ABSTRACT
This chapter presents an overview of the possibilities of implementing optical fiber as substrate for applications in environmental monitoring and biomedical applications to incorporate its real-time monitoring capability in the sensor-devising area. In an optical fiber, light is transmitted by means of total internal reflections. The angle of acceptance of the fiber is related to its numerical aperture. In U-shaped regime, the number of reflections occurring at the core-medium interface and the evanescent field penetration increases from that of a straight probe. Different applications of fiber such as sensing and communications require different number of modes propagating and hence a different fiber too. The linear response of the sensor is considered to be the best performing sensors, since it provides its maximum sensitivity for the complete range of operation. The lowest concentration of the target molecule in a solution that is detected by means of an analytical method is generally termed as the limit of detection.
