A peanut taper based Mach-Zehnder interferometric sensor for strain and temperature discrimination

• A cascaded MZI sensor is proposed for strain and temperature discrimination. • A peanut taper structure is used to connect SMF and PMF to constitute the MZI sensor. • The proposed sensor is simple, robust, cost effective and with easy fabrication. • The discrimination errors are as low as ±5.48 μ ε and ±0.21 °C. A Mach-Zehnder interferometric optical fiber sensor is proposed and demonstrated for strain and temperature discrimination. The sensor is fabricated by connecting a standard single mode fiber and a commercialized panda-type polarization maintaining fiber between the lead-in fiber and the lead-out fiber using three peanut-shaped up-tapers. Thanks to the different responses to strain and temperature of the single mode fiber and the polarization maintaining fiber, the sensor is able to achieve strain and temperature discrimination. Experiment results show that the sensor is capable of obtaining low discrimination errors of ±5.48 μ ε and ±0.21 °C for strain and temperature respectively. Besides, the proposed sensor is robust, cost-effective and easy to fabricate, which allows it a potential candidate for implementing simultaneous measurement of strain and temperature.