pH Value Detection with CLPFG Sensor
Detection of pH value plays an important role in many fields; the precise measurement of pH value is very useful in Living systems, Chemistry and Biochemistry. The purpose of this paper is to measure pH value in solution by using Corrugated Long Period Fiber Grating (CLPFG). The CLPFG element is highly sensitive to refractive index changes, and with appropriate design geometry; a variety of target molecules can then be detected. Optical fiber Corrugated Long Period Gratings are designed to act as spectral loss elements that couple with a discrete wavelength out of the optical fiber as a function of the surrounding refractive index. By applying special coating that change refractive index with absorption of target molecules to the CLPFG surface, it became a transducer for chemical measurement. In this paper, it has shown the incorporation of Polyvinyl Alcohol and Polycyclic Acid (PVA-PAA) with Corrugated Long Period Gratings for the development of a fiber optic-based pH sensor with the detection of pH range from 3 to 6. Optical fiber-based pH sensors offer numerous advantages in wastewater monitoring, remote blood diagnostics, bioremediation, as well as chemical and food processing.
C. C. Chiang et al., "pH Value Detection with CLPFG Sensor", Applied Mechanics and Materials, Vols. 284-287, pp. 2157-2161, 2013