Magnifying Superlenses

+ See all authors and affiliations

Science  23 Mar 2007:
Vol. 315, Issue 5819, pp. 1633
DOI: 10.1126/science.315.5819.1633a
CREDIT: XIANG ZHANG/UC- BERKELEY

Although the spatial resolution of a conventional optical microscope is limited by diffraction to a value of the order of 200 nanometers, a “superlens” based on specially structured metamaterials designed to exhibit a negative refractive index could overcome this limitation. However, the planar superlenses demonstrated to date cannot provide magnification. Smolyaninov et al. (p. 1699) describe a magnifying superlens based on the propagation of surface-plasmon polaritons (SPP). The object to be imaged and magnified is placed inside the center region of their lens, a structure of concentric circles of a polymer deposited on a gold substrate. The light scatters off the object and creates SPPs in the gold film. With the structured lens designed properly, the SPPs propagate radially outward through the “lens” of concentric circles. The magnified image of the object can then be seen at the outermost circle with a conventional microscope. In Brevia, Liu et al. (p. 1686) have used curved nanoscale multilayers of silver and alumina to create a superlens that projects the image of an object onto a far-field surface, where it can be viewed with a conventional microscope.

Navigate This Article