Optimization of carrier-depletion silicon optical phase shifter

The optimization of the cross-sectional geometry and doping concentrations of the $p$–$n$-junction in an electro-optic phase shifter, based on the depletion of free carriers in a silicon waveguide, has been performed using the gradient descent method. The configuration obtained through numerical simulation achieves a balance between phase shift efficiency and propagation loss. Additionally, a range of geometrical parameters ensuring single-mode operation in highly doped rib waveguides has been identified. The proposed optimization methodology and resulting findings offer valuable insights for the design of integrated photonic devices.