be 4-8.5 mW at 0.80 microns, depending on pump bandwidth. Using an Al(x)Ga(1-x)As double-heterostructure laser diode pump, quasi-CW lasing was obtained in NdP5O14, with thresholds of about 7 mW and optical power conversion efficiency of about 7%.