One-Dimensional Defect Layer Photonic Crystal Sensor for Purity Assessment of Organic Solvents

This paper presents the design and analysis of a one-dimensional defect layer photonic crystal (1D-DLPC) sensor for the assessment of the purity of chemical solvents with enhanced accuracy. Chemical solvents are frequently used in chemical processes as reaction mediums. It is essential to ascertain its purity since impurities can significantly affect the outcome of the reaction. The structure of the proposed one-dimensional defect layer photonic crystal sensor consists of a defect layer sandwiched between alternate layers of ZnO and SiO₂ organized with a certain periodicity. It has been shown that the localized defect modes inside the structure can detect minute refractive index changes based on the degree of impurity of chemical solvents. Simulation studies have been performed through the transfer matrix method (TMM) and the performance of the design is evaluated using several metrics such as sensitivity, full width at half-maximum, figure of merit, quality factor, and dynamic range. Results indicate that the designed one-dimensional defect layer photonic crystal sensor has a significantly high efficiency and is suitable for detecting impure solvents.