Application Research Of Symmetrical Metal Cladding Waveguide

Based on the attenuated total reflection (ATR) effect of symmetrical metal cladding waveguide, measurement technique of the displacement and the wavelength monitoring method have been proposed. The effect due to waveguide nonparallelism on the ATR spectra and on the sensitivity of sensors based on symmetrical metal cladding waveguide has been analyzed.In the visible and near infra-red spectra, the real part of the permittivity of the metal is minus and its absolute value is much larger than that of the image part, therefore, it is easy to demonstrate ATR effect. By the prism coupling method and the free space coupling method, guided wave can be excited in a symmetrical metal cladding waveguide. With the thickness of the guiding layer being wide enough, the ultrahigh-order modes of the symmetrical metal cladding waveguide, which are considered to be very sensitive to the parameters of the guiding layer, can serve as a probe to the measurement of physical, chemical, and biological quantities.Owing to the high sensitivity of the ultrahigh order modes to waveguide parameters in symmetrical metal cladding waveguide, a new method of displacement detection and a wavelength monitoring technique have been proposed. In the proposed methods, the intensity of the reflected light, instead of the resonant angle, is used to measure the detected quantity, which is different from that in previous works. The...