NIR Spectrum Analysis of Natural Gas Based on Hollow-Core Photonic Bandgap Fiber

In this paper, we present a quantitative near-infrared spectroscopy measurement of the chemical compositions of gas mixtures, such as natural gas, based on a photonic bandgap fiber gas cell. The absorption spectra of the methane and ethane gases were investigated in the near-infrared region. The absorption lines of the ethane gas were observed in the 1600-1616-nm region, and were totally different from those of the methane gas. To our knowledge, this is the first study to measure the individual absorption lines of ethane in this range of wavelengths, and our finding has a great potential for sensing highly sensitive gases.