Low Loss Polymer Wavelength (De)multiplexer Interposing Si Waveguide and Single-mode Fiber Using Topology Optimization

We demonstrate an ultra-compact polymer wave-length (de)multiplexer also function as interposer between Si and optical fiber using gradient-based topology optimization and downhill simplex method with an excess waveguide propagation loss of of 0.84 dB and 1.06 dB at 1310 nm and 1550 nm, respectively.