1. Articles from Woo Jhon Choi

    1-4 of 4
    1. Wideband Electrically Pumped 1050-nm MEMS-Tunable VCSEL for Ophthalmic Imaging

      Wideband Electrically Pumped 1050-nm MEMS-Tunable VCSEL for Ophthalmic Imaging

      In this paper, we present a 1050-nm electrically pumped microelectromechanically tunable vertical cavity surface emitting laser (MEMS-VCSEL) with a record dynamic tuning bandwidth of 63.8 nm, suitable for swept-source optical coherence tomography (SS-OCT) imaging. These devices provide reduced cost and complexity relative to previously demonstrated optically pumped devices by obviating the need for a pump laser and associated hardware. We demonstrate ophthalmic SS-OCT imaging with the electrically-pumped MEMS-VCSEL at a 400 kHz axial scan rate for wide-field imaging of the in vivo human retina over a 12 mm × 12 mm field and for OCT angiography of the macula over ...

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    2. Wideband Electrically-Pumped 1050 nm MEMS-Tunable VCSEL for Ophthalmic Imaging

      Wideband Electrically-Pumped 1050 nm MEMS-Tunable VCSEL for Ophthalmic Imaging

      In this paper, we present a 1050 nm electricallypumped micro-electro-mechanically-tunable vertical-cavitysurface- emitting-laser (MEMS-VCSEL) with a record dynamic tuning bandwidth of 63.8 nm, suitable for swept source optical coherence tomography (SS-OCT) imaging. These devices provide reduced cost & complexity relative to previously demonstrated optically pumped devices by obviating the need for a pump laser and associated hardware. We demonstrate ophthalmic SS-OCT imaging with the electrically-pumped MEMS-VCSEL at a 400 kHz axial scan rate for wide field imaging of the in vivo human retina over a 12 mm × 12 mm field and for OCT angiography of the macula over 6 mm × 6 ...

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    3. Swept source / Fourier domain polarization sensitive optical coherence tomography with a passive polarization delay unit

      Swept source / Fourier domain polarization sensitive optical coherence tomography with a passive polarization delay unit

      Polarization sensitive optical coherence tomography (PS-OCT) is a functional imaging method that provides additional contrast using the light polarizing properties of a sample. This manuscript describes PS-OCT based on ultrahigh speed swept source / Fourier domain OCT operating at 1050nm at 100kHz axial scan rates using single mode fiber optics and a multiplexing approach. Unlike previously reported PS-OCT multiplexing schemes, the method uses a passive polarization delay unit and does not require active polarization modulating devices. This advance decreases system cost and avoids complex synchronization requirements. The polarization delay unit was implemented in the sample beam path in order to simultaneously ...

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    4. Measurement of retinal vascular permeability in a rat model using spectroscopic optical coherence tomography

      Measurement of retinal vascular permeability in a rat model using spectroscopic optical coherence tomography

      Optical coherence tomography (OCT), a diagnostic tool which can perform non-contact, noninvasive, cross-sectional imaging of the retina and anterior eye in real time, has dramatically improved in its resolution and speed in the recent years. In addition to the advancement in hardware, different OCT methods for functional measurements, such as Doppler OCT for quantifying blood flow and generating angiography using OCT phase information, polarization sensitive OCT for measuring intrinsic mechanical / optical tissue property using light of different polarizations, and spectroscopic OCT for measuring blood oxygenation using multiple wavelengths, have been demonstrated and developed. In this thesis, a dual-wavelength spectroscopic OCT ...

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    1-4 of 4
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  2. Topics in the News

    1. (4 articles) Massachusetts Institute of Technology
    2. (3 articles) Thorlabs
    3. (2 articles) Praevium Research
    4. (2 articles) Duke University
    5. (1 articles) Tufts University
    6. (1 articles) Center for Ophthalmic Optics and Lasers
    7. (1 articles) Oregon Health & Science University
    8. (1 articles) Konyang University
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    Measurement of retinal vascular permeability in a rat model using spectroscopic optical coherence tomography Swept source / Fourier domain polarization sensitive optical coherence tomography with a passive polarization delay unit Wideband Electrically-Pumped 1050 nm MEMS-Tunable VCSEL for Ophthalmic Imaging Wideband Electrically Pumped 1050-nm MEMS-Tunable VCSEL for Ophthalmic Imaging Repeatability of Optical Coherence Tomography Angiography Measurements in Patients with Retinal Vein Occlusion Retinal Vascularization Analysis on Optical Coherence Tomography Angiography before and after Intraretinal or Subretinal Fluid Resorption in Exudative Age-Related Macular Degeneration: A Pilot Study Anterior‐segment optical coherence tomography of filtering blebs in the early postoperative period of ab externo SIBS microshunt implantation with mitomycin C: Morphological analysis and correlation with intraocular pressure reduction Combining artificial intelligence and robotics: a novel fully automated optical coherence tomography-based approach for eye disease screening Impact of fundus pigmentation on retinal layer visibility on investigational bedside optical coherence tomography in preterm infants Vascular morphology in facial solar lentigo assessed by optical coherence tomography angiography Macular vascular changes in pregnant women with gestational diabetes mellitus by optical coherence tomography angiography Feasibility of peripheral OCT imaging using a novel integrated SLO ultra-widefield imaging swept-source OCT device