Design of a Dual-Mode Graphene-on-Microring Resonator for Optical Gas Sensing

Abstract

On-chip optical gas sensors, which use resonant shifts of cavities to detect molecular concentrations, have the advantages of high sensitivity, real-time detection, and compact footprint. However, such sensors are usually limited by a serious cross-sensitivity issue induced by environmental temperature variations. To overcome this limitation, we study a dual-mode graphene-on-microring resonator to accurately measure gas concentrations without suffering from temperature variations. To be specific, the influences of gas-induced graphene's optical conductivity changes and environmental temperature variations on effective refractive indices of TE 0 and TE 1 modes in the resonator can be decoupled based on the modal linear independent responses. With this method, we designed a nitrogen dioxide sensor with a sensitivity of 0.02 nm/ppm and a limit of detection of 0.5 ppm. Our study paves the way for developing on-chip optical gas sensors with excellent sensitivity and temperature stability.

In-Situ Study of Dynamics of Refractive Index Changes in Silicon Devices Induced by UV-light Irradiation

“…6(a). The resonance increases linearly with the chip temperature, due to the positive thermal-optic coefficients of silicon (1.8×10 -4 /C) and silicon oxide (9.6×10 -6 /C) [28]. From the linear fitting of Fig.…”

Integrated optoelectronics with two-dimensional materials

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Dyadic Green's function of partially filled graphene‐loaded rectangular waveguides

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