Crystallization-induced refractive index modulation on sapphire-derived fiber for ultrahigh temperature sensing.

Abstract

We have demonstrated crystallization-induced refractive index (RI) modulation on sapphire-derived fiber (SDF) showing superheat resistance and developed the SDF based Fabry-Perot interferometers (FPIs) for ultrahigh temperature sensing. The SDF is a special fiber with high concentration of alumina to silica in the fiber core region. Reheating and cooling the SDF by arc discharge generates mullite particles in the core region, which achieves RI modulation up to ~0.015. Such crystallized region in the SDF is explored as mirrors for FPI, showing a good linear response to temperature with sensitivity of ~13.2 pm/°C. Benefiting from superheat resistance of the crystallized SDF being mirrors, the developed SDF-FPI sensor is capable to withstand high temperature up to 1600°C, which is the highest working temperature for amorphous fiber. Moreover, the SDF-FPI sensor exhibits 6-hour stability at 1200°C. The crystallized SDF-FPIs with compactness, wide temperature working range, high sensitivity, and robustness show great potential application in harsh environment such as turbine engines, power plants, petrochemical, gas industry, etc.

• Authors: H Liu, F Pang, L Hong, Z Ma, L Huang, Z Wang, J Wen, Z Chen, T Wang
• Journal: Optics express (Opt Express) Vol. 27 Issue 5 Pg. 6201-6209 (Mar 04 2019) ISSN: 1094-4087 [Electronic] United States
• PMID: 30876210 (Publication Type: Journal Article)