Theoretical investigation and optimization of rotation sensing in the new photonic crystal gyroscope based on the Sagnac effect using nonlinear photonic resonators

Abstract

In this research, the angular rotation speed in a passive photonic gyroscope based on the combination of side nanoring resonators and compensating waveguides has been analyzed by creating nonlinear effects in the control factors of the rings using the Sagnac effect. This structure consists of a central waveguide, two identical square resonators, and an almost U-shaped waveguide. The U-shaped waveguide causes coupling between the two resonators in a counterclockwise (CCW) mode. In this structure, a phase shift has been created in the output from the interference of two clockwise (CW) and CCW waves inside the resonators, and according to this phase shift and the central wavelength, the angular rotation speed has been estimated. In the proposed design of the gyroscope, by managing the nonlinear effects in the radius and refractive index (RI) of the coupling and inner rods, we have been able to control the changes in power, phase, and wavelength of the output from the device. With the increase in the intensity of power, the output power has an increasing slope at first, and at the point of creating a nonlinear effect in the sensor, the output power slope decreases. Also, this nonlinear effect directly affects the output phase of the structure. The maximum angular rotation speed in this gyroscope was [Formula: see text]/s. By changing the RI of the inner rods from 3.2 to 3.7, the maximum output-to-input power ratio changes from 0.38 W/[Formula: see text]m2 to 0.75 W/[Formula: see text]m2. By changing the radius of the coupling rods from 93 nm to 97 nm, the maximum power ratio decreases from 0.78 W/[Formula: see text]m2 to 0.55 W/[Formula: see text]m2. The field distribution profile and photonic bandgap in this gyroscope have been analyzed using the finite-difference time-domain (FDTD) and plane-wave expansion (PWE) methods, respectively. Also, the gyroscope has a footprint of 163.5 [Formula: see text]m2.