Gas sensing properties of index-guided PCF with air-core

The gas sensing properties of index-guided photonic crystal fiber (PCF) with air-core are investigated via full-vector finite element method. The relationships between the gas sensing properties of index-guided PCF with air-core and the fiber parameters, including the fiber length and the operating wavelength, have been discussed. The simulations show that the gas sensing sensitivity of the fiber increases significantly as the diameter of the air holes increases, and it decreases with the holes pitch. Compared with the traditional PCF, there is a great improvement in the sensing properties of our design. The results are helpful for designing high performance PCF for gases or liquids sensing.