Research On Magneto-controllability Goos-H(?)nchen Shift On Ferrofluids

The shift of Goos-H(?)nchen(GH) is a typical optic phenomenon, which has importantapplications in optoelectronic devices, and has been one of the hot issues in the photonicsfield. GH shift in most cases is not tunable, but the adjustable of the GH shift in theapplication of the optical device is very necessary. The ferromagnetic fluid having bothmagnetic and fluidity is a special kind of new functional materials. The suspendednano-particles of this material are easily controlled by the external applied magnetic field,thereby the viscosity and structural properties of this material can be altered significantly,therefore we can adjust the environment state, change the parameters of the ferrofluidmaterials to achieve the purpose of control GH shift. On the other hand, with the emergencyand rapid development of the negative index materials, it was found that the GH shifts can benegative at the interface of both positive and negative index materials. In this paper, throughusing negative index material’s basic theories and the innovative new features of theferromagnetic fluid, we can achieve the result of control GH shift’s peak value, the peakposition and the size of its bandwidth by controlling the strength of the external appliedmagnetic field or changing the structure parameters of the medium. Especially, it provides asimple and feasible method to obtain the giant negative GH shift. The main research worksare summarized as follows:Firstly, explore the enhanced effect of the GH shift, to clarify the methods of obtaininggiant GH shift and the influence of dielectric loss on the GH shift, by analyses thecharacteristics of the GH shift, revealing the conditions of the medium showing the dielectricand metal behavior, respectively.Secondly, using the stationary phase method and energy flux method, combined with thegeometrical optics fundamental theorem, the theoretical arithmetic of GH shift is derivedfrom the principle of superposition of plane waves, by analyzing obtained the relationshipsbetween the various parameters affecting the GH shift, cleared about the contributions ofvarious factors on the reflection coefficient, transmission coefficient and GH shift.Lastly, derived that when the incident light or the probe wave incident on the surface ofthe ferrofluid or the cavity containing of ferrofluid, the influence relationships between thereflective, transmissive coefficients and the GH shift. Through simulating the changesituations of the GH shift under the external applied field, access to the main controllingmethods of GH shift in the ferrofluid, including the incident angle、the volume factor、the applied magnetic field and the shell parameter and so on, and has been cleared about theregulation effects of these factors on the GH shift.