Heterogeneous all-solid multicore fiber based multipath Michelson interferometer for high temperature sensing

Abstract

A compact high temperature sensor utilizing a multipath Michelson interferometer (MI) structure based on weak coupling multicore fiber (MCF) is proposed and experimentally demonstrated. The device is fabricated by program-controlled tapering the spliced region between single mode fiber (SMF) and a segment of MCF. After that, a spherical reflective structure is formed by arc-fusion splicing the end face of MCF. Theoretical analysis has been implemented for this specific multipath MI structure; beam propagation method based simulation and corresponding experiments were performed to investigate the effect of taper and spherical end face on system's performance. Benefiting from the multipath interferences and heterogeneous structure between the center core and surrounding cores of the all-solid MCF, an enhanced temperature sensitivity of 165 pm/°C up to 900°C and a high-quality interference spectrum with 25 dB fringe visibility were achieved.

Refractive-index-modified-dot Fabry-Perot fiber probe fabricated by femtosecond laser for high-temperature sensing

“…LPFG-based high-temperature sensors [2] have a large cross sensitivity to fiber bending or strain, and they are relatively long (usually several centimeters). Various schemes including fiber tapers [3], special fibers fusion splicing [4][5][6][7][8][9][10][11][12] and mismatched core diameter structures [11,[13][14][15] have been exploited to construct MZIs and MIs. However, MZIs work in transmission, which are not very compact, not suitable for working in narrow space and remote sensing.…”

Photonic Crystal Fiber–Based Interferometric Sensors

“…Gao et al proposed an in-line PCF Michelson interferometer for label-free, real time and sensitive detection of DNA hybridization and methylation [61]. To fabricate the interferometer, Multicore fiber (MCF) based multipath Michelson interferometers have been proposed and demonstrated for high temperature sensing recently [64]. The reflective mirror was formed via arc-fusion splicing the fiber end face.…”

“…The seven cores acted as the different optical paths in the multipath Michelson interferometer. The device demonstrated a temperature sensitivity of 165 pm/ C in the temperature range of 250-900 C [64].…”

Application of MZI Symmetrical Structure With Fiber Balls and Seven-Core Fiber in Microdisplacement Measurement

“…Generally, each optical path difference induced by the combination of these modes could generate either interference weak or strong interference (depending on the intensity of the involved modes). Here, we only consider the dominant interference caused by the optical path difference (OPD) induced by the central core mode and the surrounding core mode of the MCF [16], so this structure still can be regarded as an MZI model [17], then the transmission spectrum intensity of the proposed interferometer can be explained as…”