Electrical characteristics of silicon-on-insulator (SOI) phase modulator

This paper highlights the study of carrier injection effect on silicon-on-insulator waveguide with trapezoidal cross section structure. The n-p-n structure will be employed to study the device performance in terms of modulation efficiency and absorption loss. The characterization of the proposed device will be carried out by 2D Silvaco CAD software under different applied voltages. The device is designed to be operated at 1.55μm optical wavelength with single mode behavior. The injection of free carriers into the guiding region changes the refractive index and the modelling has been carried out by Atlas from Silvaco to determine the electrical characteristics. From the simulation, the change of the refractive index, Δn from which we can estimate the phase shift, ΔΦ and the device length that is required for phase shift, Lπ are reported. It is predicted that the performance of trapezoidal cross section waveguide is better than conventional rib waveguide.