Single‐mode–multimode–single‐mode fiber structures for simultaneous measurement of strain and temperature

This article presents two related techniques for the simultaneous measurement of strain and temperature: (1) using two single‐mode–multimode–single‐mode (SMS) fiber structures accompanied with an optical spectral analyzer (OSA); (2) using three SMS fiber structures and a ratiometric power measurement system.Experimental results show that (1) the technique accompanied with an OSA has a resolution of 1.64 με for strain in the range from 0 to 1000 με and 0.11°C for temperature and (2) the technique based on ratiometric system offers a resolution of better than 2 με for strain measurements in the range from 0 to 1000 με and a resolution better than 0.84°C for temperature.