摘要:
A coherent confocal microscope and methods for measuring elements of the non-linear susceptibility of a nanoparticle, including, more particularly, all of the elements of the second-order susceptibility tensor of a single nanoparticle under permutation and Kleinman symmetry. Using a high numerical aperture lens, two-dimensional scanning and a vector beam shaper, the second-order nonlinear susceptibility is derived from a single confocal image. A forward model for the problem is presented and a computationally efficient data processing method robustly solves the inverse problem.
摘要:
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.
摘要:
An intraoperative probe and a system for optically imaging a surgically significant volume of tissue or other scattering medium. An illumination source generates an illuminating beam that is conveyed to the vicinity of the tissue and a beam splitter, that may be no more than an optical phase reference, splits the illuminating beam into a sample beam along a sample beam path and a reference beam along a reference beam path. A scanning mechanism scans a portion of the sample beam across a section of the scattering medium, while a detector detects return beams from both the reference beam path and the sample beam path and generates an interference signal. A processor computationally moves an effective focus of the sample beam without physical variation of focus of the sample beam. The probe may have a sterilizable fairing that may be detachable.
摘要:
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.
摘要:
An intraoperative probe and a system for optically imaging a surgically significant volume of tissue or other scattering medium. An illumination source generates an illuminating beam that is conveyed to the vicinity of the tissue and a beam splitter, that may be no more than an optical phase reference, splits the illuminating beam into a sample beam along a sample beam path and a reference beam along a reference beam path. A scanning mechanism scans a portion of the sample beam across a section of the scattering medium, while a detector detects return beams from both the reference beam path and the sample beam path and generates an interference signal. A processor computationally moves an effective focus of the sample beam without physical variation of focus of the sample beam. The probe may have a sterilizable fairing that may be detachable.
摘要:
Methods for correcting for aberrations in the image or three-dimensional reconstruction of a sampled region obtained by broadband interferometry. The sampled region is illuminated with a broadband beam of light, and light returned from the sample is detected, along with a reference beam, in order to derive an interference signal for pixels of a volume spanned by wavenumber and axes transverse to the beam propagation direction. An optimization procedure is performed with respect to a specified criterion so as to obtain an aberration-corrected image of at least one plane of the sampled region, either in a plane-specific manner or in a space-invariant manner throughout the sampled region. A filter function, which may be derived from the interference signal attendant to irradiating a sparsely distributed plurality of point scatterers, or otherwise, corrects for a detected aberrated point spread function. Methods of the present invention may be used for aberration correction in reading information from an optical data storage medium.
摘要:
A coherent confocal microscope and methods for measuring elements of the non-linear susceptibility of a nanoparticle, including, more particularly, all of the elements of the second-order susceptibility tensor of a single nanoparticle under permutation and Kleinman symmetry. Using a high numerical aperture lens, two-dimensional scanning and a vector beam shaper, the second-order nonlinear susceptibility is derived from a single confocal image. A forward model for the problem is presented and a computationally efficient data processing method robustly solves the inverse problem.
摘要:
A coherent confocal microscope for fully characterizing the elastic scattering properties of a nanoparticle as a function of wavelength. Using a high numerical aperture lens, two-dimensional scanning and a simple vector beam shaper, the rank-2 polarizability tensor is estimated from a single confocal image. A computationally efficient data processing method is described and numerical simulations show that this algorithm is robust to noise and uncertainty in the focal plane position. The measurement of the polarizability removes the need for a priori assumptions regarding the nanoparticle shape.
摘要:
A near-field microscope using one or more diffractive elements placed in the near-field of an object to be imaged. A diffractive covers the entire object, thus signal may thereby be gathered from the entire object, and advantageously increase the signal-to-noise ratio of the resulting image, as well as greatly improve the acquisition speed. Near-field microscopy overcomes the limitation of conventional microscopy in that subwavelength and nanometer-scale features can be imaged and measured without contact.
摘要:
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.