Low Loss and Low Crosstalk Waveguide Crossings Designed by Wavefront Matching Method

We designed waveguide crossings with small angles by the wavefront matching method to reduce excess loss and crosstalk. The designed waveguide crossings were fabricated using silica-based planar lightwave circuit (PLC) technology. We experimentally obtained excess loss and crosstalk values of less than 0.3 and -30 dB, respectively, for a crossing angle of 5deg, and of less than 0.1 and -38 dB, respectively, for an angle of 20deg, in the 1530-1565-nm wavelength range. The designed waveguide crossings are promising as basic circuit elements for realizing more compact PLC devices