A simple structure of PCF based sensor for sensing sulfur dioxide gas with high sensitivity and better birefringence

Abstract

Abstract This paper describes a micro-cored photonic crystal fiber-based gas sensor that uses a simple structure and proper analysis has done to detect sulfur dioxide gas. SO2 is a significant air pollutant that may aggravate existing respiratory and cardiovascular diseases. The numerical investigation has been done in a range of wavelengths from 0.9 ​μm to 1.1 ​μm and as usual, the proposed structure is numerically analyzed by using the complete finite element method. A Perfectly Matched Layer (PML) is used to investigate the optical parameters. We tested the performance of the designed PCFs for sensing sulfur dioxide as a gas sample. We designed the core section of the proposed structure with only a circular shape hole to minimize design complexity. The relative sensitivity can be increased by changing the diameter of the air holes in the microstructure core, cladding holes even the thickness of the PML. The proposed sensor's test is carried out on different Pitch values, PML thickness values, core region's hole diameter variations, cladding hole diameter variations. At fixed wavelength of 1 ​μm, the maximum relative sensitivity obtained here is around 70% with a better birefringence value 1.0 ​× ​10−03 and lower confinement loss.

Keywords

• Photonic crystal fiber
• Gas sensor
• Finite element method
• Perfectly matched layer
• Sensitivity
• Birefringence