Highly sensitive bend sensor based on Mach-Zehnder interferometer using photonic crystal fiber

Optical fiber bend sensor with photonic crystal fiber (PCF) based Mach-Zehnder interferometer (MZI) is demonstrated experimentally. The results show that the PCF-based MZI is sensitive to bending with a sensitivity of 3.046 nm/m(-1) and is independent on temperature with a sensitivity of 0.0019 nm/degrees C, making it the best candidate for temperature insensitive bend sensors. To that end, another kind of bend sensor with higher sensitivity of 5.129 nm/m(-1) is proposed, which is constructed by combining an LPFG and an MZI with zero offset at the second splice mentioned above. (C) 2011 Elsevier B.V. All rights reserved.