Smartphone-Based Refractive Index Optosensing Platform Using a DVD Grating

Abstract

A low-cost, smartphone-based optical diffraction grating refractometer is demonstrated. Its principle of operation is based on the dependence of the diffraction efficiency of a DVD grating on the surrounding refractive index. The studied configuration uses the built-in LED flashlight and camera of a smartphone as a light source and a detector, respectively, to image the DVD grating diffraction pattern. No additional optical accessories, such as lenses, fibers, filters, or pinholes, are employed. The refractive index sensor exhibits a linear response in the refractive index range of 1.333–1.358 RIU (refractive index unit), with a sensitivity of 32.4 RIU−1 and a resolution of 2 × 10−3 RIU at the refractive index of water. This performance makes the proposed scheme suitable for affinity-based biosensing and a promising optosensing refractometric platform for point-of-need applications.

Metasurface Micro/Nano-Optical Sensors: Principles and Applications

“…Enabled by the micro-fabrication technologies, vast optical elements based on diffractive microstructures are demonstrated, such as micro-gratings, , diffractive lenses, , Fresnel zone planes, diffractive diffusers, phase corrector plates, etc ., which are often referred to as diffractive optical elements (DOEs). Diffractive grating, one of the most widely used optical components, has already been miniaturized for microspectrometers and sensors. , Figure a shows an interesting work using a refractive index sensor based on a micro-grating from a digital video disc (DVD), which functions as an extension device of the smartphone . The refractive index sensor is realized by monitoring the diffraction efficiency variation of the DVD micro-grating using the camera of a smartphone, where the incident light is supplied by the light-emitting diode (LED) flashlight of the smartphone.…”

“…(a) Refractive index sensor based on diffractive grating from a DVD. Adapted with permission under a Creative Commons CC-BY License from ref . Copyright 2022 MDPI.…”

Feature Papers in Optical Sensors 2022

“…In the twelfth paper, by Barrios [ 12 ], a low-cost, smartphone-based optical diffraction grating refractometer is reported. Its principle of operation is based on the dependence of the diffraction efficiency of a DVD grating on the surrounding refractive index.…”