We fabricate a PCF coil sensor for water-depth sensing by winding a PCF on a plastic straw. Due to the bending-induced birefringence along the PCF, we can observe clear interference pattern in the output spectrum by placing the PCF coil into a Sagnac fiber loop. As we horizontally immerse the fabricated PCF coil into water, a nonlinear relationship between the water depth and the wavelength shift can be obtained. We have also measured the interference spectrum by vertically immersing the PCF coil into water. We can observe a linear relationship between the water depth and the wavelength shift, and the measured water-depth sensitivity for vertical immersion is -1.17 nm/mm.

Date Published: 3 May 2013
PDF: 6 pages
Proc. SPIE 8775, Micro-structured and Specialty Optical Fibres II, 877506 (3 May 2013); doi: 10.1117/12.2017093

Published in SPIE Proceedings Vol. 8775:
Micro-structured and Specialty Optical Fibres II
Kyriacos Kalli; Jiri Kanka; Alexis Mendez, Editor(s)