Characterization of Mach-Zehnder interferometer-based photonic crystal fiber sensors

摘要

We propose a new design of Mach-Zehnder interferometers (MZI) structure assembled with two arms composed of 400nm-diameter-hole-modifted silica photonic crystal fibers (PCFs) and immersed in solvent solution. The proposed design is found to enhance considerably the sensitivity. A highly-sensitive versatile interferometry technique is used to determine the phase shift from both arms and consequently the specimen's information can be retrieved. The proposed sensor was first tested when considering the specimen to be analyzed with different concentrations for a probing light of 325 nm. The sensitivity of detecting the benzene solutions in water reaches 9 rad/μm which is much higher compared to what was achieved in photonic nanowires. Then, the detection of corn oil into olive oil is achieved with high sensitivity of 14.7 rad/μm demonstrating that the sensor is capable of detecting a RI variation of 4×10~(-7) in only 1-mm sensitive-area-length. Thus, the proposed MZI-based PCF-sensor shows to be very attractive for compact, flexible and high sensitive biochemical sensing.