Tunable Sources -Optical Coherence Tomography News

Articles in category: Tunable Sources

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1. OCT-angiography: A qualitative and quantitative comparison of 4 OCT-A devices
  
  Explore Journals | PLOS May 10 2017 Tunable Sources
  
  Article Authors Metrics Comments Related Content Abstract Introduction Methods Results Discussion Supporting information Acknowledgments Author Contributions References Reader Comments (0) Media Coverage Figures Abstract Purpose To compare the quality of four OCT-angiography(OCT-A) modules. Method The retina of nineteen healthy volunteers were scanned with four OCT-devices (Topcon DRI-OCT Triton Swept-source OCT, Optovue RTVue-XR, a prototype Spectralis OCT2, Heidelberg-Engineering and Zeiss Cirrus 5000-HD-OCT). The device-software generated en-face OCT-A images of the superficial (SCP) and deep capillary plexuses (DCP) were evaluated and scored by 3 independent retinal imaging experts. The SCP vessel density was assessed using Angiotool-software. After the inter-grader reliability assessment ...
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  Mentions: Optovue Heidelberg Engineering Nidek
2. Extended bandwidth wavelength swept laser source for high resolution optical frequency domain imaging
  
  Explore OSA | OSA Publishing Apr 4 2017 Tunable Sources
  
  Improving the axial resolution by providing wider bandwidth wavelength swept lasers remains an important issue for optical frequency domain imaging (OFDI). Here, we demonstrate a wide tuning range, all-fiber wavelength swept laser at a center wavelength of 1250 nm by combining two ring cavities that share a single Fabry-Perot tunable filter. The two cavities contain semiconductor optical amplifiers with central wavelengths of 1190 nm and 1292 nm, respectively. To avoid disturbing interference effects in the overlapping spectral region, we modulated the amplifiers in order to obtain consecutive wavelength sweeps in the two spectral regions. The two sweeps were fused together ...
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  Mentions: Brett E. Bouma Massachusetts General Hospital Harvard University
3. Phase-noise analysis of swept-source optical coherence tomography systems
  
  Explore OSA | OSA Publishing Mar 23 2017 Tunable Sources
  
  We propose a new model to characterize the phase noise in swept-source optical coherence tomography (SS-OCT). The new model explicitly incorporates scanning variability, timing jitter, and sample location in addition to intensity noise (shot noise). The model was analyzed and validated by using both Monte Carlo methods and experiments. We suggest that the proposed model can be used as a guideline for future SS-OCT experimental designs.
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  Mentions: Columbia University Christine Hendon
4. Analysis of polygonal scanning heads: from industrial to high-end applications in swept sources for OCT
  
  Explore Conference Proceedings Mar 18 2017 Tunable Sources
  
  An analysis of polygonal mirror (PM) scanning heads has been performed, in order to provide a tool for their optimal design. The theory developed brings under the same umbrella applications that range from industrial dimensional measurements to high-end biomedical imaging, for example for broadband laser sources swept in frequency for Swept Source Optical Coherence Tomography (SS-OCT). The different characteristic parameters of the PM scanning heads were considered in order to achieve a rigorous analysis: number of PM facets, inner radius of the PM, eccentricity of the PM pivot with regard to the incident fixed laser beam, distance from this beam ...
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  Mentions: Virgil-Florin Duma
5. Wavelength tunable laser device and optical coherence tomography apparatus
  
  Explore uspto.gov Mar 14 2017 Patents , Tunable Sources
  
  A wavelength tunable laser device, including: a first reflector; a second reflector; an active layer formed between the first reflector and the second reflector; a quantum well structure layer that exhibits a quantum confined stark effect; and an electrode configured to apply a reverse bias voltage to the quantum well structure layer, wherein the active layer and the second reflector have a gap formed therebetween, the gap having a length to be changed to thereby sweep a resonance wavelength, and wherein the electrode is further configured to change application of the reverse bias voltage to be applied to the quantum ...
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  Mentions: Canon Medical Systems
6. A linearly frequency-swept high-speed-rate multi-wavelength laser for optical coherence tomography
  
  Explore Conference Proceedings Mar 1 2017 Tunable Sources
  
  We proposed and demonstrated a linearly frequency-swept multi-wavelength laser source for optical coherence tomography (OCT) eliminating the need of wavenumber space resampling in the postprocessing progress. The source consists of a multi-wavelength fiber laser source (MFS) and an optical sweeping loop. In this novel laser source, an equally spaced multi-wavelength laser is swept simultaneously by a certain step each time in the frequency domain in the optical sweeping loop. The sweeping step is determined by radio frequency (RF) signal which can be precisely controlled. Thus the sweeping behavior strictly maintains a linear relationship between time and frequency. We experimentally achieved ...
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  Mentions: Tianjin University
7. Stable wavelength-swept light source designed for industrial applications using KTN beam-scanning technology
  
  Explore Conference Proceedings Mar 1 2017 Tunable Sources
  
  Using light-beam scanning technology based on a potassium tantalate niobate (KTa 1-x Nb x O 3 , KTN) single crystal, we constructed a wavelength-swept light source for industrial applications. The KTN crystal is placed in an external cavity as an electro-optic deflector for wavelength scanning without any mechanical operation. Cavity arrangement and mechanism elements are specially designed for long-term stability and environmental robustness. In addition, we updated the handling of the KTN crystal. We used a pair of thermistors for accurate temperature monitoring, and weakly irradiated the crystal with a 405-nm light during operation to achieve drift suppression. We selected a ...
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  Mentions: Hamamatsu Photonics NTT
8. Analysis of FDML lasers with meter range coherence
  
  Explore Conference Proceedings Mar 1 2017 Tunable Sources
  
  FDML lasers provide sweep rates in the MHz range at wide optical bandwidths, making them ideal sources for high speed OCT. Recently, at lower speed, ultralong-range swept-source OCT has been demonstrated using a tunable vertical cavity surface emitting laser (VCSEL) and also using a Vernier-tunable laser. These sources provide relatively high sweep rates and meter range coherence lengths. In order to achieve similar coherence, we developed an extremely well dispersion compensated Fourier Domain Mode Locked (FDML) laser, running at 3.2 MHz sweep rate and 120 nm spectral bandwidth. We demonstrate that this laser offers meter range coherence and enables ...
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  Mentions: Robert A. Huber Wolfgang Wieser University of Lübeck
9. High frame-rate en face optical coherence tomography system using KTN optical beam deflector
  
  Explore Conference Proceedings Feb 23 2017 Tunable Sources
  
  We developed high frame-rate en face optical coherence tomography (OCT) system using KTa 1-x Nb x O 3 (KTN) optical beam deflector. In the imaging system, the fast scanning was performed at 200 kHz by the KTN optical beam deflector, while the slow scanning was performed at 800 Hz by the galvanometer mirror. As a preliminary experiment, we succeeded in obtaining en face OCT images of human fingerprint with a frame rate of 800 fps. This is the highest frame-rate obtained using time-domain (TD) en face OCT imaging. The 3D-OCT image of sweat gland was also obtained by our imaging ...
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  Mentions: NTT Osaka University
10. Dependence on fiber Fabry-Pérot tunable filter characteristics in an all-fiber swept-wavelength laser for use in an optical coherence tomography system
  
  Explore Conference Proceedings Feb 23 2017 Tunable Sources
  
  Optical coherence tomography (OCT) has become a useful and common diagnostic tool within the field of ophthalmology. Although presently a commercial technology, research continues in improving image quality and applying the imaging method to other tissue types. Swept-wavelength lasers based upon fiber ring cavities containing fiber Fabry-P´erot tunable filters (FFP-TF), as an intracavity element, provide swept-source optical coherence tomography (SS-OCT) systems with a robust and scalable platform. The FFP-TF can be fabricated within a large range of operating wavelengths, free spectral ranges (FSR), and finesses. To date, FFP-TFs have been fabricated at operating wavelengths from 400 nm to 2 ...
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  Mentions: Micron Optics
11. Frequency shifting optical swept lightsource system and apparatus to which the system is applied
  
  Explore uspto.gov Feb 21 2017 Tunable Sources
  
  Provided is a frequency shifting optical swept light source system. The system includes a light source that emits light; an amplifier that amplifies the light output from the light source; an optical converter that shifts a frequency of the amplified light and compresses a spectrum of the amplified light; and a controller that controls a current signal applied to the light source such that a repetition rate of the light output from the light source is adjusted, so that an intensity of the amplified light is adjusted, to thereby adjust a position of the compressed spectrum with respect to a ...
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  Mentions: Yoonchan Jeong Samsung
12. Integrated dual swept source alternating same scan band for OCT medical imaging
  
  Explore uspto.gov Feb 21 2017 Patents , Tunable Sources
  
  An optical coherence analysis system comprising: a first swept source that generates a first optical signal that is tuned over a first spectral scan band, a second swept source that generates a second optical signal that is tuned over a second spectral scan band, a combiner for combining the first optical signal and the second optical signal to form a combined optical signal, an interferometer for dividing the combined optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample, and a detector system for detecting an interference signal generated from the ...
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  Mentions: Axsun Technologies Dale Flanders Bart Johnson
13. VCSEL-based swept source for low-cost optical coherence tomography
  
  Explore OSA | OSA Publishing Jan 26 2017 Tunable Sources
  
  We present a novel wavelength-swept laser source for optical coherence tomography (OCT) which is based on the conventional laser diode technology of the verticalcavity surface-emitting laser (VCSEL). In our self-heating sweep VCSEL (SS-VCSEL), a VCSEL device is simply driven by ramped pulses of currents in direct intensity modulation. The intrinsic property of VCSEL produces a frequency-swept output through the self-heating effect. By the injected current, the temperature of the active region is gradually increased in this effect. Consequently, it changes the wavelength of the laser output by itself. In this study, various characteristics of our SS-VCSEL were experimentally investigated for ...
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14. Coherence properties of short cavity swept lasers
  
  Explore OSA | OSA Publishing Jan 24 2017 Tunable Sources
  
  It has been shown theoretically and experimentally that short cavity swept lasers are passively mode locked. We develop a mathematical model of these lasers and the light field solutions are used to predict the coherence length and coherence revival behavior. The calculations compare favorably with data from a 990–1100 nm laser swept at 100 kHz suitable for optical coherence tomography applications.
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  Mentions: Axsun Technologies Dale Flanders Brian D. Goldberg
15. Wavelength tunable light source
  
  Explore uspto.gov Dec 6 2016 Funding , Tunable Sources
  
  To provide a wavelength tunable light source which can both ensure operation speed and reduce a drive voltage. A wavelength tunable light source according to the present invention includes a pair of reflectors at least one of which is a movable reflector, an active layer provided between the pair of reflectors, and a beam on part of which the movable reflector is formed and which is supported by a support member. The beam includes a blade part projecting between the support member and the movable reflector in a direction intersecting a stretching direction of the beam, and a center of ...
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  Mentions: Canon Medical Systems
16. Full-Field Optical Coherence Tomography Using Galvo Filter-Based Wavelength Swept Laser
  
  Explore MDPI Open Access Journals Platform Nov 17 2016 Tunable Sources
  
  We report a wavelength swept laser-based full-field optical coherence tomography for measuring the surfaces and thicknesses of refractive and reflective samples. The system consists of a galvo filter–based wavelength swept laser and a simple Michelson interferometer. Combinations of the reflective and refractive samples are used to demonstrate the performance of the system. By synchronizing the camera with the source, the cross-sectional information of the samples can be seen after each sweep of the swept source. This system can be effective for the thickness measurement of optical thin films as well as for the depth investigation of samples in industrial ...
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  Mentions: Jeehyun Kim Kyungpook National University
17. Optimized device for swept source optical coherence domain reflectometry and tomography
  
  Explore uspto.gov Nov 15 2016 Ophthalmology , Patents , Tunable Sources
  
  Optimized device for swept source optical coherence domain reflectometry and tomography. In the coherence-optical device, light, with the aid of an interferometer, is used for distance-measuring and imaging purposes on reflecting and scattering areas of the human eye. The optimized device according to the invention consists of includes a tunable light source, matched to the sought-after measurement region ZOCT, with a resonator length LR, an interferometric measurement arrangement, a data capturing unit for capturing the light portions scattered back from the sample and a data processing unit. Here the resonator length LR of the tunable light source is matched not ...
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  Mentions: Carl Zeiss Meditec
18. Wavelength-swept fiber laser based on acousto-optic tuning method
  
  Explore Conference Proceedings Nov 6 2016 Tunable Sources
  
  In this study, we have demonstrated a wavelength-swept fiber laser based on an acousto-optic tunable filter(AOTF) as a selective element and a semiconductor optical amplifier(SOA) as a gain medium in an internal fiber ring cavity. The light deriving from one port of the SOA goes through an optical isolator, the AOTF, a fiber coupler and a polarized controller successively, then it goes back to the other port of the SOA to form a ring cavity. The laser output is from another port of the fiber coupler. The laser made by this method is mainly used for swept-source optical ...
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19. System and method for interlacing differing coherence length sweeps to improve OCT image quality
  
  Explore uspto.gov Nov 1 2016 Patents , Tunable Sources
  
  A system and method for sweeping electromagnetic radiation over a first coherence length and a second length over a range of wavelengths to generate an image. Electromagnetic radiation having a first coherence length is generated and swept over a range of wavelengths. Electromagnetic radiation having a second coherence length is generated and swept over a range of wavelengths. The electromagnetic radiation is splitting through a reference path and a sample path; Electromagnetic radiation returned from the reference path and the sample path is detected, wherein the detector generates output signals corresponding to the received electromagnetic radiation. In one embodiment, the ...
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  Mentions: Thomas E. Milner Michael P. Minneman Insight Photonic Solutions
20. Long-range and wide field of view optical coherence tomography for in vivo 3D imaging of large volume object based on akinetic programmable swept source
  
  Explore OSA | OSA Publishing Oct 27 2016 Tunable Sources
  
  Current optical coherence tomography (OCT) imaging suffers from short ranging distance and narrow imaging field of view (FOV). There is growing interest in searching for solutions to these limitations in order to expand further in vivo OCT applications. This paper describes a solution where we utilize an akinetic swept source for OCT implementation to enable ~10 cm ranging distance, associated with the use of a wide-angle camera lens in the sample arm to provide a FOV of ~20 x 20 cm 2 . The akinetic swept source operates at 1300 nm central wavelength with a bandwidth of 100 nm. We propose ...
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  Mentions: University of Washington Ruikang K. Wang
21. Optimization of a dispersion-tuned wavelength-swept fiber laser for optical coherence tomography
  
  Explore OSA | OSA Publishing Sep 19 2016 Tunable Sources
  
  We optimized parameters of a dispersion-tuned wavelength-swept fiber laser by numerically analyzing dynamic characteristics. The optimized laser is experimentally demonstrated and applied to the swept-source optical coherence tomography (SS-OCT) system. The dispersion-tuned wavelength-swept laser (DT-WSL) is a unique tunable fiber laser, whose lasing wavelength can be tuned rapidly without any mechanical tunable filters. Although the wavelength of a DT-WSL can be swept rapidly and widely, the broadening of the instantaneous spectral width at a high sweep rate has been a critical drawback for SS-OCT applications. Numerical simulations have shown that higher modulation frequencies for active mode-locking lead to narrower instantaneous ...
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  Mentions: University of Tokyo
22. Regenerative mode locked laser swept source for OCT medical imaging
  
  Explore uspto.gov Sep 13 2016 Patents , Tunable Sources
  
  An optical coherence analysis system uses a laser swept source that is constrained to operate in a mode locked condition using regenerative mode-locking. This is accomplished by synchronously changing the laser cavity's net gain and/or phase based on time varying intensity of the swept optical signal generated by the laser. This produces a stable pulsation behavior, which is associated with smooth tuning (low optical frequency reference clock jitter) and low relative intensity noise (RIN).
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  Mentions: Axsun Technologies Bart Johnson
23. Wavelength tunable photon source with sealed inner volume
  
  Explore uspto.gov Sep 6 2016 Patents , Tunable Sources
  
  There is presented a method of providing a wavelength tunable photon source (200), comprising bonding a first element (101) with a first mirror (106), a second element (102) with a second mirror (108) and a third element (103) with a photon emitter together in a structure enclosing an inner volume (214) being a sealed volume, and forming a bonding interface (212) which is gas-tight, so that the first mirror (106) is placed in the inner volume (214) so the first mirror (106) may move within the inner volume (214). The method provides a relatively simple way of obtaining a tunable ...
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  Mentions: Technical University of Denmark (DTU)
24. Surface emitting laser having a factor of equivalent refractive index constraint by scaled central wavelengths and optical coherence tomography apparatus equipped with such surface emitting laser
  
  Explore uspto.gov Aug 30 2016 Patents , Tunable Sources
  
  $Surface emitting laser having a factor of equivalent refractive index constraint by scaled central wavelengths and optical coherence tomography apparatus equipped with such surface emitting laser$
  A surface emitting laser according to the present invention includes a lower reflector, a first spacer layer, an active layer, a second spacer layer composed of a semiconductor material, a gap section formed of at least one of vacuum and gas, and an upper reflector in the written order, and also includes a control mechanism that changes a distance between an interface between the second spacer layer and the gap section and an interface between the upper reflector and the gap section. An optical path length n.sub.eff.times.d extending from an interface between the lower reflector and ...
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  Mentions: Canon Medical Systems
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