Fiber optic temperature and strain sensor using dual Mach–Zehnder interferometers

Abstract

A fiber optic temperature and strain sensor using dual Mach–Zehnder interferometers (MZIs) is proposed. The dual MZIs were fabricated by fusion splicing of two different fibers between two single-mode fibers. The two fibers of thin-core fiber and small-cladding polarization maintaining fiber were fusion spliced with a core offset. As the responses of the two MZIs are different in terms of temperature and strain, simultaneous temperature and strain measurement were experimentally validated by selecting two resonant dips in the transmission spectrum to construct a matrix. Experimental results show that the proposed sensors had the maximum temperature sensitivity of 66.67 pm/°C and the maximum strain sensitivity of −2.0pm/µε. The minimum discriminated temperature and strain of the two proposed sensors were 0.20°C and 0.71 µε, and 0.33°C and 0.69 µε, respectively. The proposed sensor has promising application prospects due to the merits of ease of fabrication, low costs, and good resolution.

A Concise Review of the Progress in Photonic Sensing Devices

“…The two MZIs have different responses to temperature and strain, and simultaneous measurement of both was experimentally justified using resonant dips in the transmission spectrum. The proposed sensors had maximum temperature and strain sensitivities of 66.67 pm/ • C and −2.0 pm/µε, respectively, and could discriminate temperatures and strains as low as 0.20 • C and 0.71 µε, and 0.33 • C and 0.69 µε, respectively [94]. The sensor has potential applications due to its ease of fabrication, low costs, and good resolution.…”

“…The sensor demonstrates high-resolution temperature measurement and good stability in thermal cycle testing, with a maximum testing temperature of 800 • C [91]. Researchers have proposed an optical fiber temperature and strain sensor using dual MZIs that were assembled by fusion splicing of two different fibers [94]. The two MZIs have different responses to temperature and strain, and simultaneous measurement of both was experimentally justified using resonant dips in the transmission spectrum.…”