1. Articles from Peter J. De Groot

    1-13 of 13

    1. Interferometry employing refractive index dispersion broadening of interference signals

      Explore uspto.gov Patents
      Interferometry employing refractive index dispersion broadening of interference signals

      An interferometry system includes: a light source, defining a coherence length, an interferometer configured to combine measurement and reference beams to form an output beam, where the interferometer includes a dispersion imbalance between measurement and reference paths large enough to produce a coherence envelope for the system having a width more than twice the coherence length; a phase modulation device configured to introduce a variable phase between the measurement and reference beams; a detector; imaging optics to direct the output beam to the detector and produce an image of the measurement surface; and an electronic processor electronically coupled to the ...

      Read Full Article
      Mentions: Zygo Peter J. De Groot

    2. Compensation of systematic effects in low coherence interferometry

      Explore uspto.gov Patents
      In general, in one aspect, the invention features a method that includes transforming interferometry data acquired for a test sample using a low coherence imaging interferometry system to a frequency domain and, at a plurality of frequencies in the frequency domain, reducing contributions to the transformed interferometry data due to imperfections in the imaging interferometry system thereby producing compensated interferometry data. The errors are reduced based on variations between interferometry data acquired using the low coherence imaging interferometry system for a calibration sample and model interferometry data corresponding to data acquired for the calibration sample using a model interferometry system.
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    3. Scanning interferometry for thin film thickness and surface measurements

      Explore uspto.gov NDE/NDT , Patents
      A method including: providing a low coherence scanning interferometry data for at least one spatial location of a sample having multiple interfaces, wherein the data is collected using a low coherence scanning interferometer having an illumination geometry and an illumination frequency spectrum, and wherein the data comprises a low coherence scanning interferometry signal having multiple regions of fringe contrast corresponding to the multiple interfaces; and determining a distance between at least one pair of interfaces based on a distance between the corresponding regions of fringe contrast and information about the illumination geometry.
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    4. Methods and systems for interferometric analysis of surfaces and related applications

      Explore uspto.gov NDE/NDT , Patents
      A method for determining a spatial property of an object includes obtaining a scanning low coherence interference signal from a measurement object that includes two or more interfaces. The scanning low coherence interference signal includes two or more overlapping low coherence interference signals, each of which results from a respective interface. Based on the low coherence interference signal, a spatial property of at least one of the interfaces is determined. In some cases, the determination is based on a subset of the low coherence interference signal rather than on the entirety of the signal. Alternatively, or in addition, the determination ...
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    5. Triangulation methods and systems for profiling surfaces through a thin film coating

      Explore uspto.gov NDE/NDT , Patents
      An optical system includes a photolithography system, a low coherence interferometer, and a detector. The photolithography system is configured to illuminate a portion of an object with a light pattern and has a reference surface. The low coherence interferometer has a reference optical path and a measurement optical path. Light that passes along the reference optical path reflects at least once from the reference surface and light that passes along the measurement optical path reflects at least once from the object. The detector is configured to detect a low coherence interference signal including light that has passed along the reference ...
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    6. Surface profiling using an interference pattern matching template

      Explore uspto.gov NDE/NDT , Patents
      A method for determining a spatial property of an object includes obtaining a scanning low coherence interference signal from a measurement object that includes two or more interfaces. The scanning low coherence interference signal includes two or more overlapping low coherence interference signals, each of which results from a respective interface. Based on the low coherence interference signal, a spatial property of at least one of the interfaces is determined. In some cases, the determination is based on a subset of the low coherence interference signal rather than on the entirety of the signal. Alternatively, or in addition, the determination ...
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    7. Low coherence grazing incidence interferometry for profiling and tilt sensing

      Explore uspto.gov NDE/NDT , Patents
      An optical system includes a photolithography system, a low coherence interferometer, and a detector. The photolithography system is configured to illuminate a portion of an object with a light pattern and has a reference surface. The low coherence interferometer has a reference optical path and a measurement optical path. Light that passes along the reference optical path reflects at least once from the reference surface and light that passes along the measurement optical path reflects at least once from the object. The detector is configured to detect a low coherence interference signal including light that has passed along the reference ...
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    8. Profiling complex surface structures using scanning interferometry

      Explore uspto.gov NDE/NDT , Patents
      A method including comparing information derivable from a scanning interferometry signal for a first surface location of a test object to information corresponding to multiple models of the test object, wherein the multiple models are parametrized by a series of characteristics for the test object. The information corresponding to the multiple models may include information about at least one amplitude component of a transform of a scanning interferometry signal corresponding to each of the models of the test object.
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    9. Profiling complex surface structures using height scanning interferometry

      Explore uspto.gov NDE/NDT , Patents
      A method including comparing information derivable from a scanning interferometry signal for a first surface location of a test object to information corresponding to multiple models of the test object, wherein the multiple models are parametrized by a series of characteristics for the test object. The derivable information being compared may relate to a shape of the scanning interferometry signal for the first surface location of the test object.
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    10. Interferometry method for ellipsometry, reflectometry, and scatterometry measurements, including characterization of thin film structures

      Explore uspto.gov NDE/NDT , Patents
      A method including: imaging test light emerging from a test object over a range of angles to interfere with reference light on a detector, wherein the test and reference light are derived from a common source; for each of the angles, simultaneously varying an optical path length difference from the source to the detector between interfering portions of the test and reference light at a rate that depends on the angle at which the test light emerges from the test object; and determining an angle-dependence of an optical property of the test object based on the interference between the test ...
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    11. Measurement of complex surface shapes using a spherical wavefront

      Explore uspto.gov NDE/NDT , Patents
      Conical surfaces (and other complex surface shapes) can be interferometrically characterized using a locally spherical measurement wavefront (e.g., spherical and aspherical wavefronts). In particular, complex surface shapes are measured relative to a measurement point datum. This is achieved by varying the radius of curvature of a virtual surface corresponding to a theoretical test surface that would reflect a measurement wavefront to produce a constant optical path length difference (e.g., zero OPD) between the measurement and reference wavefronts.
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    12. Interferometer having a coupled cavity geometry for use with an extended source

      Explore uspto.gov Patents
      In certain aspects, the invention features an interferometry system that utilizes coupled cavities (e.g., at least one remote cavity and a main cavity) and an extended light source. The remote cavity and the main cavity can have similar optical properties (e.g., similar numerical apertures (NA's)), allowing them to introduce offsetting, and therefore compensating, non-zero optical path differences (OPD's) between the measurement and reference beams without degrading interference fringe contrast due to source spatial coherence. In other words, for each non-zero OPD in the main cavity there exists a configuration of the remote cavity such that the ...
      Read Full Article
      Mentions: Zygo Peter J. De Groot

    13. Interferometric optical systems having simultaneously scanned optical path length and focus

      Explore uspto.gov Patents
      In certain aspects, the invention features scanning interferometry systems and methods that can scan an optical measurement surface over distances greater than a depth of focus of imaging optics in the interferometry system, while keeping an optical measurement surface in focus (i.e., maintaining an image of the optical measurement surface coincident with the detector). The optical measurement surface refers to a theoretical test surface in the path of test light in the interferometer that would reflect the test light to produce an optical path length difference (OPD) between it and reference light that is equal to a constant across ...
      Read Full Article
      Mentions: Zygo Peter J. De Groot
    1-13 of 13
  1. Search:

  2. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology

    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents

    3. Technology:

      Broadband Sources, Probes, Tunable Sources

    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks

  4. Topics in the News

    1. (13 articles) Peter J. De Groot
    2. (13 articles) Zygo
    3. (2 articles) Massachusetts General Hospital
    4. (2 articles) Harvard University
    5. (2 articles) Guillermo J. Tearney
    6. (1 articles) University of São Paulo

  5. Popular Articles

  6. Picture Gallery

    Postdoctoral Research Fellowships (Optical Coherence Tomography) at Massachusetts General Hosptial Postdoctoral Research Fellowships (In Vivo Microscopy) At Massachusetts General Hospital Circumpapillary and macular vessel density assessment by optical coherence tomography angiography in eyes with temporal hemianopia from chiasmal compression. Correlation with retinal neural and visual field loss Miniaturizing medical imaging, sensing technology On-chip tunable photonic delay line Canon Xephilio OCT-A1 Optical Coherence Tomography Device Receives FDA 510(k) Clearance Subintimal Versus Intraplaque Recanalization of Coronary Chronic Total Occlusions: Mid-Term Angiographic and OCT Findings From the ISAR-OCT-CTO Registry Review of methods and applications of attenuation coefficient measurements with optical coherence tomography Techniques in Optical Coherence and Resonance for Sensing (Thesis) Recent progress in optical probing and manipulation of tissue: introduction Elimination of Artifacts Caused by the Nonidentity of Parallel Signal-Reception Channels in Spectral Domain Optical Coherence Tomography Changes in Amblyopia Using Optical Coherence Tomography