Measurement of Low Gas Concentrations Using Photonic Bandgap Fiber Cell

In this paper, we present a novel low-loss splice for use between the photonic bandgap fiber (PBGF) and the conventional solid-core fiber to make PBGFs more functional. Furthermore, the hollow-core and the holes in the cladding of PBGF act as gas pipes. Using the proposed splice, a measurement system for low gas concentrations based on the PBGF cell has been developed and implemented. Experiments for measuring ammonia (NH₃) gas at the ppm level were performed. The basic peak agreed well with the database of the Pacific Northwest National Laboratory (PNNL), meaning that this method can be used to accurately and effectively measure gas concentration. The constructed gas cells are compact and cost-effective for sensitive, rapid, and continuous measurement of gases.