Silicon Photonics is today one of the most important technologies around the world due to its level of maturity which can offer huge innovative designs and new integrated systems to be applied in several research fields such as optics communications, sensing, medicine, and aerospace, among others. Due to a growing need to develop compact sensors capable of acquiring biological and environmental measurements, optical and spectroscopic methods are the most promising approaches to reach the requirements of this type of sensor. Although there are some compact spectroscopic sensors based on free-space optical systems, further miniaturization, and weight reduction while maintaining high wavelength resolution is still a challenge. To overcome these issues, Arrayed Waveguide Gratings (AWG) present qualities and characteristics that can satisfy both requirements.

This work presents a useful procedure to design an integrated sensor under the SOI platform for applications in the NIR/MIR infrared band. Based on multiple AWGs in combination with other key photonic devices such as: double-ring resonators, thermal phase shifters, waveguide tapers, and others, an innovate sensor can be designed. The proposed strategy allows us to optimize specific characteristics of the spectral response to match the absorption spectrum of the element to be detected, as well as the footprint of this passive sensor. This goal can be reached using a full study of the key design parameter dependence for every optical circuit used. We have validated the carried-out methodology with this device and optimized the AWG designs for sensing applications.