Laser-diode pumping of waveguide laser based on Nd-doped silica planar lightwave circuit

The authors describes an improvement in the lasing threshold in Nd-doped silica planar-lightwave-circuit (PLC)-type lasers fabricated on Si substrates in which the scattering loss was reduced by an improved fabrication technique. Lasers with core widths from 6 to 30 mu m were fabricated by flame hydrolysis deposition and reactive ion etching techniques. Based on an investigation of the lasing threshold dependence on core width, a minimum lasing threshold was obtained in a waveguide laser with an 8 mu m wide core. A threshold of 25 mW and a slope efficiency of 1.2% for laser-diode pumping at 805 nm were obtained in the waveguide laser.>