This article proposes an optical fiber sensor based on a high-performance Mach-Zehnder interferometer (MZI), using a piece of no-core fiber (NCF) spliced at both ends with single-mode fibers. Two attuned NCF pieces were adjusted to the dimensions of 30 & micro;m and 60 & micro;m in diameters, with lengths of 3 cm and 5 cm, respectively, to amplify the coupling efficiency via the effect of multi-mode interference. This sensor exhibited good sensitivity to acetone vapor monitoring with approximately 4.8004 & times; 10-5 dB/ppm. It demonstrated a low detection limit (LOD) of 207 ppm and a low drift of about 0.01284 dBm with high stability and good repeatability.
