Tunable Sources -Optical Coherence Tomography News

Articles in category: Tunable Sources

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1. Single longitudinal mode Ytterbium doped fiber lasers with large proposed tuning range
  
  Explore Home - Springer Feb 20 2014 Tunable Sources
  
  A 1,064 nm band Ytterbium doped fiber laser (YDFL) is proposed and investigated. Using 70 cm gain fiber and recycling pumping scheme, a high slope efficiency of 50 % and low threshold power of 53 mW are obtained. The power variation is less than 0.1 dB in 13 nm tuning span. Using the Vernier effect, near single frequency lasing is realized for the whole tuning range in 2 dBm output power. Have advantages of simpler structure, larger pump slope efficiency and possible shorter cavity, the YDFL may find potential applications in various ways.
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  Mentions: National Taiwan University
2. A rapid, dispersion-based wavelength-stepped and wavelength-swept laser for optical coherence tomography
  
  Explore opticsinfobase.org Feb 5 2014 Tunable Sources
  
  Abstract: Optical-domain subsampling enables Fourier-domain OCT imaging at high-speeds and extended depth ranges while limiting the required acquisition bandwidth. To perform optical-domain subsampling, a wavelength-stepped rather than a wavelength-swept source is required. This preliminary study introduces a novel design for a rapid wavelength-stepped laser source that uses dispersive fibers in combination with a fast lithium-niobate modulator to achieve wavelength selection. A laser with 200 GHz wavelength-stepping and a sweep rate of 9 MHz over a 94 nm range at a center wavelength of 1550 nm is demonstrated. A reconfiguration of this source design to a continuous wavelength-swept light for conventional ...
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  Mentions: Massachusetts General Hospital Harvard University Benjamin J. Vakoc
3. Akinetic all-semiconductor programmable swept-source at 1550 nm and 1310 nm with centimeters coherence length
  
  Explore opticsinfobase.org Feb 3 2014 Tunable Sources
  
  We demonstrate, for the first time, OCT imaging capabilities of a novel, akinetic (without any form of movement in the tuning mechanism), all-semiconductor, all-electronic tunable, compact and flexible swept source laser technology at 1550 nm and 1310 nm. To investigate its OCT performance, 2D and 3D ex vivo and in vivo OCT imaging was performed at different sweep rates, from 20 kHz up to 200 kHz, with different axial resolutions, about 10 µm to 20 µm, and at different coherence gate displacements, from zero delay to >17 cm. Laser source phase linearity and phase repeatability standard deviation of <2 mrad ...
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  Mentions: Rainer A. Leitgeb Wolfgang Drexler Medical University of Vienna
4. Axsun Technologies Announces Volume Purchase Order for Swept Laser Engines from Michelson Diagnostics Ltd.
  
  Explore Optical Coherence Tomography News Feb 3 2014 Other Business News , Tunable Sources
  
  Axsun Technologies, Inc., a wholly-owned subsidiary of Volcano Corporation ( VOLC ) and a leading developer and manufacturer of advanced photonic components and subsystems, has received a volume purchase order for Swept Laser OCT Engines from Michelson Diagnostics Ltd. The Axsun Swept Laser OCT Engine will power the new Michelson Diagnostics' Vivosight Multi-Beam OCT system. The Vivosight Multi-Beam OCT system is the first OCT scanner to receive FDA 510(k) clearance for imaging skin in high definition, revealing subsurface tissue structure at unprecedented detail. "Axsun's Swept Laser OCT Engines are ideally suited for real-time OCT imaging in many imaging applications," said ...
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  Mentions: Michelson Diagnostics Axsun Technologies Jon Holmes
5. Feature Of The Week 2/2/14: Tsinghua University.Demonstrates Linear-in-Wavenumber Swept Laser with an Acousto-Optic Deflector for OCT
  
  Explore Optical Coherence Tomography News Feb 2 2014 Tunable Sources
  
  Compared to the conventional time domain OCT, the frequency domain (FD) detection techniques enable a dramatic increase in imaging speed. Spectrometer-based FD-OCT (SD-OCT) systems are already widely used, especially for ophthalmic application in the 800 nm wavelength range. Alternatively, the application of FD-OCT systems based on a rapidly swept, narrowband light source, i.e. swept source OCT (SS-OCT) offers the additional advantages of dual balance detection, potentially longer ranging depth and higher imaging speeds. However, a general disadvantage of most FD-OCT systems is the requirement to resample and recalibrate the detected OCT interference fringe prior to fast Fourier transformation, in ...
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  Mentions: Tsinghua University Ping Xue Jing-gao Zheng
6. Axsun’s New Lead-Free Tunable Laser Platform Meets Requirements of ROHS2 Directive
  
  Explore Optical Coherence Tomography News Jan 31 2014 Other Business News , Tunable Sources
  
  Axsun Technologies Inc., a wholly-owned subsidiary of Volcano Corporation and a leading developer and manufacturer of advanced photonic components and subsystems, has announced the Qualification of their new Lead-Free Tunable Laser packaging platform. Axsun's new Lead-Free platform provides the same performance and reliability as previous generations and meets the requirements of the Reduction of Hazardous Substances (ROHS) Directive 2011/65/EU (also known as ROHS2). This new directive eliminates exemptions for several product categories, including Medical Devices that were present in the 2002 Directive. Axsun will begin sampling new Lead-Free Engines in May 2014. "Axsun's Swept Laser OCT ...
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  Mentions: Axsun Technologies Volcano Corporation
7. Refining imaging strategies to enhance understanding of congenital anomalies
  
  Explore Home: SPIE.org Jan 28 2014 Cardiology , Tunable Sources
  
  Optical coherence tomography in live animal models offers dynamic imaging capabilities for analyzing how aberrant morphologies and other birth defects occur during embryogenesis. Studying the mechanisms that regulate normal and abnormal development in murine (mouse) embryos can yield deeper insights into how and why anomalies sometimes appear. A great deal of knowledge can be gained from imaging studies of murine cells, tissues, and organs during early development that could ultimately lead to improved strategies for the prevention and treatment of birth defects in humans. In the past, such imaging has involved tissue staining to enable researchers to visualize cellular development ...
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  Mentions: National Institutes of Health Baylor College of Medicine Kirill V. Larin
8. Simultaneous Dual-Band Wavelength-Swept Fiber Laser Based on Active Mode Locking
  
  Explore IEEE Xplore Jan 6 2014 Tunable Sources
  
  We report a simultaneous dual-band wavelength-swept laser based on the active mode locking method. By applying a single modulation signal, synchronized sweeping of two lasing-wavelengths is demonstrated without the use of a mechanical wavelength-selecting filter. Two free spectral ranges are independently controlled with a dual path-length configuration of a laser cavity. The static and dynamic performances of a dual-band wavelength-swept active mode locking fiber laser are characterized in both the time and wavelength regions. Two lasing wavelengths were swept simultaneously from 1263.0 to 1333.3 nm for the 1310 nm band and from 1493 to 1563.3 nm for ...
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  Mentions: Zhongping Chen Myung Yung Jeong Chang-Seok Kim
9. Linear-in-wavenumber swept laser with an acousto-optic deflector for optical coherence tomography
  
  Explore opticsinfobase.org Jan 3 2014 Tunable Sources
  
  We report a novel linear-in-wavenumber ( k -linear) swept laser source based on an acousto-optic deflector (AOD). The AOD-based optical filter includes an acousto-optic deflector and a reflection grating. The laser may tune k linearly in wavenumber over time due to its appropriate configuration and is favorable for fast imaging because it avoids data resampling and recalibration, as are required in conventional swept source optical coherence tomography (SS-OCT). We achieved k -linearity with Pearson’s r correlation coefficients of 0.99995 without and 0.99997 with optimization. The laser has a tuning range of 50 nm, a 3 dB swept range ...
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  Mentions: Tsinghua University Ping Xue Jing-gao Zheng
10. Deeply-Etched Optical MEMS Tunable Filter for Swept Laser Source Applications
  
  Explore IEEE Xplore Dec 16 2013 Tunable Sources
  
  In this letter, we report a wide tuning range MEMS-based swept laser source using deep reactive ion etching on an SoI substrate. A MEMS Fabry–Pérot filter with a free-spectral range 105nm and a tuning range wider than 94 nm is presented. The measured transmission loss of the filter is between 10.2 and 13.6 dB . This filter is used to construct a swept laser source with 85 nm tuning range. These results represent the widest tuning range reported in literature for an in-plane SoI-MEMS based swept laser source using deeply-etched free-standing distributed-Bragg-reflection mirrors. The recorded tuning range ...
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  Mentions: Haitham Omran
11. Feature Of The Week 12/8/2013: Tuning of Vernier Tuned DBR Lasers for Optical Comb Swept Source OCT
  
  Explore Optical Coherence Tomography News Dec 8 2013 Tunable Sources
  
  Monolithic Vernier tuned distributed Bragg reflector (VT-DBR) lasers are expected to become one of the most promising sources for optical comb swept source optical coherence tomography (SS-OCT) with reduced sensitivity roll-off due to a long coherence length, potential capability for a very fast A-scan rate, and low cost with monolithic structure. However, mainly four problems inhibited an ideal implementations: 1) frequencies deviate from the targeted values when scanned, 2) large amounts of noise appear associated with abrupt changes in injection currents, 3) optically aliased noise appears due to a long coherence length, and 4) the narrow wavelength coverage of a ...
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  Mentions: Kohji Ohbayashi Kitasato University Advanced Imaging Company Ltd
12. Swept-frequency semiconductor laser coupled to microfabricated biomolecular sensor and methods related thereto
  
  Explore uspto.gov Dec 3 2013 Patents , Tunable Sources
  
  An optoelectronic swept-frequency semiconductor laser coupled to a microfabricated optical biomolecular sensor with integrated resonator and waveguide and methods related thereto are described. Biomolecular sensors with optical resonator microfabricated with integrated waveguide operation can be in a microfluidic flow cell.
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  Mentions: California Institute of Technology
13. Tuning of successively scanned two monolithic Vernier-tuned lasers and selective data sampling in optical comb swept source optical coherence tomography
  
  Explore opticsinfobase.org Nov 22 2013 Tunable Sources
  
  Monolithic Vernier tuned super-structure grating distributed Bragg reflector (SSG-DBR) lasers are expected to become one of the most promising sources for swept source optical coherence tomography (SS-OCT) with a long coherence length, reduced sensitivity roll-off, and potential capability for a very fast A-scan rate. However, previous implementations of the lasers suffer from four main problems: 1) frequencies deviate from the targeted values when scanned, 2) large amounts of noise appear associated with abrupt changes in injection currents, 3) optically aliased noise appears due to a long coherence length, and 4) the narrow wavelength coverage of a single chip limits resolution ...
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  Mentions: Kohji Ohbayashi Kitasato University
14. WAVELENGTH-VARIABLE Laser Including SOA And Optical Coherence Tomography Apparatus Including The Laser
  
  Explore patentscope.wipo.int Nov 1 2013 Patents , Tunable Sources
  
  Provided is a wavelength-variable laser including an SOA which controls not a shape of a gain spectrum itself in the SOA but a shape of a gain spectrum obtained in the entire SOA to enable inhibition of output fluctuations. The wavelength-variable laser including an SOA includes: a wavelength selection mechanism for selectively reflecting a wavelength; an SOA for amplifying light, the SOA being configured to reflect light that enters a first end facet by a second end facet opposite to the first facet and to cause light amplified in an active layer to exit from the first facet; and a ...
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  Mentions: Canon Medical Systems
15. Akinetic all-semiconductor swept lasers boost OCT image quality
  
  Explore Laser Focus World Oct 14 2013 Tunable Sources
  
  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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  Mentions: Wolfgang Drexler Medical University of Vienna Michael P. Minneman
16. PhD scholarship in MEMS Tunable VCSELs for Long Wavelength Sensing at Technical University of Denmark
  
  Explore Optical Coherence Tomography News Oct 3 2013 Tunable Sources , Jobs & Studentships
  
  Applications are invited for a 3-year PhD position within the field of MEMS tunable VCSELs for long wavelength sensing. The project is multidisciplinary and will cover topics within the field of semiconductor optical devices, microelectromechanical systems, semiconductor technology and optical measurement systems. The project will be carried out at the Department of Photonics, Technical University of Denmark (DTU). Project description Fast and widely tunable VCSELs are set to revolutionize the applications of tunable lasers for sensing. They promise not only low cost but also new properties like high dynamic coherence not normally associated with fast tunable lasers. Impressive results have ...
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  Mentions: James G. Fujimoto Technical University of Denmark (DTU) Benjamin M. Potsaid
17. MULTI-SPEED Oct Swept Source With Optimized K-CLOCK
  
  Explore patentscope.wipo.int Oct 1 2013 Patents , Tunable Sources
  
  An optical coherence tomography system utilizes an optical swept source that frequency scans at least two different sweep rates. In this way, the system can perform large depth scans of the sample and then the same system can perform shorter depth high precision scans, in one specific example.
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  Mentions: Axsun Technologies Volcano Corporation Dale Flanders
18. ASE swept source with self-tracking filter for OCT medical imaging
  
  Explore uspto.gov Sep 3 2013 Patents , Tunable Sources
  
  An integrated swept wavelength tunable optical source uses a narrowband filtered broadband signal with an optical amplifier and self-tracking filter. This source comprises a micro optical bench, a source for generating broadband light, a tunable Fabry Perot filter, installed on the bench, for spectrally filtering the broadband light from the broadband source to generate a narrowband tunable signal, an amplifier, installed on the bench, for amplifying the tunable signal. The self-tracking arrangement is used where a single tunable filter both generates the narrowband signal and spectrally filters the amplified signal. In some examples, two-stage amplification is provided. The use of ...
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  Mentions: Axsun Technologies Volcano Corporation Dale Flanders
19. In Vivo OCT Imaging Based on La-Codoped Bismuth-Based Erbium-Doped Fiber
  
  Explore IEEE Xplore Aug 15 2013 Tunable Sources
  
  We demonstrate a Fourier domain mode-locked laser based on lanthanum-codoped bismuth-based erbium-doped fiber (Bi-EDF) for swept source optical coherence tomography (SS-OCT) imaging. Raman amplification is incorporated to suppress the gain competition and homogenous linewidth broadening effects of Bi-EDF. A wavelength sweeping bandwidth of 81 nm is generated under stable operation. Therefore, in vivo OCT imaging of human finger print and orange slices is enabled and the results are also presented. This scheme paves the way for doped fiber amplifiers to be employed to generate ultra-wideband SSs for OCT applications.
  
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  Mentions: University of Hong Kong
20. Three-dimensional high-speed optical coherence tomography system using KTN swept light source
  
  Explore IEEE Xplore Aug 5 2013 Tunable Sources
  
  Three-dimensional (3D) optical coherence tomography (3D-OCT) has attracted attention for visualising complex structures in the biomedical field. In this reported work, a high-speed 3D-OCT system is developed, which is based on a high-speed swept light source and aMach-Zehnder interferometer with a high-speed photodetector. The light source, incorporating a KTa 1-x Nb x O 3 electro-optic deflector, operates at a repetition rate of 200 kHz and enables high-speed data acquisition. As a preliminary study, images of a strawberry's surface have been obtained, two- and three-dimensionally. The 3D-OCT system has potential for the construction of a four-dimensional OCT image to dynamically ...
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  Mentions: NTT Osaka University Taiji Sakamoto
21. Characterization and Modeling of an O-Band 1310 nm Sampled-Grating Distributed Bragg Reflector (SG-DBR) Laser for Optical Coherence Tomography (OCT) Applications (Thesis)
  
  Explore DigitalCommons@CalPoly Aug 1 2013 Tunable Sources , Student Theses
  
  In this project, the performance aspects of a new early generation 1310 nm Sampled-Grating Distributed Bragg Reflector (SG-DBR) semiconductor laser are investigated. SG-DBR lasers are ideal for Source Swept Optical Coherence Tomography (SS-OCT), a Fourier-Domain based approach for OCT, necessitating a tunable wavelength source. Three internal sections control the frequency output for tuning, along with two amplifiers for amplitude control. These O-band SG-DBR devices are now being produced in research quantities. SG-DBR lasers have been produced at 1550 and 1600 nm for some times. Fundamental questions regarding the performance of the 1310 nm devices must be quantified. Standard metrics including ...
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  Mentions: Dennis Derickson
22. High-Speed Optical Coherence Tomography System Using a 200-kHz Swept Light Source with a KTN Deflector
  
  Explore scirp.org Jun 14 2013 Tunable Sources
  
  We demonstrate a high-speed swept-source optical coherence tomography (SS-OCT) system, which is based on a high- speed swept light source and a Mach-Zehnder interferometer with a high-speed photodetector. The light source is an external-cavity laser tuned by a KTN electro-optic deflector, which exhibits a very fast response and large deflection. The scanning wavelength range is almost 80 nm up to 200 kHz with a ±400-V deflector driving voltage. The system acquires 1 mm × 1 mm images consisting of 200 × 200 pixels within few milliseconds. We present preliminary SS-OCT images of an in-vitro human nail and an in-vivo finger pad.
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  Mentions: NTT Osaka University
23. A Fourier domain mode-locked fiber laser based on dual-pump fiber optical parametric amplification and its application for a sensing system
  
  Explore IOPscience Jun 11 2013 Tunable Sources
  
  A Fourier domain mode-locked (FDML) fiber laser based on dual-pump fiber optical parametric amplification (FOPA) is proposed and demonstrated. The output spectrum of the proposed FDML fiber laser covers a sweeping wavelength range from 1540.8 to 1559.8 nm with a sweeping frequency of 31.688 kHz. A comparison of two FDML fiber lasers which are based on dual-pump FOPA and one-pump FOPA is also presented. A novel sensing system based on the FDML laser and a fiber Bragg grating, by which the sensing signal can be measured in the time domain instead of the frequency domain, is also ...
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  Mentions: Zhejiang University
24. Reproducibility of a Long-Range Swept-Source Optical Coherence Tomography Ocular Biometry System and Comparison with Clinical Biometers - Corrected Proof
  
  Explore Ophthalmology Jun 4 2013 Ophthalmology , Tunable Sources
  
  Objective: To demonstrate a novel swept source optical coherence tomography (SS-OCT) imaging device using a vertical cavity surface-emitting laser (VCSEL) capable of imaging the full eye length and to introduce a method using this device for noncontact ocular biometry. To compare the measurements of intraocular distances using this SS-OCT instrument with commercially available optical and ultrasound biometers. To evaluate the intersession reproducibility of measurements of intraocular distances using SS-OCT.Design: Evaluation of technology.Participants: Twenty eyes of 10 healthy subjects imaged at the New England Eye Center at Tufts Medical Center and Massachusetts Institute of Technology between May and September ...
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  Mentions: Massachusetts Institute of Technology Thorlabs Carl Zeiss Meditec
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