Photonic integrated circuit microchip design of two-wave mixing interferometer for FBG acoustic emission sensor signal demodulation

A photonic integrated adaptive two-wave mixing (TWM) interferometer is designed for demodulation of FBG acoustic emission sensor signals, whose various optical elements are integrated in a substrate material with photorefractive properties. A ridge waveguide based on InP:Fe is designed. Each component of the photonic integrated TWM interferometer is analyzed and optimized to minimize the loss of light in the transmission of the TWM interferometer and obtain the best demodulation performance. The feasibility of the optimized structure of the photonic integrated adaptive TWM interferometer is verified in theory, and the optimized structure will contribute to the miniaturization and integration of the TWM demodulation system based on InP:Fe.