Research On Deflection Control Of Light Field Based On Transformation Optics And Absolute Instruments

When light propagates between different materials,the propagation direction will be changed due to the sudden change of interface refractive index,but the deflection is often sharp,and the deflection will also be limited by materials.In order to control the deflection of light arbitrarily,the scientists put forward the idea of transformation optics design,which uses the form invariance of Maxwell equations in coordinate transformation to design the required refractive index distribution of dielectric materials.However,the optical field deflection control devices designed in this way often have singularities(where the refractive index is infinite or zero),which can conveniently fabricated by eliminating it.Absolute instrument is one of the typical devices of light field deflection control,which has aberration free imaging characteristics and has important applications in radar detection and optical imaging.The Eaton lens can control the deflection of parallel rays by 180 degrees.However,the deflection angle is too single,and the free deflection control of the light field makes the generalized Eaton lens with more angles needed in practice.We study the light field control based on transformation optics and absolute instruments.Firstly,the singularity of material is eliminated,and the equivalence of inhomogeneity and anisotropy is verified;Secondly,the perfect double virtual image characteristics of the generalized Eaton lens with multi angle regulation are extended;Finally,a number of generalized Eaton lenses are used to form an optical pulley for multi angle deflection design.The thesis has the following main contents:(1)Based on conformal transformation optics,a special transformation function is used to eliminate the optical singularity in non-uniform isotropic materials,and the equivalent relationship between them and homogeneous anisotropic materials is established.The simulation results show that the deflection control is equivalent in geometry and wave optics after eliminating the singularity,and the light propagation outside the transform region is maintained.On this basis,the beam splitter whose deflection angle depends on the dielectric constant and permeability of the material is designed;(2)Based on the classical theory of Luneburg R.K.,the implicit expression of the refractive index distribution of the generalized Eaton lens which can deflect light at any angle is derived.It is found that only 90,180,300,360,540,900,1260 degree-Eaton lenses have analytic refractive index distribution.It is the first time to find that there are two perfect virtual imagings in the generalized Eaton lens,which are clearly verified by Dr.TIM software;(3)The photonic crystal is composed of generalized Eaton lens.Combined with the phenomenon different from geometrical optics in wave optics,the influence of different deflection angles on the band structure of photonic crystal with generalized Eaton lens is explored;Several generalized Eaton lenses are combined to construct an optical pulley to realize the deflection control design of multi angle light field on the chip,and the corresponding geodesic lens is transformed to provide ideas for chip integration.