We propose a scheme to optimize the adiabaticity of silicon 3-dB couplers for broadband operation and good fabrication tolerance. We use the invariant based inverse engineering to optimize the system evolution to be as as adiabatic as possible while ensuring that the resulting device parameters are smooth. Using the inverse engineering based optimization, a 125 µm long silicon 3-dB coupler with a maximum imbalance of 0.8 dB from 1.4 to 1.7 µm and good fabrication tolerance is obtained. The optimized waveguide widths and separation are smooth.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)