Sensitivity optimization of monolithic integrated refractive index sensor based on grating LED

Abstract

In this study, we present a potential ultra-thin refractive index sensor model that utilizes a monolithically integrated gallium nitride-based light-emitting diode platform. This light-emitting diode not only emits light but also detects changes in refractive index. The sensitivity of this sensor is defined as the response of light extraction efficiency to unit changes in refractive index. We have incorporated a one-dimensional grating on the surface of the light-emitting diode to investigate the effects of the grating’s modulation on the light field and the sensor’s sensitivity.Through strategic optimization of the grating structure, we have significantly enhanced the sensitivity of the sensor. Our results indicate that, compared to a conventional flat light-emitting diode, the optimized grating structure increases the light extraction efficiency by approximately 2 to 3 times. Furthermore, the sensitivity of the sensor has achieved a maximal enhancement of up to 41-fold.The device offers a compact design and demonstrates high levels of light extraction efficiency and sensitivity, making it highly suitable for monolithic integration in optical sensing applications. This advancement provides a substantial contribution to the field of optical sensing, indicating promising potential for future research and application.