Washington University

University of Illinois

John Carl Schotland

Paul Scott Carney

Jin Sun

Vadim Arkadievich Markel

Brynmor J Davis

Rainer Hillenbrand

A method and computer program product for imaging an object are disclosed. The object is illuminated with an electromagnetic wave, characterized by a spectrum of illuminating wavevectors. Electromagnetic waves scattered by the object are detected, and are characterized by a spectrum of detected wavevectors. An aperture equal to or smaller than an instantaneous characterizing wavelength of the illuminating electromagnetic wave is disposed between the source and the detector. At least one of the illuminating and detected wavevectors is varied in magnitude to provide information regarding a scattering characteristic of the object. By applying a forward model of the aperture to derive a three-dimensional scattering model, a three-dimensional reconstruction of the object may be obtained by inverting a detected data function in terms of the forward model.

Spectral near-field optical tomography

An apparatus and methods for nanoscale optical tomography based on back-scattering mode near-field scanning optical microscopy with a volumetric scan of the probe. The back-scattered data collected by a volumetric scan of the probe contains three-dimensional structural information of the sample, which enables reconstruction of the dielectric sample without other mechanical movements of the instrument.

Nanoscale optical tomography based on volume-scanning near-field microscopy

A methodology and concomitant system for the reconstruction of an object from measurements of the transmitted intensity of scattered radiation effected by irradiating the object with a source of radiation. The measurements of the transmitted intensity are both spatially sampled and limited. The transmitted intensity is related to either the absorption coefficient or diffusion coefficient, or both, of the object by an integral operator. The image is directly reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the transmitted intensity of the scattered radiation. In a preferred embodiment, the data is measured using a paraxial arrangement composed on a single source and a small number of on-axis and off-axis detectors with the arrangement being moved over the measurement surface to measure the set of sampled and limited data.

System and method of image reconstruction for optical tomography with limited data

A method for the reconstruction of a tomographic image of an object from measurements of scattering data resulting from probing waves. The scattering data is related to a forward scattering operator by an integral operator. The tomographic image is reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the scattering data.

System and method for scanning near-field optical tomography

A methodology and concomitant system for three-dimensional near-field microscopy achieves subwavelength resolution of an object without retrieval of the optical phase. The features of this approach are three-fold: (i) the near-field phase problem is circumvented by employing measurements of the power extinguished from probe fields; (ii) the fields on which the power measurements are performed may be monitored far from the object and thus subwavelength resolution is obtained from far zone measurements; and (iii) by developing an analytic approach to the inverse problem in the form of an explicit inversion formula, an image reconstruction algorithm is produced which is strikingly robust in the presence of noise.

System and method for dual-beam internal reflection tomography

A methodology and concomitant system for three-dimensional near-field microscopy achieves subwavelength resolution of an object via total internal reflection. The features of this approach include: (i) the evanescent waves used for illumination encode on the scattered field the subwavelength structure of the scattering object&mdash;it is thus possible to obtain subwavelength resolved images of the sample as is done in other near-field techniques such as near-field scanning optical microscopy without the technical difficulties encountered with probe-sample interactions; and (ii) the results of the reconstruction are unambiguous in the sense that the relation between the scattered field and the three-dimensional structure of the sample, as described by the spatial dependence of the susceptibility, is made manifest.

Growing community of inventors

Ladue, MO, United States of America

John Carl Schotland