Polymeric \(N\)-stage serial-cascaded four-port optical router with scalable \(3N\) channel wavelengths for wideband signal routing application

Device architecture and design scheme of a universal \(N\)-stage cascaded polymer four-port optical router with scalable 3\(N\) channel wavelengths are proposed. Basic cross-coupling two-microring resonator routing element based on polymer materials is optimized for single-mode transmission, low optical loss and phase-match between microring waveguide and channel waveguide. Then, a one-stage four-port optical router is constructed using four-group basic routing elements, which has 12 possible I/O routing paths and 3 channel wavelengths. The insertion losses of each channel wavelength along every routing path are within the range of 0.04–0.63 dB, the maximum crosstalk between the on-port along each routing path and other off-ports is less than \(-39\) dB, and the device footprint size is \(\sim \)0.13 mm\(^{2}\). Compared with the previously reported four-port silicon optical routers, this device possesses similar ring radius (\(\sim \)10 \(\upmu \)m) and device size (\(<\)1 mm\(^{2})\). Aiming at wideband signal routing applications, we then construct a universal \(N\)-stage cascaded polymer four-port optical router possessing scalable 3\(N\) channel wavelengths. The proposed routing structure has potential application in photonic networks-on-chip, because of low insertion loss, low crosstalk, small footprint size, and scalable wideband 3\(N\) routing wavelengths.