Optical fiber chemical sensor systems and devices

Abstract

Optical techniques for chemical analysis are well established. Actual sensors based on these techniques, as opposed to proposed systems described in the literature, are now attracting considerable attention because of their importance in applications such as environmental monitoring, biomedical sensing and industrial process control. In many instances these sensors exploit the specific advantages made available by optical fiber technology, as fiber optic chemical sensors (FOCS) can benefit from, for example, the geometric versatility, low attenuation and electrical noise immunity of optical fibers. In this chapter, the emphasis throughout is on the developments which have occurred to produce a series of FOCS systems and devices, although many of the methods described can be transferred, sometimes with considerable advantage, to planar waveguide configurations. Alternatively, they can operate successfully without the use of optical fibers at all through open air-path systems, an option which is often neglected in the general promotion of optical chemical sensors.