Planar photonic crystal based multifunctional sensors

A planar photonic crystal (PPC) structure capable of simultaneous detection of multiple parameters is presented in this paper. We analytically and numerically demonstrate that the reflection spectrum of the PPC structure exhibits multiple high-Q resonant modes that could respond distinctively to different external perturbations, rendering the PPC sensor superior capabilities for multiparameter sensing. We further demonstrate simultaneous pressure and temperature sensing with a PPC sensor. Other advantages of this device include efficient free-spaceto- multimode coupling, high sensitivity, on-chip integration, and wafer-scale fabrications. (C) 2017 Optical Society of America