• Number 300  |
• November 23, 2009

A soundwave hyperlens boosts sonar and ultrasound eightfold

The world’s first acoustic hyperlens, created by Xiang Zhang and his colleagues at DOE’s Lawrence Berkeley National Laboratory, provides an eightfold boost in the magnification power of sound-based imaging technologies. Conventional acoustic imaging is limited by the length of the sound wave, but the Berkeley Lab researchers overcome this diffraction limit using engineered wave dispersion surfaces. The hyperlens resolves details smaller than one-sixth the length of the waves themselves, bringing into view much smaller objects and features than can be detected using today’s technologies. The key is the capture of information contained in evanescent waves, which are usually confined to the vicinity of the source and decay too quickly to be captured, but carry far more details and higher resolution than propagating waves. Yet if evanescent waves carrying information about subwavelength features are gradually converted into propagating waves, the result is broad-band, low-loss imaging with large magnification.

[Lynn Yarris, 510.486.5375,
lcyarris@lbl.gov]