Performance Analysis of High Contrast Sub Wavelength Grating for Biomedical Sensing Applications

Abstract

Traditional biosensing technologies have limitations such as complex sample preparation, expensive operating systems, and limited sensitivity. These constraints have driven the need for advanced sensing platforms with improved performance metrics. Recently, high-contrast subwavelength gratings (HCGs) and surface plasmon resonance have been suggested among the most powerful candidates in optical biosensing since they can manipulate light at a subwavelength scale with a high degree of freedom. Optical biosensors based on HCGs represent a rising class of optical sensors that allow label-free detection non-invasive diagnostics, and in situ place data acquisition, thus providing large advantages over conventional sensing technologies. High contrast subwavelength gratings (HCSGs) are periodic microstructures with a grating period smaller than the wavelength of incident light. These microstructures exploit resonant effects and photonic band gaps, which permit powerful light-material interactions required for sensitive detection mechanisms. Using these properties, HCGs can work as a promising platform for biosensing applications and eliminate the need for sophisticated approaches. In this research, a performance analytical study of high-contrast subwavelength gratings for biomedical sensing applications has been done and the goal is to improve our design and enlarge their utility in the detection of biomolecular interactions. A generic framework is developed to evaluate the performance of HCSG-based sensors, considering factors such as grating parameters (grating thickness, grating height, grating periods, etc.), the refractive index contrast, and functionality for biomolecular recognition. This research explores the optimization of HCSG-based biosensors, specifically focusing on their design parameters that affect performance metrics such as resolution, sensitivity, and detection limits. By using advanced simulation techniques, including FDTD (finite-difference time-domain) methods, the study analyses the various effect