Dispersion Characteristics for Critical Coupling in Micro Racetrack Resonator using SoI Integrated Photonics

This manuscript investigates the dispersion characteristics of an all-pass micro-racetrack resonator (MRTR) integrated with Silicon on Insulator (SOI) technology. The MRTR is operated under critical coupling condition. The design is based on a silicon (Si) rectangular waveguide, supporting first and second order quasi-TE modes at the operation wavelength of 1550 nm. Waveguide dimensions are optimized using confinement factor (CF) and mode effective area (MEA) to ensure efficient guiding. A comprehensive dispersion analysis is performed, focusing the amplitude of self-coupling coefficient (t(λ)) and amplitude of round-trip transfer coefficient (a(λ)). Air and silica glass (SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) are used as cladding materials to evaluate sensor performance over a refractive index range of 1 to 2. Results confirm the potential of the dispersion engineered MRTR for highresolution photonic sensing applications.