Goal of nanoscale optical imaging gets boost with new hyperlens
Date: 26.3.2007
Scientists at the University of California, Berkeley, have developed a "hyperlens" that brings them one major step closer to the goal of nanoscale optical imaging.
The new hyperlens, described in the Feb. 23 issue of the journal Science, is capable of projecting a magnified image of a pair of nanowires spaced 150 nanometers apart onto a plane up to a meter away.
Currently, to capture details down to a few nanometers, scientists must use scanning electron or atomic force microscopes, which create images by scanning objects point by point. Scanning electron microscopes can take up to several minutes to get an image. Because the object must remain immobile and in a vacuum during this process, imaging is restricted to non-living samples.
Optical microscopes, in contrast, can snap an entire frame of an image in a single shot. They are commonly used in biological laboratories to study living cells, as well as in the high-tech industry to create integrated circuits, or in telecommunications. But the ability to resolve nanometer-level detail in optical imaging has been constrained by the so called "diffraction limit," a fundamental limit in optics related to the type of light waves emitted from an object.
Propagating waves can travel far and be collected by an optical lens, including the human eye, to form an image. Evanescent waves contain far greater detail and resolution of an object, but they decay too quickly for conventional lenses to capture them.
"Capturing the information carried by the evanescent waves is the Holy Grail of optical imaging," said Xiang Zhang, UC Berkeley professor of mechanical engineering and principal investigator of the study. "The hyperlens shows a new way to beat the diffraction limit, which would allow biologists to not only see a cell's nucleus and other smaller components, but to study the movement and behavior of individual molecules in living cells in real time. In technology, this could eventually lead to higher density integrated circuits and DVDs."...
Whole article: "www.physorg.com":[ http://www.physorg.com/news93795132.html]
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