Highly Sensitive On-Chip Grating-Based Optical Sensor on Glass Substrate: Cost-Effective Design

Abstract

This paper presents a novel on-chip optical sensing system using ion exchange technology and phase-shifted Bragg grating design. The sensor geometry has been optimized using a finite difference time domain (FDTD) solver to achieve maximum sensitivity and figure of merit (FOM). The proposed design offers high sensitivity to changes in refractive index and low fabrication costs. The ion exchange process used to create the sensor allows for precise refractive index control, optimizing the sensor’s sensitivity and FOM. A graded-index waveguide and a phase-shifted Bragg grating structure also contribute to the sensor’s high sensitivity. The proposed sensor design was tested for water-based sensing applications, achieving a FOM of 227.63 and a 343.1 nm/RIU sensitivity. These values are significantly higher than those reported for other Bragg grating sensors, highlighting the potential of the proposed design for high-performance sensing applications. The sensor’s high sensitivity and low fabrication costs make it a promising technology for future sensing and monitoring applications.