C- and L-band planar delay Interferometer for DPSK decoders

The superior performances of silica-on-silicon optical components allow the design of robust and stable delay interferometers (DIs). For differential phase-shift keying (DPSK) applications when the bite rate is specified, a unique device is needed to cover the C- and L-bands. With a polarization-dependent loss better than 0.1 dB, a polarization-dependent frequency shift better than 2 GHz, and an extension ratio better than 21 dB, we show that the fabricated DI is the ideal candidate for DPSK decoders.