%0 Journal Article %T In-Line Fiber Optic Interferometric Sensors in Single-Mode Fibers %A Tao Zhu %A Di Wu %A Min Liu %A De-Wen Duan %J Sensors %D 2012 %I MDPI AG %R 10.3390/s120810430 %X In-line fiber optic interferometers have attracted intensive attention for their potential sensing applications in refractive index, temperature, pressure and strain measurement, etc. Typical in-line fiber-optic interferometers are of two types: Fabry-Perot interferometers and core-cladding-mode interferometers. It¡¯s known that the in-line fiber optic interferometers based on single-mode fibers can exhibit compact structures, easy fabrication and low cost. In this paper, we review two kinds of typical in-line fiber optic interferometers formed in single-mode fibers fabricated with different post-processing techniques. Also, some recently reported specific technologies for fabricating such fiber optic interferometers are presented. %K in-line fiber-optic sensor %K Fabry-Perot interferometer %K core-cladding-mode interferometer %K Mach-Zehnder Interferometer %K Michelson interferometer %U http://www.mdpi.com/1424-8220/12/8/10430