Molecular scale imaging with a multilayer superlens: (Pratik Chaturvedi; Nicholas Fang)

Recent theory by Pendry suggested a thin negative index film should function as a “superlens”, providing image detail with resolution beyond the diffraction limit—a limitation to which all positive index optics are subject. It has been demonstrated experimentally that a silver superlens allows to resolve features well below the working wavelength. Resolution as high as 60 nanometer (λ/6) half-pitch has been achieved.

            In this project, we explore the possibility of further refining the image resolution using a multilayer superlens. Using a stable transfer matrix scheme, our numerical calculations show an ultimate imaging resolution of λ/28. This is made possible using alternating stacks of alumina (Al₂O₃) and silver (Ag) layers to enhance a broad spectrum of evanescent waves via surface plasmon modes. With optimized design of multilayer superlens, our study indicates the feasibility of resolving features of 14nm and below. Preliminary experiments are ongoing to demonstrate the molecular scale imaging resolution. The development of potential low-loss and high resolution superlens opens the door to exciting applications in nanoscale optical metrology and nanomanufacturing.