No abstract

Abstract-The development, design, and evaluation of an intrinsic optical fiber pH sensor for low pH values (in the range of 0.5-6) based on fluorescence from a novel coumarin dye, which is covalently immobilized onto the end surface of an optical fiber is described. The sensor provides a rapid response (of approximately 25 s) over this pH range of 0.5-6.0, showing with very good stability over a period of several months. The sensor has also demonstrated insensitivity to ionic strength and excellent photostability through a series of laboratory tests.Index Terms-Optical fiber sensor, fluorescent sensor, pH sensor, coumarin dye.

No abstract

A long period grating (LPG)-based optical fiber sensor, coated with polyvinyl alcohol, has been developed for relative humidity (RH) measurement over the range from 33%RH to 97%RH, for which the grating response has been monitored. The fiber optic sensor using the LPG has been designed to monitor the change in resonance loss which is then related to the humidity measured through calibration of the sensor with a series of materials of known refractive index. Results on the calibration and use of the sensor are reported and considered in this work, in light of other gratingbased methods for humidity measurement.

No abstract