Abstract

A highly sensitive temperature sensor is proposed and demonstrated based on a UV-curable polymer-infiltrated Mach–Zehnder interferometer (MZI) created in a graded index fiber (GIF). The device was constructed by splicing a half-pitch GIF between two single-mode fibers and creating an inner air cavity in one lateral side of the GIF core by means of femtosecond laser micromachining. The air cavity and the residual GIF core functioned as two interference arms of the MZI. Moreover, the GIF was used as a miniature in-fiber collimator to reduce insertion loss of the air cavity. Experimental results show such an MZI device has a high refractive index (RI) sensitivity of 24611.54 nm/RIU ($\mathrm{RI}=1.545–1.565$). Subsequently, thermo-sensitive polymer liquid was infiltrated into the air cavity, then cured with UV illumination, and annealed at 50°C for 12 h. The infiltrated MZI exhibits a high temperature sensitivity of $-13.27\mathrm{nm}/°\mathrm{C}$. In addition, this MZI also has excellent thermal stability and repeatability, compact structure, low insertion loss, and high fringe visibility. As such, the proposed MZI could be developed for high-accuracy temperature measurements in many areas such as biomedical or oceanographic applications.

© 2019 Optical Society of America

Highly sensitive hydrogen sensor based on an in-fiber Mach-Zehnder interferometer with polymer infiltration and Pt-loaded WO₃ coating

Bin Du, Jun He, Minghong Yang, Ying Wang, Xizhen Xu, Jiachen Wang, Zhe Zhang, Fengchan Zhang, Kuikui Guo, and Yiping Wang
Opt. Express 29(3) 4147-4158 (2021)

Highly sensitive temperature sensor based on an ultra-compact Mach–Zehnder interferometer with side-opened channels

Ming Deng, Leiguang Liu, Yong Zhao, Guolu Yin, and Tao Zhu
Opt. Lett. 42(18) 3549-3552 (2017)

Ultrasensitive refractive index sensor based on a Mach–Zehnder interferometer created in twin-core fiber

Zhengyong Li, Changrui Liao, Yiping Wang, Xiaopeng Dong, Shen Liu, Kaiming Yang, Qiao Wang, and Jiangtao Zhou
Opt. Lett. 39(17) 4982-4985 (2014)

Ultra-sensitive silicon temperature sensor based on cascaded Mach–Zehnder interferometers

Zuoqin Ding, Daoxin Dai, and Yaocheng Shi
Opt. Lett. 46(11) 2787-2790 (2021)

High-sensitivity temperature sensor based on anti-resonance in high-index polymer-coated optical fiber interferometers

Xiaokang Lian, Qiang Wu, Gerald Farrell, and Yuliya Semenova
Opt. Lett. 45(19) 5385-5388 (2020)