Chalcogenides are materials that substantially consist of sulphur, selenium, and tellurium. Their dielectric properties
can be tuned by thermally induced structural phase transitions, photostructural transitions, and dissolution
of metal dopants. We have designed active photonic structures using a range of `tuneable' chalcogenides. The
resonant frequency of plasmonic structures was tuned over a 100 nm band in the visible, metal-chalcogenidemetal
structures provide tuning of over a band of 0.5 μm in the mid-infrared, and hyperbolic metamaterials
incorporating chalcogenides provide a means to alter the radiative decay rate of
In this work, we present the optical characterization of a two-dimensional (2D) <i>L3</i> photonic crystal (PhC) cavity biosensor in visible region by using 3D Finite Difference Time Domain (FDTD) method. The sensor is based on GaN material and integrated with a microfluidic channel. Sensing is performed by measuring the wavelength shift of the PhC cavity resonant peak, whose spectral position is sensitive to refractive index changes of dielectric material inside microfluidic channel. We simulate the PhC cavity with water (n=1.33) and two immersion oils (n=1.48 and n=1.518) overlaid. Spectral peak width was found to be 9.8nm around 650nm. A spectral shift of peak wavelength with index change of 35nm/RIU was observed. Measured peak shift (Δλ = 6.5<i>nm</i>) corresponds to a detectable index change Δ<i>n</i> = 0.188.