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    1. Business Forum: Professional society in our photonics ecosystem

      Business Forum: Professional society in our photonics ecosystem

      This is the second in a series of interviews of CEOs of our professional societies to give us a better understanding of the ecosystem of our industry. It is a pleasure for me to chat with Eugene Arthurs, someone I have known for more than 30 years. Arthurs is CEO of the International Society for Optics and Photonics after joining SPIE as executive director in 1999. Prior to this, he was president and CEO of Cleveland Crystals (CCI); before that, he was with Quantronix and Oriel. Arthurs received his B.Sc. with honors in Physics and his Ph.D. in ...

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    2. Laser plus phosphor emits white light without

      Laser plus phosphor emits white light without

      Combining a blue-emitting indium gallium nitride (InGaN) LED with a yellow YAG phosphor has produced one of most successful commercial photonic devices ever—the white-light LED. But there is a problem: InGaN LEDs suffer from efficiency droop, in which their efficiency at high currents, and therefore high optical outputs, is lower than that for low currents and optical outputs. However, other InGaN light sources—blue- and near-UV-emitting laser diodes—do not suffer from this problem. With this in mind, researchers at the University of California, Santa Barbara (UCSB), led by material scientists Kristin Denault and Michael Cantore, have combined laser ...

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    3. Akinetic all-semiconductor swept lasers boost OCT image quality

      Akinetic all-semiconductor swept lasers boost OCT image quality

      Optical coherence tomography (OCT) image quality continues to improve thanks to advances in detection systems and improved light sources such as wavelength-tunable vertical-cavity surface-emitting lasers (VCSELs) . But a different light source that eliminates the mechanical tuning of VCSEL and external-cavity lasers is rapidly gaining momentum, as it could offer superior OCT image quality and potentially lower-cost manufacture: akinetic all-semiconductor swept laser sources from Insight (Lafayette, CO). 1 Nearly all swept-wavelength light sources use mechanical means to move optical filter elements or microelectromechanical systems (MEMS) mirrors to tune the output wavelength; unfortunately, these mechanical elements can exhibit hysteresis, cause cavity instabilities ...

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    4. OPTICAL COHERENCE TOMOGRAPHY: Dual-window technique enhances true-color spectroscopic OCT

      OPTICAL COHERENCE TOMOGRAPHY: Dual-window technique enhances true-color spectroscopic OCT

      Spectroscopic optical coherence tomography (SOCT) and variations such as Raman spectroscopic OCT (RS-OCT) often use absorption contrast agents such as gold nanoparticles to enhance diagnostics; however, these particles require modification to be compatible with infrared (IR) illumination. The light sources can also limit analysis of many biological components that absorb in the visible region. An alternative technique from Duke University (Durham, NC) researchers called molecular imaging true-color spectroscopic (METRiCS) OCT uses a broadband laser source (centered in the visible spectrum) and a dual-window (DW) data-processing method that improves imaging when using various IR and visible absorption contrast agents, simultaneously improving ...

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      Mentions: Duke University
    5. Random laser produces speckle-free images

      Random laser produces speckle-free images

      Random lasers may have a future in imaging. A team at Yale University (New Haven, CT) who last year made random lasers with low spatial coherence has now used those low-coherence lasers for speckle-free imaging. The demonstration could open the door to new laser applications in biological imaging, picoprojectors, and cinema projectors. A byproduct of coherence, laser speckle is a shifting pattern of bright and dark zones produced when a laser beam passes through a scattering medium. It’s tolerable in many laser applications, but speckle degrades images recorded in laser light or displayed by laser projectors. “Speckle is a ...

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    6. Non-Medical Applications of OCT - A WebEx by Dr. Michael Leitner June 25, 2012

      Non-Medical Applications of OCT - A WebEx by Dr. Michael Leitner  June 25, 2012

      Optical coherence tomography (OCT) is a non-invasive imaging technique allowing fast and high-quality two- and three dimensional imaging of semi-transparent and turbid media. So far, biomedical research and diagnostics have been the main driving forces for the reported applications and progress in OCT. However, the characteristics of OCT, specifically the ability to provide high-resolution images and depth-resolved information also in strongly scattering media in a contact-free and non destructive way, render this technique also attractive for a broad spectrum of research topics and applications outside the biomedical field. In this webcast, Dr. Michael Leitner, head of the optical coherence tomography ...

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    7. Hybrid photodiodes promise cost-effective short-wave IR imaging

      Hybrid photodiodes promise cost-effective short-wave IR imaging
      A combination of organic and inorganic nanoscale materials, along with solution processing, enables a tunable imager for short-wave infrared imaging. The growing interest in short-wavelength infrared (SWIR) imagers is related to the increasing number of applications in this particular spectral region. Wavelengths between the silicon bandgap limit of about 1.1 and 2 µm are of commercial interest because of the low water absorption in this spectral region. Photodiodes for the SWIR are usually made
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    8. Holographic live-tissue imaging uses photorefractive polymer

      Holographic live-tissue imaging uses photorefractive polymer
      Collection of three-dimensional (3-D) data from confocal scanning microscopy and optical coherence tomography (OCT) is lengthy due to the sequential acquisition of image pixels required for these methods; for this reason, researchers at the University of Cologne (Cologne, Germany) and Purdue University (West Lafayette, IN) are pursuing a variation of holographic optical coherence imaging (HOCI) as a faster depth-resolved imaging technique.1 Because the whole image is formed in one step, lengthy point scanning is avoided. However, another major obstacle for any tissue-imaging system is light scattering and its impact on image resolution. To combat this concern, the research team ...
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    9. Molecular imaging gets a new tool

      Molecular imaging gets a new tool
      In September of last year I happened to be in Europe on “beam day”—the day on which the Large Hadron Collider (LHC) was turned on for the first time. The LHC is a particle accelerator at CERN, the European high-energy physics laboratory near Geneva in Switzerland. There can be few events—and even fewer scientific ones—that have achieved such universal pan-European media coverage as did this firing up of the LHC. It was, I would guess, front-page news in all of Europe’s leading newspapers. And ev
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    10. OCT aims for industrial application

      OCT aims for industrial application
      The speed, precision, and cost benefits of optical coherence tomography are beginning to attract the interest of industrial end users. For detailed subsurface imaging of small, semiopaque 2-D surface areas or 3-D structures, OCT is just the thing. When optical coherence tomography (OCT) was introduced in the early 1990s, it was immediately recognized for its ability to produce high-resolution, depth-resolved imagery of biological tissue. Its impact on ophthalmology is evident in a recent article published by Ocular Surgery News. Writes author Richard Lindstrom, “Every day in clinical practice around the world, optical coherence tomography is making a significant contribution to ...
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    11. Munich sends optimistic message

      Munich sends optimistic message
      The World of Photonics Congress attracted approximately 3100 delegates and encompassed seven different conferences, of which two covered bio: European Conferences on Biomedical Optics and Medical Laser Applications.... Among the bio conferences, photoacoustics, optical coherence tomography (OCT), and microscopy were key topics.
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    12. Full-field OCT approaches clinical application

      Full-field OCT approaches clinical application
      Newly developed Cell OCT, an approach to full-field optical coherence tomography, has enabled researchers to image breast-cancer tissue with histology-like results. Full-field OCT is an en face (transverse), broadband interferometric approach to optical coherence tomography (OCT) that’s been in use for life-science research for more than a decade.1–3 The technique offers many advantages, including fast tissue imaging at the cellular level, which is why at ESPCI (Ecole Superieure Physique Chimie Industrielles; Paris, France) we call it “Cell OCT.” Recently, full-field Cell OCT proved able to virtually slice ablated breast tumors and lymph nodes with 1 µm isotropic ...
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    13. Polarimetry improves spectral measurement of swept-wavelength sources

      Polarimetry improves spectral measurement of swept-wavelength sources
      Although optical-spectrum analysis and polarization measurement methods are not generally related, a collaborative effort by scientists at Tianjin University (Tianjin, China), General Photonics (Chino, CA), and the University of Southern California (Los Angeles, CA) has resulted in a polarimeter-based optical-spectrum analyzer (P-OSA) that measures with a speed and resolution that cannot be achieved using traditional grating-based, filter-based, or interferometric methods.1 In fact, the method w
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    14. Medical imaging company acquires Axsun Technologies for its OCT expertise

      December 30, 2008--Volcano Corporation (San Diego, CA), developer of products for the diagnosis and treatment of coronary and peripheral artery disease, entered into a definitive agreement to acquire Axsun Technologies (Billerica, MA), a privately held company that develops lasers and optical engines used in optical coherence tomography (OCT) imaging systems and photonic components and subsystems used in other industrial applications.
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    15. OCT technique measures bulk refractive index

      OCT technique measures bulk refractive index
      Although critical-angle refractometry techniques are well-established for measuring the refractive index of homogeneous transparent materials with an uncertainty on the order of 10-6, these techniques only measure the index at a smooth, planar surface of the material–a problem for soft biological materials, considering that any surface treatments can easily modify refractive index. Building on the application of rotationally and angularly resolved low-coherence interferometry (LCI) and standard optical coherence tomography (OCT) techniques for imaging and birefringence measurements, researchers in the Biophotonics Group at the National Physical Laboratory (NPL; Teddington, England) are using Michelson LCI and a commercial OCT system to ...
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    16. Nonclassical OCT images biological sample

      Nonclassical OCT images biological sample
      Quantum optical coherence tomography (OCT) has, for the first time, been shown to be a viable biological imaging technique, says M. Boshra Nasr, a postdoctoral researcher in the Quantum Imaging Laboratory at Boston University (Boston, MA). Nasr led a project that has produced the first experimental quantum OCT (QOCT) images of a biological sample. Quantum OCT holds strong appeal because, unlike classical OCT, it is inherently immune to group-velocity dispersion (GVD), which degrades axial resolution.1 This immunity is a direct result of the frequency entanglement inherent in the light source used in such a scheme; QOCT is a fourth-order ...
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    17. Biomedical Imaging: MEMS scanners enable in vivo 3-D OCT

      Biomedical Imaging: MEMS scanners enable in vivo 3-D OCT
      While nonoptical medical imaging techniques such as computed tomography, magnetic-resonance imaging, and ultrasound can be very useful in guiding surgical procedures, they lack the spatial resolution required for revealing tissue microarchitecture, which can be important in time-critical applications, such as staging of tumors.1 In contrast, optical imaging modalities such as confocal, two-photon, and fluorescence microscopy, and optical coherence tomography (OCT) provide depth-resolved imaging even in turbid media, with cellular-level detail. In particular, OCT offers imaging depths of several millimeters through human tissue with micrometer resolution in all three dimensions and can extract additional properties of the sample (such as ...
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    1-24 of 34 1 2 »
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