Emerging Application Mechanisms of Optical Fiber Sensors

Abstract

Optical fibers can be used as sensors to measure strain, temperature, pressure and other quantities by modifying a fiber so that the quantity to be measured modulates the intensity, phase, polarization, wavelength or transit time of light in the fiber. Sensors that vary the intensity of light are the simplest, since only a simple source and detector are required. A particularly useful feature of intrinsic fiber optic sensors is that they can, if required, provide distributed sensing over very large distances. Temperature can be measured by using a fiber that has evanescent loss that varies with temperature, or by analyzing the Rayleigh scattering, Raman scattering or the Brillouin Scattering in the optical fiber. Electrical voltage can be sensed by nonlinear optical effects in specially-doped fiber, which alter the polarization of light as a function of voltage or electric field. Angle measurement sensors can be based on the Sagnac effect. The establishment of sensor systems has elated recompenses such as measurement in flammable and explosive atmospheres, resistance to electrical noises, trimness, geometrical suppleness, measurement of slight sample volumes, remote sensing in unreachable sites or harsh atmospheres and multi-sensing. Biosensors are logical devices composed of a recognition component of biological origin and a physico-chemical transducer. Immobilization plays a foremost character in developing the biosensor by incorporating both the above mentioned mechanisms. In this paper, an analytical review of fiber optic sensors and biosensors towards real world applications for environmental and clinical monitoring have been reviewed.

Keywords: Sensor, Complete Cell Biosensor, Control of Biologicals, Tapered Optical Fiber, Optical Chemical Sensor, Chemical Equilibrium, Biosensors, Physico-Chemical Transducer, Environmental and Clinical Monitoring