Investigation of temperature dependence of tapered optical fibers

The temperature-sensitive performance of tapered optical fibers, characterized by high sensitivity and stability, is comprehensively studied. This sensor, based on the coupling between core and cladding modes resulting in Mach-Zehnder interference (MZI), adopts a single-mode fiber (SMF)-multimode fiber (MMF)-tapered SMF-MMFSMF (SMTMS) hybrid structure. The relationship between resonance wavelength shifts and surrounding temperatures is explored to evaluate its temperature sensitivity. Experimental results reveal that the multimode fiber length and the length of the conical region are critical factors affecting temperature sensitivity. Various SMTMS structures with differing MMF lengths and conical region lengths are fabricated, achieving a maximum sensitivity of -145.8 pm/degrees C. Notably, the sensor exhibits exceptional stability under laboratory conditions, further demonstrating its reliability for practical applications. With its high sensitivity and robust stability, this sensor shows great promise for applications in fields such as healthcare and environmental monitoring.