Highly Sensitive Fiber Optic Sensors based on Smart Tapered Fiber Interferometers

• Main Authors: Chia-Ming Li, 李家銘
• Other Authors: Cheng-Ling Lee
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/he8848

碩士 === 國立聯合大學 === 光電工程學系碩士班 === 101 === We have developed two kinds of highly sensitive tapered fiber interferometers (TFI) sensing devices that have smart configurations and high sensitivity for parametric sensing applications. The first fiber sensor demonstrates a novel, directional and sensitive fiber anemometer based on tapered fiber Michelson interferometer configuration. The proposed anemometers based on an anisotropic flat-clad tapered fiber Michelson interferometer enables sensing the direction and magnitude of flowing air (wind) simultaneously. Wavelength shifts and fringes visibility of the measured interference fringes are correlated with the magnitude as well as the direction of the wind. Experimental results show that the proposed directional anemometer can simultaneously and effectively indicate the direction, and sensitively measure the magnitude of wind. Another tapered fiber sensor is based on a fiber Mach-Zehnder interferometer (FMZI) by cascading two fiber tapers. The FMZI can be as a twist fiber sensor to achieve a highly sensitive and in-line sensing. Spectral sensitivity of the proposed sensor strongly depends on taper waist and thinner waist possesses higher sensitivity. Experimental results show that wavelength shifts and spectral loss of the interference fringes depends on the twist angles.