Abstract:
A system for analyzing optical cavity modes of at least one microcavity or at least one cluster of microcavities, comprises, an apparatus for sensing a change in the condition of or for analyzing the optical cavity modes by utilizing an optical interference of the optical cavity modes.
Abstract:
A Micro Electro-Mechanical System (MEMS) spectrometer architecture compensates for verticality and dispersion problems using balancing interfaces. A MEMS spectrometer/interferometer includes a beam splitter formed on a first surface of a first medium at an interface between the first medium and a second medium, a first mirror formed on a second surface of the first medium, a second mirror formed on a third surface of the first medium and balancing interfaces designed to minimize both a difference in tilt angles between the surfaces and a difference in phase errors between beams reflected from the first and second mirrors.
Abstract:
A method for determining a background noise level includes receiving interferogram data; determining at least one measure of interferogram quality; accumulating said received interferogram data; and generating a background noise level based on said interferogram data and at least one measure of interferogram quality.
Abstract:
The present invention provides apparatuses and methods for sample analysis, such as tissue analysis, that integrate high wavenumber (HW) Raman spectroscopy for chemical composition analysis and spectral-domain optical coherence tomography (SD-OCT) to provide depth and morphological information. Intravascular catheter embodiments and related vascular diagnostic methods are also provided.
Abstract:
A sensor and method for remotely determining a presence of a particular substance based on spectral data of the particular substance is disclosed. The sensor includes a sampling module configured to detect radiation from a particular substance using an interferometer, wherein the sampling module includes a control module that is configured to guide and measure spacing of samples taken by the sampling module; a focal plane module configured to detect and convert an interference pattern produced by the interferometer into a series of digital samples; a reference spectra modification module configured to modify reference spectra by modifying according to the measured spacing of samples and an instrument line shape of the sampling module; an estimation module configured to receive the converted series of digital samples and transform the non-uniformly spaced digital samples into frequency space using band centers determined from reference spectra as modified by the instrument line shape of the sampling module; a comparison module configured to compare the transformed digital samples against a database of known chemical signatures; and a determination module configured to determine the presence of the particular substance based on the results of the comparison.
Abstract:
Light is collected from a sample that is to be imaged, such as tissue or the like, and made to undergo self-interference, e.g., on a detector. An imaging system may include a low coherence light source arranged for illuminating the sample, and an interferometer arranged to receive the light collected from the sample and to pass it to a detector. The interferometer includes a beam divider that directs the radiation collected from the sample along two paths, phase-delaying one beam relative to another and then recombining the beams on a detector. A processor may be coordinated with the phase delay and in some embodiments with spatial scanning or detector array addresses, and operates on the signal from the detector to form a tomographic image of the sample illuminated tissue. By constructing an image based upon interference the interferometric signal from of the split and then recombined radiation collected from the sample signal, rather than interference of a source reference and a return signal, the invention is able to image with light naturally emitted by the sample. , or with wavelength-shifted, delayed or induced light signals of different types, allowing new modalities of diagnostic and other imaging of the sample and its structure. A processor generates one or more images of the structure being viewed, and may create images in registry from different (for example, close but separable) wavelengths. Some systems may operate without an illumination source or may apply other stimuli to evoke emission from the sample.
Abstract:
A method processes an optical image. The method includes providing a measured magnitude of the Fourier transform of a two-dimensional complex transmission function. The method further includes providing an estimated phase term of the Fourier transform of the two-dimensional complex transmission function. The method further includes multiplying the measured magnitude and the estimated phase term to generate an estimated Fourier transform of the two-dimensional complex transmission function. The method further includes calculating an inverse Fourier transform of the estimated Fourier transform, wherein the inverse Fourier transform is a spatial function. The method further includes calculating an estimated two-dimensional complex transmission function by applying at least one constraint to the inverse Fourier transform.
Abstract:
A surface shape measurement apparatus is configured to measure a surface shape of an object to be measured, and includes a beam splitter configured to split white light from a light source into two light beams, a pair of prisms each configured to increase an incident angle of each light beam that has been split by the beam splitter and directed to the object or a reference surface, each prism having an antireflection part that is formed at a period of a wavelength of the white light or smaller and has a moth-eye shape, a superimposition unit configured to superimpose object light from the object with reference light from the reference surface and has passed the second prism, and to generate white interference light, and a Lyot filter configured to discretely separate the white interference light for each of a plurality of wavelengths.
Abstract:
A Fourier-domain optical coherence tomography (OCT) imager is presented. An OCT imager according to the present invention can have an auto-alignment process. The auto-alignment process automatically adjusts at least one optical component of a spectrometer of the imager so that the spectrometer is aligned during an imaging session. In addition to the auto-alignment process, OCT spectra are normalized for background spectra and for noise characteristics in order to provide a more accurate and clear OCT image.