ABSTRACT
This chapter describes various technologies for the fabrication of Fiber-Optic Fabry-Perot interferometer (FFPI) sensors. Novel fabrication techniques for fiber-optic sensors are very much in demand to create new functional sensors. The advancement in Femtosecond (fs)-laser technology has opened a new window of opportunity for precise fabrication of microdevices with true three-dimensional (3D) configurations. Focused ion beam (FIB) has been used in a number of fiber-based applications, including fabrication of long-period gratings, micromachining of fiber tips, and milling of side access holes in structured optical fibers. As a consequence of its applications in semiconductor technology, the FIB technique is mature and more flexible than fs-laser processing, and dual-beam instruments combining a scanning electron microscopic (SEM) and FIB are now commercially available. A light-emitting diode (LED) was used to illuminate the sample so that the micro Fabry-Perot interferometer (MFPI) sensor after ablation can be monitored in real time by using a charge-coupled device (CCD) camera attached to a phase-contrast optical microscope.
