Journal Club Oct 17 10.30am

Sub–Diffraction-Limited Optical Imaging with a Silver Superlens
Nicholas Fang, Hyesog Lee, Cheng Sun, Xiang Zhang

Science, Vol. 308, 534-537 (2005)

Recent theory has predicted a superlens that is capable of producing sub–
diffraction-limited images. This superlens would allow the recovery of evanescent
waves in an image via the excitation of surface plasmons. Using silver as a natural
optical superlens, we demonstrated sub–diffraction-limited imaging with 60-
nanometer half-pitch resolution, or one-sixth of the illumination wavelength. By
proper design of the working wavelength and the thickness of silver that allows
access to a broad spectrum of subwavelength features, we also showed that
arbitrary nanostructures can be imaged with good fidelity. The optical superlens
promises exciting avenues to nanoscale optical imaging and ultrasmall optoelectronic
devices.