Design and demodulation stability analysis of cascaded photonic crystal nanobeam cavities for dual-parameter detection

Abstract

The influence of dual-parameter sensor resolution on the demodulation results is usually ignored. We present a cascaded photonic crystal nanobeam cavities sensor (CPCNCS) on the silicon-on-insulator (SOI) platform that can effectively suppress demodulation deviations. The sensor consists of a slotted photonic crystal (PhC) nanobeam cavity (cav1) and an unslotted PhC nanobeam cavity (cav2). To describe the ability for suppressing demodulation deviations, we propose the concept of demodulation stability factor and perform a quantitative analysis. The vectorization analysis method provides a clear design idea for dual-parameter sensors with high demodulation stability factor. The demodulation stability factor of the proposed CPCNCS is as high as 2497 nm RIU−1 K−1, indicating that the proposed sensor has a superior performance in demodulating refractive index and temperature.