Tunable Sources -Optical Coherence Tomography News

Articles in category: Tunable Sources

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1. 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
2. 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
3. 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
4. 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
5. 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
6. 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
7. 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
8. 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
9. 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
10. 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
11. 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
12. 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
13. 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
14. 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
15. High-speed ultra-broad tuning MEMS-VCSELs for imaging and spectroscopy
  
  Explore Conference Proceedings May 21 2013 Tunable Sources
  
  In the last 2 years, the field of micro-electro-mechanical systems tunable vertical cavity surface-emitting lasers (MEMS-VCSELs) has seen dramatic improvements in laser tuning range and tuning speed, along with expansion into unexplored wavelength bands, enabling new applications. This paper describes the design and performance of high-speed ultra-broad tuning range 1050nm and 1310nm MEMS-VCSELs for medical imaging and spectroscopy. Key results include achievement of the first MEMS-VCSELs at 1050nm and 1310nm, with 100nm tuning demonstrated at 1050nm and 150nm tuning at shown at 1310nm. The latter result represents the widest tuning range of any MEMS-VCSEL at any wavelength. Wide tuning range ...
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  Mentions: University of Wisconsin Massachusetts Institute of Technology James G. Fujimoto
16. Picosecond pulses from wavelength-swept continuous-wave Fourier domain mode-locked lasers
  
  Explore Nature Publishing Group May 16 2013 Tunable Sources
  
  Ultrafast lasers have a crucial function in many fields of science; however, up to now, high-energy pulses directly from compact, efficient and low-power semiconductor lasers are not available. Therefore, we introduce a new approach based on temporal compression of the continuous-wave, wavelength-swept output of Fourier domain mode-locked lasers, where a narrowband optical filter is tuned synchronously to the round-trip time of light in a kilometre-long laser cavity. So far, these rapidly swept lasers enabled orders-of-magnitude speed increase in optical coherence tomography. Here we report on the generation of ~60-70 ps pulses at 390 kHz repetition rate. As energy is stored ...
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  Mentions: Robert A. Huber Wolfgang Wieser Thomas Klein
17. Swept source OCT apparatus
  
  Explore uspto.gov May 14 2013 Patents , Tunable Sources
  
  A method of performing spectral OCT imaging on a target involves repeatedly scanning said target along a transverse scanning line with an object beam derived from an OCT interferometer having a narrowband source. The wavelength of the narrowband source is modulated over a range of wavelengths at a rate that is slow relative to the rate of scanning the target. The object beam returned from the target is detected to produce a set of data obtained from multiple scans along said scanning line over the entire range of wavelengths. The data is then processed to extract an OCT image (typically ...
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  Mentions: John A. Rogers Optos
18. Visual perception enhancement for detection of cancerous oral tissue by multi-spectral imaging
  
  Explore IOPscience Mar 7 2013 Oncology , Tunable Sources
  
  Color reproduction systems based on the multi-spectral imaging technique (MSI) for both directly estimating reflection spectra and direct visualization of oral tissues using various light sources are proposed. Images from three oral cancer patients were taken as the experimental samples, and spectral differences between pre-cancerous and normal oral mucosal tissues were calculated at three time points during 5-aminolevulinic acid photodynamic therapy (ALA-PDT) to analyze whether they were consistent with disease processes. To check the successful treatment of oral cancer with ALA-PDT, oral cavity images by swept source optical coherence tomography (SS-OCT) are demonstrated. This system can also reproduce images under ...
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  Mentions: National Taiwan University Meng-Tsan Tsai Chang Gung University
19. System and method for correcting sampling errors associated with radiation source tuning rate fluctuations in swept-wavelength interferometry
  
  Explore uspto.gov Mar 5 2013 Patents , Tunable Sources
  
  The frequency-sampling method is widely used to accommodate nonlinear electromagnetic source tuning in swept-wavelength interferometric techniques, such as optical frequency domain reflectometry (OFDR) and swept-wavelength optical coherence tomography (OCT). Two sources of sampling errors are associated with the frequency-sampling method. One source of error is the limit of an underlying approximation for long interferometer path mismatches and fast electromagnetic source tuning rates. A second source of error is transmission delays in data acquisition hardware. Aspects of the invention relate to a method and system for correcting sampling errors in swept-wavelength interferometry systems such that the two error sources correct sampling ...
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  Mentions: University of Colorado
20. Algorithm for Excitation Optimization of Fabry-Perot Filters Used in Swept Sources
  
  Explore IEEE Xplore Feb 19 2013 Tunable Sources
  
  We investigate the improvement in the nonlinearity of a conventional wavelength swept laser source on the basis of a fiber Fabry–Pérot tunable filter using a well-established optimization method, simulated annealing (SA). The signal driving the filter is constructed from many short ramps of different slopes that are interconnected. The values of the slopes are optimized through the SA algorithm to achieve maximum amplitude for the Fourier transformed peaks of the photodetected interferometric signal.
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  Mentions: Adrian G. Podoleanu University of Kent Multiwave Photonics
21. Hamamatsu's New Medical Light Source using NTT's Communication Laser Technology
  
  Explore hamamatsu.com Feb 19 2013 Other Business News , Tunable Sources
  
  In a joint partnership, NTT Advance Technology Corp. (hereinafter: NTT-AT; head office: Shinjuku-ku, Tokyo; President and CEO: Takashi Hanazawa) and Hamamatsu Photonics K.K. (head office: Hamamatsu-shi, Shizuoka; President and CEO: Akira Hiruma) will start selling a 1.3-μm-band wavelength swept light source for use in optical coherence tomography (OCT) on February 1. OCT is a non-invasive in vivo imaging technique that is widely used in clinical applications. NTT-AT has developed this product using the same technology employed in the manufacture of an electro-optic crystal called KTN (potassium tantalate niobate: KTa 1-x Nb x O 3 ) developed for use ...
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  Mentions: Hamamatsu Photonics NTT
22. ams Technologies 200 kHz Swept Light Source for OCT Imaging
  
  Explore Home - AMS Technologies Feb 18 2013 Other Business News , Tunable Sources
  
  High-speed lightwave sweep enabling high-speed, high-resolution imaging – New Laser Technology reduces the impact of diagnostic imaging on patients The newly developed light source uses a high-speed KTN light deflector and high-speed wavelength swept variable laser technology, both developed by NTT for used in telecommunications. This is currently the fastest light source commercially available. The wavelength used is in the 1.3 μm band, the band used for OCT-based examination of the coronary arteries. In addition to the high-speed sweep at 200 kHz, the product has the following performance features: - wavelength sweep span larger than 100 nm - average light output of ...
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  Mentions: NTT
23. Optimization of Excitation of Fiber Fabry-Perot Tunable Filters Used In Swept Sources for Optical Coherence Tomography Using Simulated Annealing Algorithm
  
  Explore IEEE Xplore Jan 22 2013 Tunable Sources
  
  We investigate the improvement in the nonlinearity of a conventional wavelength swept laser source based on a fiber Fabry-Perot tunable filter using a well established optimization method, simulated annealing (SA). The signal driving the filter is constructed from many short ramps of different slopes that are connected to each other. The values of the slopes are optimised using the SA algorithm in order to achieve maximum amplitude for the Fourier transformed peaks of the photodetected interferometric signal.
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  Mentions: Adrian G. Podoleanu Adrian Bradu Antonio Lobo
24. New Exalos Swept-Source OEM Module - Visit our SS-OCT engine demonstration at Photonics West 2013!
  
  Explore Optical Coherence Tomography News Jan 22 2013 Other Business News , Tunable Sources
  
  Exalos Press Release - EXALOS AG, in response to our valuable swept source customers requiring an industrial solution addressing small form factor, volume scalability, and cost effectiveness, announces the introduction of its new compact swept source OEM module and the demonstration of a high-performance swept source. The robust and compact swept-source OEM module integrates the miniature swept source in a 26-PIN butterfly (BTF) package with the associated drive electronics, resulting in a 3.5” HDD format perfect for broad-base field deployment of OCT imaging and sensing applications. A 1310-nm swept source operating at 40 kHz A-scan rate is realized in a ...
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  Mentions: Exalos Kevin Hsu
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