A Method of the Detection of Marine Pollution Based on the Measurement of Refractive Index

Abstract

For marine water pollution problems, According to the phenomenon that the refractive index of the seawater will change after been polluted .we designed a new fiber optical sensor, and completed a marine pollution monitoring automatic warning system with the sensor. One S (single mode)-M (multimode)-S-M-S structural optical fiber sensor based on the theory of M-Z Interference was made. Due to de refractive index of the fiber cladding will be affected by the environmental solution. We can determine the relationship between the movement of interference spectrum and the refractive index of the solution. With a center wavelength of 1553nm fiber Bragg grating and a coupler to obtain the change of the intensity of the light, then though the specific circuit, we can change the light intensity into the voltage values. Then enter the computer through the acquisition card, real-time reporting of environmental refractive index size, and according to the software set threshold alarms. The refractive index in the range of 1.330-1.390, the system of measurement error is less than 1%.