Development And Application Of Fiber Optic Fluorescence Sensor System Based On Linear CCD

As the main primary producers in the oceans, marine phytoplankton provides about 90 to 95 percent of marine primary production. Monitoring types and quantities of phytoplankton is a routine basic work in marine scientific research. The traditional methods of monitoring are microscope count method and standard precipitation count method, which needs consuming time and requires the staff with high professional quality. In addition, the measurement results using the traditional methods can not represent the concentration of large algae waters,depict its distribution, and meet the statistical analysis of a large number of samples because of the large randomness.Due to high sensitivity properties and multi-channel characteristics, low noise detection and signal synchronization determination, CCD can achieve "full spectrum" measured. So in the project system fiber optic fluorescence biosensor uses CCD detector technology. CCD have low illumination device and good linear ratio, which can improve spectrum efficiency and anti-jamming capability of fiber-optic system and reduce the cost of the system. With the unique advantages fluorescent fiber sensor can be applied in many ways, especially in extreme environments and conditions.Fluorescence monitoring seaweed state mainly measure fluorescence excitation spectrum and fluorescence spectrum of seaweed under the excitation light, analysis on Marine algae qualitatively and quantitatively depending on the intensity and the shape, and provide the basis for understanding of Marine ecological structure. This paper analyzes the characteristics of phytoplankton and seaweed fluorescence. In this paper,bioluminescence for optical fiber sensor principle, structure and characteristics are in detail described, and the optical fiber biological fluorescent sensor system is designed.In this article fiber optic fluorescence biosensor system designed consists of light source system, spectral detection systems, optical fiber transmission systems and data processing system. As a background light using 840 nm LED light source can effectively acquire effective information of bias light, so that subsequent signal processing work easier. Due to small size, light weight, high reliability, long life, bright enough and the simple power supply compatible with the characteristics of optical fiber, a blue light-emitting LED with peak wavelength of 450 nm is used for the excitation light source,which is ease to be integrated into a simple lightweight underwater probe with the high cost so as to effectively reduce the system cost. Due to high sensitivity, low detection noise and signal synchronization determination, dual-channel linear CCD detector is used as spectrum detector, which can achieve “full spectrum” measured. And the illumination gets good linearity, which can improve spectral efficiency and interference resistance of optical fiber transmission system. Using all-fiber optical structure facilitates rapid detection in the marine conditions.Experimental study on the chlorophyll fluorescence spectrum determination, single phytoplankton fluorescence measurement, and the measurement and calibration of the phytoplankton solution.Experiments show that the fiber-optic fluorescence biosensor system utilizes fluorescence excitation spectra of phytoplankton for classification and recognition, which gets rapid detection, and so that it can be used for live-line measurement. In the future we need improving the hardware and software systems and increasing the number and accuracy of phytoplankton classification and identification for the engineering and commercialization of laboratory prototype, which provides new techniques for water quality monitoring and other marine applications.