Theoretical Research On Electromagnetic Controllable Goos-H(?)nchen Shift

In 1947,F.Goos and H.Hanchen first proved that the actual reflection point away from the incident point has a distance with the experimental method when the total reflection occurs.We call this distance the Goos-H?nchen shift(GH shift).This is explained by the fact that the incident light is a non-ideal monochromatic plane wave.The incident light can be decomposed into different monochromatic plane wave components,and so those plane waves have different phase shift respectively in the reflection.Then a GH shift is formed.There are lots of methods to control GH shift,but the electromagnetic control method of GH shift has been studied in recent years.The combination of the electronic controlled GH shift and semiconductor provides a feasible way for the integration and miniaturization of optical devices base d on the GH shift effect.In addition,the method of electromagnetic control provides a convenient way to fine tune the optical sensor,which can reduce the requirements of some process for the manufacture of such sensors.In this paper,we studied the electronic and magnetic controlled GH shift and the application on it in the optical switch.The following several aspects of the work are carried out.(1)A study of the electronic controllability of GH shift in a structure of a symmetrical metal-cladding waveguide(SMCW)and a metal-insulator-semiconductor(MIS)configuration was undertaken.Firstly,a new method of voltage control for GH shift based on SMCW is introduced.The experimental results show that the range of the tunable GH shift is 0 to 720 ?m when the incident wavelength is 859.002 nm and the applied voltage range is 0 to 2000 volts.And then,the SMCW structure based on PMN-PT is introduced,which also can tune the GH shift.This structure has advantages of fast controlled speed and low working voltage in a few hundred volts.Based on the multi-layer structure of MIS,We proposed a scheme to manipulate the GH shift of a light beam reflected from the depletion-type device via external voltage bias.Our theoretical study shows that the huge GH shift can be obtained when the incident wavelength is 10 um and the applied voltage range is 0 to 12 volts.(2)A study of magnetic controllability of GH shift in the case of isotropic and anisotropic in the ferrofluids was performed.Buil t on the multi-layer structure Containing Colloidal Ferrofluids,we first carried out the study on the magnetic controllability of GH shift.Optical properties of the ferrofluids under a magnetic field can exhibit two different kinds of electromagnetic pro perties.The incident interface is perpendicular to the external magnetic field,which is characterized by the isotropic optical characteristics.The incident interface is parallel to the direction of the external magnetic field,and the ferrofluid exhibit s an anisotropy.The theoretical calculation shows that the GH shift in a cavity Containing Colloidal ferrofluids can be manipulated by an external magnetic field,and the GH shift of 700 times of the incident wavelength can be achieved.