1. Massachusetts Institute of Technology

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    1. Mentioned In 549 Articles

    2. Imaging needle for optical coherence tomography

      Imaging needle for optical coherence tomography
      We describe a miniature optical coherence tomography (OCT) imaging needle that can be inserted into solid tissues and organs to permit interstitial imaging of their internal microstructures with micrometer scale resolution and minimal trauma. A novel rotational coupler with a glass capillary tube is also presented that couples light from a rotating single-mode fiber to a stationary one. A prototype needle with a 27-gauge 410-mm outer diameter has been developed ...
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    3. Grating based phase control optical delay line

      An apparatus for performing high speed scanning of an optical delay and its application for performing optical interferometry, ranging, and imaging, including cross sectional imaging using optical coherence tomography, is disclosed. The apparatus achieves optical delay scanning by using diffractive optical elements in conjunction with imaging optics. In one embodiment a diffraction grating disperses an optical beam into different spectral frequency or wavelength components which are collimated by a lens ...
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    4. Three-dimensional light absorption spectroscopic imaging

      An absorption imaging spectrometer for providing a three-dimensional spectral image of a light-transmitting sample. Temporally incoherent light is used to illuminate the sample, with a portion of the beam split off as a reference beam and subsequently recombined with the return beam from the sample after a variable delay path. An optical configuration is provided for modulating a time delay of the reference beam, with the interferogram obtained at each ...
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    5. Method and apparatus for performing optical measurements using a rapidly frequency-tuned laser

      Method and apparatus for performing optical measurements using a rapidly frequency-tuned laser
      An optical system, in one embodiment including an external-cavity frequency-tuned laser having a tunable longitudinal cavity mode and a center tunable wavelength. The external-cavity frequency-tuned laser includes an optical cavity, an optical gain medium positioned within the optical cavity, and a rapid tuning wavelength selecting device positioned to receive light from the optical gain medium and adapted to return selected wavelengths of light to the optical gain medium. The external-cavity ...
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    6. Apparatus and method for accessing data on multilayered optical media

      Apparatus and method for accessing data on multilayered optical media
      Apparatus and methods for accessing data on a multilayered optical storage medium. The apparatus uses the time-of-flight of illumination directed to and reflected by the layers of the optical medium to access data stored on a desired layer of the medium. More particularly, alterations in illumination reflected from the desired layer are detected to access data stored on the layer. In accordance with embodiments of the invention utilizing interferometric techniques ...
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    7. Optical information storage via amplitude modulation

      A system for three-dimensionally storing and encoding information in an optical storage medium. Information at a surface location is encoded according to the surface depth or width of the location. The information is then retrieved through the use of intensity measurements of light modulated by the depth or width of the storage location. The intensity of the light represents the data value stored at the location.
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    8. Apparatus and methods for reading multilayer storage media using short coherence length sources

      Apparatus and methods for reading multilayer storage media using short coherence length sources
      Apparatus and methods for reading multilayer optical data storage media are described. The apparatus includes a short coherence length light source and an optical system. The optical system focuses the light from the source onto the layers of the storage media. The coherence length of the source is less than 100 microns or less than the spacing between the layers. The Rayleigh range within the storage media may also be ...
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    9. High-speed phase- and group-delay scanning with a grating-based phase control delay line.

      Related Articles High-speed phase- and group-delay scanning with a grating-based phase control delay line. Opt Lett. 1997 Dec 1;22(23):1811-3 Authors: Tearney GJ, Bouma BE, Fujimoto JG A rapid-scanning optical delay line that employs phase control has several advantages, including high speed, high duty cycle, phase- and group-delay independence, and group-velocity dispersion compensation, over existing optical delay methods for interferometric optical ranging applications. We discuss the grating-based phase-control ...
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    10. Forward-imaging instruments for optical coherence tomography

      Forward-imaging instruments for optical coherence tomography
      We discuss the design and implementation of forward-imaging instruments for optical coherence tomography (OCT), which require the delivery, scanning, and collection of single-spatial-mode optical radiation. A hand-held surgical probe for use in open surgery can provide cross-sectional images of subsurface tissue before surgical incisions are made. A rigid laparoscope for minimally invasive surgical OCT imaging provides a simultaneous enface view of the area being imaged. OCT imaging is demonstrated on ...
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    11. Optical coherence tomography using a frequency-tunable optical source

      Optical coherence tomography using a frequency-tunable optical source
      We have developed a simple, wide-optical-bandwidth, high-resolution system for performing rapid optical frequency domain reflectometry measurements and applied it to multidimensional tomographic imaging. The source is a grating-tuned external cavity semiconductor laser with a tuning capability of 25 nm in 100 ms. We discuss system performance and show a two-dimensional optical coherence tomography image of a thin glass sandwich structure as a preliminary demonstration of the systems depth and resolution ...
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    12. Application of optical coherence tomography in nondestructive evaluation of material microstructure

      Application of optical coherence tomography in nondestructive evaluation of material microstructure
      Techniques for nondestructive evaluation (NDE), testing, and inspection of parts during manufacturing and materials processing, in situ, or during design, is a key technology. The authors use optical coherence tomography (OCT) is a high-resolution, high-sensitivity imaging technology that is based on the coherence properties of light.
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    13. 526-540 of 549 « 1 2 ... 33 34 35 36 37 »
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  2. About Massachusetts Institute of Technology

    Massachusetts Institute of Technology

    Massachusetts Institute of Technology (MIT) is a private, coeducational research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing 32 academic departments, with a strong emphasis in theoretical, applied, and interdisciplinary scientific and technological research.  Laser Medicine and Medical Imaging Group at MIT.  The RLE Laser Medicine and Medical Imaging Group and its close collaborators were the originators of optical coherence tomography (OCT), a diagnostic technology now used in a growing number of medical fields. The group currently works to further understand and exploit the capabilities of OCT technology, with ongoing investigations in topics related to optical coherence microscopy development and optical biopsy using OCT.