Study On The Ultraviolet Metamaterial Properties Of One Dimensional Periodic Optical Thin Films

In the latest decade, the research on metamaterial has been sprouting our all over the world, becoming one of the hottest research topics to date. Metamaterial is a kind of artificial compound material that doesn’t exist in nature. They have the special capability to change the transportation of electromagnetic wave, with effect such as negative refraction, supper resolution(breaking the diffraction limit), planar focusing, etc. Those fancy properties have never been envisioned in traditional materials. Therefore, the birth of metamaterial has raised the huge research interests of people.Metamaterial is fabricated by combining materials with different optical properties through modern material micro-processing techniques. Because the feature size of periodic variation of materials with different property is far smaller than the wavelength to which the metamaterial is applied, metamaterial behave like a bulk material with continuous optical property. In this regard, people have developed theories such as effective medium theory(EMT), which to an extent satisfactorily explained the unique permeability and permittivity of metamaterials. Because the feature size of periodicity in metamaterial should be far smaller than the wavelength, it places a stringent requirement on fabrication techniques for people. The shorter the wavelength, the smaller the feature size of metamaterial, the harder the fabrication process. To date, metamaterials for microwave, infrared, and even visible light have been realized in lab. However, as the electric industry has been pursuing smaller and smaller feature size and the development of integrated circuit and micro-electrical-mechanical system, people desire metamaterial to manipulate ultraviolet(UV) and even deep UV light, to realize techniques such as deep UV photolithography. However, fabricating metamaterials for such short wavelength faces even severe problem.In this dissertation, the metamaterial for UV and deep UV light have been studied. An one dimensional periodic multilayer structure has been proposed, which can be readily fabricated by the mature thin film deposition techniques, partially solving the problem for making two or three dimensional metamaterials. According to EMT, a one dimensional periodic Ag/Si O2 multilayer structure has been proposed and negative refraction has been realized by this structure from 326 nm to 342 nm. By theoretical analysis and simulation, its super-resolution imaging and focusing properties have been demonstrated. In addition, a one dimensional periodic Al/Al2O3 multilayer structure has been proposed by transmission matrix method(TMD), whose epsilon can be tuned to near zero, i.e. the so called epsilon near zero(ENZ) metamaterial. By changing the filling ratio of metal or the thickness of periodic element, the ENZ wavelength can be continuously tuned from 140 nm to 240 nm. By theoretical analysis and simulation, the features of directional emission, phase shaping and electric field enhancement of ENZ metamaterial have been demonstrated, and a method to realize planar focusing by ENZ metamaterial has been proposed.