Ultracompact gas-sensor based on a 2D photonic crystal waveguide incorporating with tapered microcavity
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Date
2021
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Publisher
Université de M'sila
Abstract
In this study, a new ultra compact gas-sensor, based on a 2D photonic crystal
waveguide incorporating with tapered microcavity, is designed to detect small refractive index
changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the
sandwiched waveguide on Si slab with triangular lattice. The properties of the sensor are
simulated by using the plane wave expansion (PWE) method and the finite-difference timedomain
(FDTD) algorithm. The transmission spectra of the sensor with different ambient
refractive indices ranging from n = 1.0 to n = 1.01 are calculated. The calculation results show
that a change in ambient refractive index of Δn=1×10-4is apparent. The proposed sensor
achieves a sensitivity (Δλ/Δn) of 523.2 nm/RIU. It was found that the resonance wavelength is
a linear function of the refractive index in under study range. The sensor is appropriate for
detecting homogeneous media