Proposal of simple gas sensor based on micro structure optical fiber

This paper presents a simple structure of photonic crystal fiber (PCF) based gas sensors. Gas sensors can be used in gas production facilities for safe measurement. The index guiding properties of two rings circular PCF have been analysed for different wavelength with the variation of the diameters of air holes in core and cladding. Finite-element method has been applied for numerical analysis. At the wavelength λ=1.66μm obtained maximum sensitivity is 13.94% and at the same time the confinement loss of the fiber is 2.74×10^-4 dB/m. The proposed structure is more flexible for its high sensitivity, low confinement loss and simple structure compare to early proposed high sensitivity chemical sensor PCFs with a hollow high index ring defect at the centre.