Micromachining of photonic bandgap fiber using focused ion beam milling technique

In this paper, a micromachining technique was reported that processing of photonic bandgap fiber (PBGF) was using focused ion beam (FIB) milling. PBGFs can be filled with fluid, allowing light to interact with the fluid while it is guided. Therefore, PBGFs are now widely used in ever-widening areas of science and technology. PBGFs of a honeycomb-structure with a hollow-core surrounded by microstructured cladding, and the widths of the thin silica struts are typically 40 to 50 nm. The FIB milling technique was used for micromachining to improve the sensitivity of PBGF gas sensors in this study. And a measurement system based on the PBGF gas cell has also been developed and implemented. The absorption measurements of acetylene gas and methane gas have been investigated. The experimental results clearly indicated that the high sensitivity of gas detection due to the long interaction path length provided by PBGF.