Proposal of a simple structure photonic crystal fiber for lower indexed chemical sensing

In this paper, a simple two layer photonic crystal fiber has been proposed. The proposed PCF shows higher sensitivity as a chemical sensor for lower refractive index chemicals Ethanol and Methanol. The proposed structure also reduces confinement loss. Micro structured array of elliptical air holes in the core has been used for better sensitivity. A full vectorial finite element method (FEM) was used for the investigation of the proposed chemical sensor for its different geometrical properties. The investigation depicts the impact of various geometrical properties like inner and outer layer diameters and pitch values on sensitivity and confinement loss. The simplicity and the higher results of the proposed PCF have been used for lower refractive index chemical sensor. The proposed PCF shows a higher sensitivity 40.32% for Ethanol and 34.90% for Methanol at the wavelength 1.33 μm. Besides that, the proposed two layers PCF sense the chemicals in a wide range of wavelength from 0.5 μm to 1.5 μm.