Four-Channel, Silicon Photonic, Wavelength Multiplexer-Demultiplexer with High Channel Isolations

We present a four-channel, silicon-photonic, wavelength multiplexer-demultiplexer made using cascaded contra-directional couplers with adjacent and non-adjacent channel isolations of at least 37 dB and 45 dB, respectively. The device's maximum insertion-loss is 0.72 dB.