Fiber-optic evanescent wave sensor with a segmented structure.

A segmented structure optic fiber sensor is proposed and demonstrated; it is based on evanescent wave absorption theory. The waveguide modes of the segmented structure are simulated and analyzed by using the beam propagation method, which shows the high-order modes are excited repeatedly at the first transition of each segmented region. The effect of the number of segments and the core diameters on the sensitivity of the sensors is investigated experimentally.