Theoretical Analysis of Silicon-Based Integrated-Optic Mach-Zehnder Pressure Sensors

Silicon-based Mach-Zehnder integrated-optic pressure sensors are investigated in this article. Several structures proposed in the literature are examined and performance parameters such as power leakage towards the Si substrate, radiation loss as a function of the Y-junction aperture angle, and halfwave pressure are analyzed. Modeling of the material deformation characteristics and refractive index change as a function of the applied pressure is carried out by using the finite-difference technique. The sensor optical characteristics and waveguiding properties are computed by using the finite-difference beam-propagation method (FD-BPM) and the extended effective index method (EEIM). Guidelines for performance optimization are proposed.