Thermo-Optic Phase-Profile Shaping of Bragg Gratings in Planar Silica Channel Waveguides

Bragg gratings in planar channel waveguides equipped with arrays of heating elements on top of them are presented. The latter allow for applying user-defined temperature distributions along the gratings and thereby quasi-arbitrary changes of the phase of the coupling coefficient of the grating. In this way, tunable second- and higher-order dispersion compensators can be realized as well as tunable single- or multichannel transmission filters.