Single-frequency Er ³⁺ -doped silica-basedplanar waveguide laser withintegrated photo-imprinted Bragg reflectors

Single-longitudinal-mode operation of Er3+-P2O5-codoped silica planar waveguide lasers which are equipped with integrated Bragg grating reflectors is demonstrated, with a polarised output of 340 µW at 1546 nm. The gratings are photo-imprinted using 193 nm light exposure through a phase mask in GeO2-free optical waveguides that have been sensitised by H2 loading.