Sensing of volatile organic compounds using one-dimensional photonic crystal Bloch surface waves and internal optical modes

Abstract

Bloch surface wave (BSW) and internal optical modes (IOMs) of one-dimensional photonic crystals (1DPhCs) have been explored for sensing purposes in the photonic crystal coupled reflectance (PCCR) geometry using the Kretschmann-Raether (KR) prism-coupling configuration. 1DPhCs coated with polyvinyl alcohol (PVA) thin films of two distinct thicknesses: 18 nm (referred to as PhC18) and 24 nm (referred to as PhC24) were fabricated. The response of the PCCR to the changes occurring in the PVA coated 1DPhC structures were studied by spraying volatile organic compounds, 1-propanol and 2-propanol onto the surface of the 1DPhCs. The BSWs excited under TE polarization are found to be very sensitive to perturbations at the 1DPhC interface. 1-propanol displays larger wavelength shifts and longer recovery times of the 1DPhC modes than 2-propanol because of its lower vapor pressure and higher reactivity to PVA.