Tunable laser oscillation with optical switches and grating on polysilane optical waveguides

Polysilane waveguides present advantages of ease in processing using photo-bleaching technology for drawing Bragg grating on the polysilane film and a larger thermo-optic (T/O) effect more than silica. In this paper we present the tunable lasers (TLs) composed of the LD module and the optical switch and grating circuits, and those characteristics. The TLs oscillate with the reflected wave at the Bragg grating. The switches and Bragg gratings, which are fabricated on the polysilane waveguide, are used for rough and fine tuning operations. The switches are composed of directional couplers with the thin film metal heaters. A channel selection at each output port is performed by choosing specific heaters. The wavelength fine tuning is performed with T/O effect on the Bragg grating. The laser oscillation with the monolithic optical circuit showed that the oscillation wavelength was 1564.16 nm, laser power was -9 dBm, oscillation bandwidth was less than 0.1 nm and the power ratio between main and side modes was more than 30 dB.