Far-field signature of sub-wavelength microscopic objects

Far-field optical hyperlens magnifying sub-diffraction-limited objects.

The diffraction limit of light, which is causd by the loss of evanescent waves in the far field that carry high spatial frequency information, limits the resolution of optical lenses to the order of the wavelength of light. We report experimental demonstration of the optical hyperlens for sub-diffraction-limited imaging in the far field. The device magnifies subwavelength objects by transformin...

Adiabatic far-field sub-diffraction imaging

The limited resolution of a conventional optical imaging system stems from the fact that the fine feature information of an object is carried by evanescent waves, which exponentially decays in space and thus cannot reach the imaging plane. We introduce here an adiabatic lens, which utilizes a geometrically conformal surface to mediate the interference of slowly decompressed electromagnetic wave...

Terahertz probe for spectroscopy of sub-wavelength objects.

A system of two probes is designed for terahertz (THz) time-domain spectroscopy of sub-wavelength size objects. A twin-needle probe confines broadband THz pulses spatially by means of surface plasmon waves to a sub-wavelength spot smaller than 10 microns. The confined pulses are detected within the near-field zone of the twin-needle probe by a sub-wavelength aperture probe. The system allows TH...

Far-field Source Signature Reconstruction Using Direct Arrival Data

Classifying Tracked Objects in Far-Field Video Surveillance

Automated visual perception of the real world by computers requires classification of observed physical objects into semantically meaningful categories (such as ‘car’ or ‘person’). We propose a partially-supervised learning framework for classification of moving objects—mostly vehicles and pedestrians—that are detected and tracked in a variety of far-field video sequences, captured by a static,...