Recently, the concept of superlensing has received considerable attention for its unique ability to produce images below the diffraction limit. The theoretical study has predicted a 'superlens' made of materials with negative permittivity and/or permeability, is capable of resolving features much smaller than the working wavelength and a near-perfect image can be obtained through the restoration of lost evanescent waves (Pendry 2000 Phys. Rev. Lett. 85 3966-9). We have already demonstrated that a 60 nm half-pitch object can indeed be resolved with λ0/6 resolution with the implementation of a silver superlens with λ0= 365 nm illumination wavelength, which is well below the diffraction limit (Fang et al 2005 Science 308 534-7). In order to further support the imaging ability of our silver superlens, a two-dimensional arbitrary object with 40 nm line width was also imaged (Fang et al 2005 Science 308 534-7). In this paper, we present experimental and theoretical investigations of optical superlensing through a thin silver slab. Experimental design and procedures as well as theoretical studies are presented in detail. In addition, a new superlens imaging result is presented which shows the image of a 50 nm half-pitch object at λ0/7 resolution.
ASJC Scopus subject areas
- Physics and Astronomy(all)