Studies of Subwavelength Imaging and Focusing Using Metamaterials
|Keywords||Lithography Phase shift mask Hyperbolic lens Subwavelength imaging Focus Metamaterials|
With the rapid development of information technology, the modern high-tech development toward more sophisticated areas. Especially for high-end nano-optical imaging technology applications, such as optical lithography, confocal microscopy, high-density optical storage, nano laser processing, biological microscopic imaging and life sciences and other fields often need subwavelength (nanoscale ) resolving power. However, due to the presence of the diffraction limit of conventional optical imaging techniques has been unable to meet the actual requirements. Based subwavelength resolution imaging technology breakthrough of traditional diffractive optical limit - hyperbolic lens technology combined with super-lens technology, through the traditional technology to improve lithography resolution - phase shift mask technology (phase shift mask, PSM) proposed a super-resolution imaging system nanolithography. The theoretical analysis and numerical simulation results show that this system can significantly improve the resolution of the existing lithography. Meanwhile, based on a natural materials do not have the extraordinary physical properties, and its characteristics can be adjusted according to the need to artificially metamaterial designed horn condenser lens for focusing a subwavelength. This ability to work in a different wavelength focal spot can reach a few nanometers superlens has important potential application value. First, based on the phase shift mask and a hyperbolic lens analysis, a new nanometer lithography imaging system. Phase-shift mask can not only by increasing the phase shift to eliminate diffraction interference between the adjacent groove, the same time as the distance between the groove is very small, it can excite surface plasma waves at the interface of the mask and the lens, this along the metal between each of the grooves, the surface transfer of the wave will cause interference phenomenon. Phase shift angle by adjusting the phase shifter, and ultimately for the hyperbolic lens imaging provides clearer \Slab lens bending metal and dielectric layers alternately filled with hyperbolic dispersion characteristics, it is called the \It can not only transfer the transmission wave component, at the same time can be an effective transmission the prosperous loss wave, the final super-resolution imaging of achieve the breakthrough diffraction limit. By analyzing the imaging principle and characteristics of the imaging system, and compared with the traditional model, found that the imaging system is not only able to break the diffraction limit higher resolution graphics at the same time be able to achieve, such as the proportion of narrow imaging. This not only improves the resolution of nanolithography, while effectively reducing the feature size of the chip, improve integration, provide important theoretical basis for the rapid development of microelectronics technology, with a wide range of research applications. Secondly, with the unique properties of metamaterials and a coordinate transformation theory, in this paper, we have to design a novel focus hyperbolic lens, such a lens can not only by changing the dielectric constant of the filling medium to change its working wavelength. Meanwhile, to change the number of layers of the lens, we can get a different spot size and focal length. Such high focusing efficiency of the focused spot can reach a few nanometers high-performance super-lens, there will be a lot of applications space. The result, hyperbolic lens based on the phase-shift mask tablet nanolithography study and design of a new type of ultra-focusing lens, were able to break the diffraction limit to achieve subwavelength imaging or focusing. This will in nano-optical imaging technology, microfabrication technology and surface plasma the waveguide excitation has important theoretical value and application prospects.