1. Vijay Jayaraman

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    1. Mentioned In 54 Articles

    2. Apparatus and methods for one or more wavelength swept lasers and the detection of signals thereof

      Apparatus and methods for one or more wavelength swept lasers and the detection of signals thereof
      An optical instrument including at least a first and second wavelength swept vertical cavity laser (VCL) sources. The wavelength sweeping ranges spanned by the first and second VCL sources may differ with a region of spectral overlap. The first and second VCL sources may be operable under different modes of operation, wherein the modes of operation differ in at least one of: sweep repetition rate, sweep wavelength range, sweep center ...
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    3. Microscope-Integrated Intraoperative Ultrahigh-Speed Swept-Source Optical Coherence Tomography for Widefield Retinal and Anterior Segment Imaging

      Microscope-Integrated Intraoperative Ultrahigh-Speed Swept-Source Optical Coherence Tomography for Widefield Retinal and Anterior Segment Imaging
      BACKGROUND AND OBJECTIVE: To demonstrate the feasibility of retinal and anterior segment intraoperative widefield imaging using an ultrahigh-speed, swept-source optical coherence tomography (SS-OCT) surgical microscope attachment. PATIENTS AND METHODS: A prototype post-objective SS-OCT using a 1,050-nm wavelength, 400 kHz A-scan rate, vertical cavity surface-emitting laser (VCSEL) light source was integrated to a commercial ophthalmic surgical microscope after the objective. Each widefield OCT data set was acquired in 3 seconds ...
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    4. Cycloid scanning for wide field optical coherence tomography endomicroscopy and angiography in vivo

      Cycloid scanning for wide field optical coherence tomography endomicroscopy and angiography in vivo
      Devices that perform wide field-of-view (FOV) precision optical scanning are important for endoscopic assessment and diagnosis of luminal organ disease such as in gastroenterology. Optical scanning for in vivo endoscopic imaging has traditionally relied on one or more proximal mechanical actuators, limiting scan accuracy and imaging speed. There is a need for rapid and precise two-dimensional (2D) microscanning technologies to enable the translation of benchtop scanning microscopies to in vivo ...
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    5. Widely tunable short cavity laser

      Widely tunable short cavity laser
      A tunable source includes a short-cavity laser optimized for performance and reliability in SSOCT imaging systems, spectroscopic detection systems, and other types of detection and sensing systems. The short cavity laser has a large free spectral range cavity, fast tuning response and single transverse, longitudinal and polarization mode operation, and includes embodiments for fast and wide tuning, and optimized spectral shaping. Disclosed are both electrical and optical pumping in a ...
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    6. Ultrahigh-speed endoscopic optical coherence tomography and angiography enables delineation of lateral margins of endoscopic mucosal resection: a case report

      Ultrahigh-speed endoscopic optical coherence tomography and angiography enables delineation of lateral margins of endoscopic mucosal resection: a case report
      Endoscopic mucosal resection (EMR) is a common technique for resecting dysplastic lesions in Barretts esophagus (BE), stomach, and colon, 1 but precise delineation of dysplastic margins before resection and verification of complete removal after resection remain challenging. 2 , 3 Endoscopic optical coherence tomography (OCT) enables three-dimensional visualization of tissue microstructure and is commercially available as Volumetric Laser Endomicroscopy (NinePoint Medical, Bedford, MA, USA). 4 , 5 We recently developed an ultrahigh-speed ...
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    7. Widely tunable swept source

      Widely tunable swept source
      A high-speed, single-mode, high power, reliable and manufacturable wavelength-tunable light source operative to emit wavelength tunable radiation over a wavelength range contained in a wavelength span between about 950 nm and about 1150 nm, including a vertical cavity laser (VCL), the VCL having a gain region with at least one compressively strained quantum well containing Indium, Gallium, and Arsenic.
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    8. Endoscopic forward-viewing optical coherence tomography and angiography with MHz swept source

      Endoscopic forward-viewing optical coherence tomography and angiography with MHz swept source
      Endoscopic optical coherence tomography (OCT) instruments are mostly side viewing and rely on at least one proximal scan, thus limiting accuracy of volumetric imaging and en face visualization. Previous forward-viewing OCT devices had limited axial scan speeds. We report a forward-viewing fiber scanning 3D-OCT probe with 900 m field of view and 5 m transverse resolution, imaging at 1 MHz axial scan rate in the human gastrointestinal tract. The probe ...
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    9. Tunable laser array system

      Tunable laser array system
      A system for swept source optical coherence tomography, the system including a light source emitting multiplexed wavelength-swept radiation over a total wavelength range, the light source including N wavelength-swept vertical cavity lasers (VCL) emitting N tunable VCL outputs having N wavelength trajectories, a combiner for combining the N tunable VCL optical outputs into a common optical path to create the multiplexed wavelength-swept radiation, a splitter for splitting the multiplexed wavelength-swept ...
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    10. Cubic meter volume optical coherence tomography

      Cubic meter volume optical coherence tomography
      Optical coherence tomography (OCT) is a powerful three-dimensional (3D) imaging modality with micrometer-scale axial resolution and up to multi-GigaVoxel/s imaging speed. However, the imaging range of high-speed OCT has been limited. Here, we report 3D OCT over cubic meter volumes using a long coherence length, 1310 nm vertical-cavity surface-emitting laser and silicon photonic integrated circuit dual-quadrature receiver technology combined with enhanced signal processing. We achieved 15 m depth resolution ...
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    11. Volumetric Mapping of Barrett’s Esophagus and Dysplasia With en face Optical Coherence Tomography Tethered Capsule

      Volumetric Mapping of Barrett’s Esophagus and Dysplasia With en face Optical Coherence Tomography Tethered Capsule
      To the Editor: Dysplasia in Barretts Esophagus (BE) is patchy ( 1 ) and sometimes missed by random biopsies. Optical coherence tomography (OCT) can image large areas of the esophagus; however, slow imaging speeds in earlier studies limited visualization to cross-sections. Cross-sectional OCT detected high-grade dysplasia with sensitivity / specificity of ~80 % ( 2 , 3 ). Tethered OCT capsules were demonstrated for cross-sectional imaging in unsedated screening to detect BE ( 4 , 5 ). Our group recently ...
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    12. ULTRAHIGH SPEED SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF RETINAL AND CHORIOCAPILLARIS ALTERATIONS IN DIABETIC PATIENTS WITH AND WITHOUT RETINOPATHY

      ULTRAHIGH SPEED SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF RETINAL AND CHORIOCAPILLARIS ALTERATIONS IN DIABETIC PATIENTS WITH AND WITHOUT RETINOPATHY
      Purpose: To investigate the utility of ultrahigh speed, swept source optical coherence tomography angiography in visualizing retinal microvascular and choriocapillaris (CC) changes in diabetic patients. Methods: The study was prospective and cross-sectional. A 1,050 nm wavelength, 400 kHz A-scan rate swept source optical coherence tomography prototype was used to perform volumetric optical coherence tomography angiography of the retinal and CC vasculatures in diabetic patients and normal subjects. Sixty-three eyes ...
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    13. Choroidal Neovascularization Analyzed on Ultrahigh-Speed Swept-Source Optical Coherence Tomography Angiography Compared to Spectral-Domain Optical Coherence Tomography Angiography

      Choroidal Neovascularization Analyzed on Ultrahigh-Speed Swept-Source Optical Coherence Tomography Angiography Compared to Spectral-Domain Optical Coherence Tomography Angiography
      Purpose To compare visualization of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) using an ultrahigh-speed swept-source (SS) optical coherence tomography angiography (OCTA) prototype vs a spectral-domain (SD) OCTA device. Design Comparative analysis of diagnostic instruments. Methods Patients were prospectively recruited to be imaged on SD OCT and SS OCT devices on the same day. The SD OCT device employed is the RTVue Avanti (Optovue, Inc, Fremont, California, USA ...
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    14. Amplified widely tunable short cavity laser

      Amplified widely tunable short cavity laser
      An amplified tunable source includes a short-cavity laser coupled to an optical amplifier for high power, spectrally shaped operation. The short-cavity laser is coupled to a quantum well semiconductor optical amplifier with two quantum states for broadened gain. Two preferred wavelength ranges of the amplified tunable source include 1200-1400 nm and 800-1100 nm. Also disclosed is the short cavity tunable laser coupled to a fiber amplifier. Various combinations of tunable ...
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    15. Tunable short cavity laser sensor

      Tunable short cavity laser sensor
      Optical systems employ a tunable source which includes a short cavity laser with a large free spectral range cavity, fast tuning response, and single transverse and longitudinal mode operation. Systems for optical spectroscopy with optimized scanning, a system for optical beam steering and a system for a tunable local oscillator are disclosed.
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    16. Polarization stable widely tunable short cavity laser

      Polarization stable widely tunable short cavity laser
      A tunable source includes a short-cavity laser optimized for performance and reliability in SSOCT imaging systems, spectroscopic detection systems, and other types of detection and sensing systems. A short cavity laser with a large free spectral range cavity, fast tuning response and single transverse, longitudinal and polarization mode operation is disclosed. Methods for obtaining polarization stable operation of the tunable source are presented.
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    17. 1-15 of 54 1 2 3 4 »
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    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
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      Jobs & Studentships, Student Theses, Textbooks
  2. About Vijay Jayaraman

    Vijay Jayaraman

    Vijaysekhar Jayaraman is the founder of Praevium Research, and principal investigator on a number of Praevium’s SBIR efforts. He received his BS/MS in Electrical Engineering from the Massachusetts Institute of Technology in 1985, and a Ph.D. in Electrical Engineering from University of California, Santa Barbara in 1994. From 1985-1988, Dr. Jayaraman was a staff member at MIT Lincoln Laboratory, where he contributed to the development of a space-based optical heterodyne communication system. Prior to founding Praevium Research in 2001, Dr. Jayaraman’s notable accomplishments included the first demonstration of the SGDBR tunable laser while a graduate student at UCSB. This device has since been commercialized by a large telecommunications company. Dr. Jayaraman also contributed to the early  development development of electrically and optically pumped 1300 nm VCSELs while employed at Optical Concepts/W.L Gore and associates and UCSB.

  3. Quotes

    1. MEMS-VCSELs have previously demonstrated speed and coherence length advantages for SS-OCT, but questions remained as to whether MEMS-VCSEL tuning range could compete with widely tunable externalcavity lasers...We believe that this work demonstrates for the first time that MEMS-VCSEL tuning range can be on a par with these other devices...We hope to see a renaissance in the MEMS-VCSEL field...We anticipate new wavelength regimes and wider tuning ranges will be reported in the next few years, as well as new spectroscopic applications. We also anticipate significant cost reductions as we take advantage of Thorlabs’ volume semiconductor manufacturing. We look forward to seeing MEMS-VCSELs become an established commercial product for both medical and spectroscopic applications over the next decade.
      In A Clean Sweep for MEMS-VCSELs
    2. Though MEMs VCSELs first emerged for telecom, we believe OCT could become their highest impact application.
      In Praevium Research, Thorlabs, & MIT Demonstrate High Performance Swept Source Laser for OCT and Other Applications