Fabrication of Inline Micro Air Cavity With Choice-Based Dimensions

Abstract

We propose a highly effective, and reproducible procedure for the fabrication of inline micro air cavity which plays a vital role in Fabry-Perot-based interferometric sensors. The micro air cavity is fabricated by splicing the single-mode fiber with hollow core photonic crystal fiber (HCPCF) and its dimensions can be well controlled by controlling a series of parameters, such as length of HCPCF and various splicing parameters, such as taper length, overlap of two fibers, and a number of arcs. Experimental results show that microcavities with horizontal and vertical length ranging from very low values ( $10~\mu \text{m}$ and $14~\mu \text{m}$ ) to very high values ( $124~\mu \text{m}$ and $127~\mu \text{m}$ ) has been fabricated with high reproducibility. This procedure can be employed to fabricate micro air cavities with any dimension within this range depending upon the user requirement. Furthermore, an application of the micro air cavity-based probes is studied by analyzing the response of one of the probe to axial strain.