WDM coupler for signal and second harmonic pump based on silica-based PLC for hybrid integration of linear and nonlinear optical devices

We fabricated a low-loss wavelength division multi/demultiplexing coupler using silica-based planar lightwave circuits for hybrid integration with nonlinear optical waveguides as an advanced optical signal processing technology. We can use this coupler to multi/demultiplex 1.56- and 0.78-μm lights with low loss by modifying the gap distance of the directional coupler.