Abstract:
Optical imaging of an object utilizes a plurality of amplitude modulated light rays propagating through the object, either sequentially or simultaneously, for detection by a single photodetector. The light rays may propagate geometrically (i.e., directly) or diffusively. Each of the rays is encoded with a different phase to provide sufficient information for decoding the light intensity detected by the photodetector. The rays may be applied simultaneously in an array, in which case different carrier frequencies as well as different phases are applied to the different rays by any of a number of modulators. Alternatively, the rays may be individually applied to the object in a sequence of phase encoded rays. In either case, the single photodetector receives sufficient information to image each of the voxels of interest in the object being imaged. Information may be obtained for different voxels selected for imaging without mechanical scanning.
Abstract:
Imaging of a turbid object utilizes interference among the modulation wavefronts (24) of a plurality of modulated light rays (22) propagating through the object by diffusion and having predetermined phases relative to one another. A computer controlled phase and amplitude selecting device, such as a zone plate (34) is used to modulate light rays at appropriate phases in order to obtain constructive interference only at a predetermined portion of the object, including one or more preselected voxels (26). The rays reflected from (or diffusively transmitted through) the predetermined portion are received simultaneously at a detector (16) thus providing simultaneously all the data necessary to describe or image the portion. A single detector (16) element may be used to detect the scattered reflected or transmitted light from the portion and to generate a signal representing the amplitude and phase characteristics for the modulation wavefront, thereby to provide absorption (and other) characteristics descriptive of the portion.
Abstract:
Disclosed are systems and methods for characterizing a nonlinear propagation environment by numerically propagating a measured output waveform resulting from a known input waveform. The numerical propagation reconstructs the input waveform, and in the process, the nonlinear environment is characterized. In certain embodiments, knowledge of the characterized nonlinear environment facilitates determination of an unknown input based on a measured output. Similarly, knowledge of the characterized nonlinear environment also facilitates formation of a desired output based on a configurable input. In both situations, the input thus characterized and the output thus obtained include features that would normally be lost in linear propagations. Such features can include evanescent waves and peripheral waves, such that an image thus obtained are inherently wide-angle, farfield form of microscopy.
Abstract:
A method of determining refractive index values of a sample in three spatial dimensions, the method including accessing, by a computing device, phase data representing sets of spatial phase information of the sample, wherein the sets of spatial phase information correspond to two-dimensional (2D) projections of the sample from at least partially coherent radiation; processing, by a computing device, the phase data to generate frequency-domain data representing each set of spatial phase information mapped to a corresponding set of frequency-domain values on a spherical cap surface in the frequency domain to compensate for three-dimensional (3D) diffraction of the radiation from the sample; combining, by a computing device processing the frequency-domain data, the mapped sets of frequency-domain values to generate a combined set of frequency-domain values in which the spherical cap surfaces are mutually aligned; and processing, by a computing device, the combined set of frequency-domain values to generate refractive index data representing the refractive index values of the sample in the three spatial dimensions.
Abstract:
Bei einem Verfahren zum Ermitteln einer Angabe über eine Brechzahl im Inneren mindestens eines Teils einer Probe (3) werden folgendes Schritte ausgeführt: a) unter dem Teil der Probe (3) wird eine Referenzfläche (3.2; 4) mit vorbekannter Oberflächenform vorgesehen, b) mit optischer Mikroskopie wird der Teil der Probe (3) für eine Vielzahl von Fokusebenen abgebildet, wobei die Abbildung von einer Seite der Probe her erfolgt, die der Referenzfläche (3.2; 4) gegenüber liegt, c) aus den Abbildungen wird ein Schnitt-Bild (8) oder ein 3D-Bild der Probe enthaltend ein Bild der Referenzfläche (8.2) erzeugt, d) Abweichungen zwischen dem Bild der Referenzfläche (8.2) und der vorbekannten Oberflächenform werden ermittelt, e) auf Basis der Abweichungen wird die Angabe über die Brechzahl im Inneren des Teils der Probe (3) ermittelt.
Abstract:
Disclosed is a method for determining an phase spectrum ?(?) of the complex spectral transfer function H(?) of a medium. In some embodiments, the method is applied for detecting or imaging an object screened by scattering medium or for determining a refractive index spectrum of a material.