ABSTRACT
This chapter introduces various microstructures of Fiber-Optic Fabry-Perot interferometers (FFPIs) and their corresponding advantages. It discusses several ways to classify FFPI sensors. First, in terms of fiber types, it includes FFPIs based on singlemode and multimode, as well as microstructured fibers and tapered or microfibers. Second, they can be classified into intrinsic, extrinsic, and hybrid FFPIs. Third, FFPI sensors can be classified in terms of Q factor or finesse. The performance of the intrinsic FFPI (IFFPI ) sensor based on FBG may degrade if there is a mismatch in the spectral profile of the weak fiber Bragg grating (FBG) pairs. In 1988, H. Taylor and coworkers proposed an IFFPI temperature sensor by introducing a pair of dielectric mirrors into the singlemode optical fiber. Radially asymmetric IFFPI structure often has a lateral offset fabricated by using the fusion splicing method. Chemical etching methods have been used for shaping the microstructure of optical fibers for a long time.
