High contrast grating embedded multi-bus micro-optical triple ring-resonated temperature sensor design and simulation

The article introduces a novel attempt to design and simulate a high-contrast grating embedded micro-optical triple ring-resonance temperature sensor in the Z-domain. The sensor is configured with three waveguide rings, having different ring radii, and establishes ring resonance with the two linear waveguides. The only sensor element incorporated is the Bragg grating, which offers a high-index contrast between the adjacent cells and is modelled as an individual cell transfer function in the Z-domain. The transfer function formulation considers a cascade structure orientation and a uniform cell width of the grating and includes a phase term to address the refractive index differences. The signal flow graph representation of the composite triple ring-resonated Bragg grating sensor is also obtained, and, using Mason’s gain formula, the transmission transfer function is determined. The stated methodology exclusively relies on the unity-delay perturbation from $z^{-1}$ to $z^{-(1+∆M)}$ and the execution of the delay line signal processing technique, and illustrating the sensor’s spectral response for 0–50⁰ C temperature variation. The MATLAB platform is preferred for the simulation work and frequency response visualization. Finally, optical attributes like free spectral range, peak transmission, and spectrum shift magnitude are measured to examine the sensor response profiles.