High-sensitivity robust Mach-Zehnder interferometer sensor in ultra-compact format

A new type of fiber sensor called the mini-two-path Mach-Zehnder interferometer (MTP-MZI) sensor has been proposed and demonstrated for high-sensitivity curvature and temperature detection. The sensor is created by fusing two sections of single-mode fibers (SMFs) with an electric-arc technology. In the curvature experiment, the maximum intensity sensitivity is 112.6 dB/m−1 when the curvature changes from 0.005224 m−1 to 0.052245 m−1. As far as our knowledge, it has the highest sensitivity with the same scale in the MZI fiber sensors. Additionally, a temperature sensing performance has been measured within the range from 30 °C to 70 °C, and the maximum temperature sensitivity is 162 pm/°C. Compared with the two-path MZI with traditional meter-scale, the proposed MZI has the advantages of robustness, compact size, easy preparation, and packaging, which can open up new avenues for MZI in the application of multi-dimensional and multi-parameter sensing.