Research Of Phytoplankton Detection Based On Hollow-Core Metal-Cladding Waveguide

The dissertation discussed the dielectric waveguide based on the basic theory of optical waveguide, and derived the dispersion equation and various optical characteristic of the dielectric slab waveguide by Maxwell's equations and the boundary conditions. Besides, the dissertation discussed the properties of hollow metal cladding waveguide, and analyzed the properties when they are used as sensor,and then it focused on the sensitivity of hollow metal cladding waveguide and the sensor device based on the high sensitivity.Because the upper and lower metal of the waveguide are precious metals usually,such as gold or silver, and the imaginary part is a negativity which has a large absolute value. So, the scope of the effective refractive index of the waveguide is large. We placed the sample in the test chamber. By taking use of software, we got the ATR spectra of hollow metal cladding waveguide, and then obtained the changing concentration in detection chamber. We found that, ATR spectra changes with the changing of the refractive index and the refractive changes with the various matters.Besides, as a plural form, the real part of the dielectric constant presents the intrinsic material loss, and the imaginary radiation loss. And in the ATR spectra, the coupling angle's horizontal moving represents the real part changing, and the lowest point's vertical moving of attenuated total reflection peak represents the imaginary changing.Ultra-order mode is resonant wave whice is a very sensitive to the changing environment, especially, to the refractive index and extinction coefficient of the environment. Besides, both the refractive index and extinction coefficient have a close relationship with the concentration of the substance, and both them change with the concentration of the substance changing. And in the hollow metal cladding waveguide,we can get ultra-order modes by using free space coupling technique. So it is obvious that the sensor based on the waveguide and ultra-order mode have an obvious advantage.Because the absorption peak position of attenuated total reflection of ultra-order modes andminR correspond to the refractive index and extinction coefficient directly.So, we can measure the concentration of the solution of phytoplankton accurately based on these dates. Besides, it not only does not need complex solid phase coupling technology and large equipment, but also has a very high sensitivity. And has a certainapplication in the field of food safety, environment protection and medical.