Tunable Sources -Optical Coherence Tomography News

Articles in category: Tunable Sources

1-24 of 327 1 2 3 4 ... 12 13 14 »
1. 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 ...
  Read Full Article
  
  Comment
  
  Mentions: University of Tokyo
2. 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).
  Read Full Article
  
  Comment
  
  Mentions: Axsun Technologies Bart Johnson
3. 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 ...
  Read Full Article
  
  Comment
  
  Mentions: Technical University of Denmark (DTU)
4. 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 ...
  Read Full Article
  
  Comment
  
  Mentions: Canon Medical Systems
5. Amplified widely tunable short cavity laser
  
  Explore uspto.gov Aug 9 2016 Patents , Tunable Sources
  
  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 optical filters with the amplified tunable source to reduce noise or improve spectral purity are presented.
  Read Full Article
  
  Comment
  
  Mentions: Thorlabs Alex E. Cable Benjamin M. Potsaid
6. Tunable short cavity laser sensor
  
  Explore uspto.gov Jul 19 2016 Patents , Tunable Sources
  
  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.
  Read Full Article
  
  Comment
  
  Mentions: Thorlabs Alex E. Cable Benjamin M. Potsaid
7. Polarization stable widely tunable short cavity laser
  
  Explore uspto.gov Jul 12 2016 Patents , Tunable Sources
  
  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.
  Read Full Article
  
  Comment
  
  Mentions: Thorlabs Alex E. Cable Praevium Research
8. System and method for generating and utilizing a valid sweep signal to obviate spurious data and increase sweep rate in an akinetic path-based swept laser
  
  Explore uspto.gov Jul 5 2016 Patents , Tunable Sources
  
  A system and method for triggering data acquisition in a semiconductor laser system including outputting electromagnetic energy from the semiconductor laser over a range of wavelengths according to a signaling path. The signaling path includes a plurality of discrete data inputs to the semiconductor laser for outputting electromagnetic energy over a range of wavelengths and the signaling path includes one or more perturbances in transitioning from one wavelength to another wavelength along the signaling path. A series of triggering signals for input to a measurement system is generated by the semiconductor laser. The semiconductor laser also generates a series of ...
  Read Full Article
  
  Comment
  
  Mentions: Michael P. Minneman Insight Photonic Solutions
9. Tunable Emission Wavelength Stacked InAs/GaAs Quantum Dots by Chemical Beam Epitaxy for Optical Coherence Tomography
  
  Explore MDPI Open Access Journals Platform Jun 28 2016 Tunable Sources
  
  We report on Chemical Beam Epitaxy (CBE) growth of wavelength tunable InAs/GaAs quantum dots (QD) based superluminescent diode’s active layer suitable for Optical Coherence Tomography (OCT). The In-flush technique has been employed to fabricate QD with controllable heights, from 5 nm down to 2 nm, allowing a tunable emission band over 160 nm. The emission wavelength blueshift has been ensured by reducing both dots’ height and composition. A structure containing four vertically stacked height-engineered QDs have been fabricated, showing a room temperature broad emission band centered at 1.1 µm. The buried QD layers remain insensitive to the ...
  Read Full Article
  
  Comment
10. Wavelength swept light source
  
  Explore uspto.gov Jun 21 2016 Patents , Tunable Sources
  
  A wavelength swept light source includes a sawtooth waveform as a main waveform and an exponential component of the sawtooth waveform to the controlled voltage of the electro-optic deflector. The controlled voltage is controlled so that, as an oscillation wavelength to be swept is swept towards a longer wavelength side, a change rate of the oscillation wavelength is increased.
  Read Full Article
  
  Comment
  
  Mentions: NTT
11. Master/slave interferometry – ideal tool for coherence revival swept source optical coherence tomography
  
  Explore OSA | OSA Publishing Jun 3 2016 Tunable Sources
  
  In this paper, we demonstrate that the master slave (MS) interferometry method can significantly simplify the practice of coherence revival swept source optical coherence tomography (OCT) technique. Previous implementations of the coherence revival technique required considerable resources on dispersion compensation and data resampling. The total tolerance of the MS method to nonlinear tuning, to dispersion in the interferometer and to dispersion due to the laser cavity, makes the MS ideally suited to the practice of coherence revival. In addition, enhanced versatility is allowed by the MS method in displaying shorter axial range images than that determined by the digital sampling ...
  Read Full Article
  
  Comment
  
  Mentions: Adrian G. Podoleanu University of Kent Adrian Bradu
12. Swept source optical coherence tomography and method for stabilizing phase thereof
  
  Explore uspto.gov May 31 2016 Patents , Tunable Sources
  
  In an embodiment, a computer 16, which generates tomographic images based on spectral interference signals detected by a light detector 15 from overlaid reference light emitted by a swept-source type light source 2 of a SS-OCT, split, and then reflected by a fixed reference mirror 8 on one hand and object light reflected by an object to be measured 6 on the other, is caused to function to apply rough correction using a first correction means and then apply detailed correction using a second correction means, to stabilize the phases of the SS-OCT. The phases can be stabilized by eliminating ...
  Read Full Article
  
  Comment
  
  Mentions: Yoshiaki Yasuno University of Tsukuba
13. SNR of swept SLEDs and swept lasers for OCT
  
  Explore OSA | OSA Publishing May 14 2016 Tunable Sources
  
  A back-to-back comparison of a tunable narrow-band-filtered SLED (TSLED) and a swept laser are made for OCT applications. The two sources are similar in terms of sweep speed, tuning range and coherence length. A fundamental issue with a TSLED is that the RIN is proportional to 1/linewidth, meaning that the longer the coherence length, the higher the RIN and clock jitter. We show that the TSLED has an SNR limit that causes noise streaks at points of high reflection in images. The laser, which is shot noise limited, does not exhibit this effect. We add noise terms proportional to ...
  Read Full Article
  
  Comment
  
  Mentions: Axsun Technologies Dale Flanders Brian D. Goldberg
14. IEEE Boston Photonics Society Talk on Swept Source Lasers by Bart Johnson
  
  Explore BostonPhotonics.org Apr 29 2016 Tunable Sources
  
  The development of swept source lasers has made high-speed optical coherence tomography (OCT) cost effective at 1060 and 1310 nm wavelengths. Axsun Technologies manufactures this type of source and has made inroads into ophthalmology and cardiology applications. The 1060 product, for example, tunes 990-1100 nm at a 100 kHz sweep rate. This external cavity diode laser is tuned by a MEMS Fabry-Perot filter. The act of rapidly sweeping the filter induces a mode-locking behavior. This is because when the pulses deplete the gain medium they are red shifted due to the index rise in the semiconductor optical amplifier associated with ...
  Read Full Article
  
  Comment
  
  Mentions: Axsun Technologies Bart Johnson
15. Surface emitting laser and optical coherence tomography apparatus including the same
  
  Explore uspto.gov Apr 19 2016 Patents , Tunable Sources
  
  A surface emitting laser includes a lower reflector, an active layer, and an upper reflector that are arranged in that order; an air gap provided between the active layer and the upper reflector; and a slab provided on an optical path of the air gap and having a refractive index that is higher than a refractive index of the air gap. A position of at least one of the upper reflector and the lower reflector in an optical axis direction is changed to change a wavelength of emitted light. In the case where the position of the upper reflector is ...
  Read Full Article
  
  Comment
  
  Mentions: Canon Medical Systems
16. Narrow linewidth broadband tunable semiconductor laser at 840 nm with dual acousto-optic tunable configuration for OCT applications
  
  Explore Conference Proceedings Mar 15 2016 Tunable Sources
  
  We demonstrate a tunable narrow linewidth semiconductor laser for the 840 nm spectral range. The laser has a linear cavity comprised of polarization maintaining (PM) fiber. A broadband semiconductor optical amplifier (SOA) in in-line fiber-coupled configuration acts as a gain element. It is based on InGaAs quantum-well (QW) active layer. SOA allows for tuning bandwidth exceeding 25 nm around 840 nm. Small-signal fiber-to-fiber gain of SOA is around 30 dB. A pair of acousto-optic tunable filters (AOTF) with a quasi-collinear interaction of optical and acoustic waves are utilized as spectrally selective elements. AOTF technology benefits in continuous tuning, broadband operation ...
  Read Full Article
  
  Comment
  
  Mentions: Superlum
17. Coherence properties of fast frequency swept lasers revealed via full electric field reconstruction
  
  Explore Conference Proceedings Mar 15 2016 Tunable Sources
  
  A novel, time-resolved interferometric technique is presented allowing the reconstruction of the complex electric field output of a fast frequency swept laser in a single-shot measurement. The power of the technique is demonstrated by examining a short cavity swept source designed for optical coherence tomography applications, with a spectral bandwidth of 18 THz. This novel analysis of the complete electric field reveals the modal structure and modal evolution of the device as well as providing a time-resolved real-time characterization of the optical spectrum, linewidth and coherence properties of a dynamic rapidly swept laser.
  Read Full Article
  
  Comment
  
  Mentions: Maciej Wojtkowski Nicolaus Copernicus University Karol Karnowski
18. Swept-Source optical coherence tomography correlations between retina and choroid before and after vitrectomy for epiretinal membranes
  
  Explore American Journal of Ophthalmology Mar 10 2016 Ophthalmology , Tunable Sources
  
  Purpose To describe retinal and choroidal morphology before and after surgery for epiretinal membranes (ERM) in Swept Source OCT (SS-OCT). Additionally, to evaluate factors responsible for visibility of the suprachoroidal layer (SCL) and suprachoroidal space (SCS). Design Prospective consecutive case series. Material and Methods 29 eyes of 29 patients with symptomatic, idiopathic ERM were included. Pars plana vitrectomy with ERM removal and ILM peeling was performed. We examined patients with SS-OCT twice preoperatively (9-12 months and one week before surgery), then postoperatively at 1 week, 6 and 12 months. Results Twelve months after surgery visual acuity improved to 20/50 ...
  Read Full Article
  
  Comment
  
  Mentions: Jasne Blonia Eye Clinic Janusz Michalewski Jerzy Nawrocki
19. Wavelength-tunable vertical cavity surface emitting laser for swept source optical coherence tomography system
  
  Explore uspto.gov Dec 1 2015 Patents , Tunable Sources
  
  A wavelength-tunable vertical-cavity surface-emitting laser (VCSEL) with the use of microelectromechanical system (MEMS) technology is provided as a swept source for Optical Coherence Tomography (OCT). The wavelength-tunable VCSEL comprises a bottom mirror of the VCSEL, an active region, and a MEMS tunable upper mirror movable by electrostatic deflections. The bottom mirror comprising a GaAs based distributed Bragg reflector (DBR) stack, and the active region comprising multiple stacks of GaAs based quantum dot (QD) layers, are epitaxially grown on a GaAs substrate. The MEMS tunable upper mirror includes a membrane part supported by suspension beams, and an upper mirror comprising a ...
  Read Full Article
  
  Comment
  
  Mentions: InPhenix
20. A New Component Toolbox For 2 Micron Fiber Lasers
  
  Explore Fiber Optics Online Oct 23 2015 Tunable Sources
  
  Gooch & Housego now offers a full suite of passive and active components to enable high power, all-fiber laser systems at 2 µm for use in materials processing, surgery and sensing. Developed over three years during the ISLA project (Integrated disruptive components for 2 µm fiber Lasers), the components draw on G&H core competencies in design and manufacturing of fused fiber components and acousto-optic devices. Fiber lasers have become a workhorse in material processing, where they are valued for their high power, low maintenance, and the convenience of routing light directly to the sample. Most existing fiber lasers operate at ...
  Read Full Article
  
  Comment
  
  Mentions: Gooch & Housego
21. System and method for generating and utilizing sample trigger blanking to obviate spurious data and increase sweep rate in an akinetic path-based swept laser
  
  Explore uspto.gov Oct 6 2015 Patents , Tunable Sources
  
  A system and method for triggering data acquisition in a semiconductor laser system including outputting electromagnetic energy from the semiconductor laser over a range of wavelengths according to a signaling path. The signaling path includes a plurality of discrete data inputs to the semiconductor laser for outputting electromagnetic energy over a range of wavelengths and the signaling path includes one or more perturbances in transitioning from one wavelength to another wavelength along the signaling path. A series of triggering signals are generated for input to a measurement system by the semiconductor laser. The series of triggering signals include a non-uniform ...
  Read Full Article
  
  Comment
  
  Mentions: Michael P. Minneman Insight Photonic Solutions
22. Swept source optical coherence tomography of a vitreal pocket entrapped in myelinated retinal nerve fibers
  
  Explore Home - Springer Oct 4 2015 Ophthalmology , Tunable Sources
  
  No abstract provided
  Read Full Article
  
  Comment
  
  Mentions: San Raffaele Scientfic Institute Francesco Bandello Luisa Pierro
23. New lasers offer low cost industrial processing and novel surgical possibilities
  
  Explore PhysOrg.com Sep 16 2015 Tunable Sources
  
  EU scientists have developed efficient new fibre optic lasers that deliver short wavelengths for accurate polymer material processing, at incredible strength and low cost. The consortium behind the new innovations, developed through the ISLA project, is now in the process of marketing some of these cutting edge devices.
  Read Full Article
  
  Comment
  
  Mentions: University of Vienna University of Southampton
24. VECSELs: Innovative light sources for PDT - Photodiagnosis and Photodynamic Therapy
  
  Explore Photodiagnosis and Photodynamic Therapy Sep 8 2015 Tunable Sources
  
  Photodynamic therapy (PDT) with porphyrins and red light (610–630 nm) is finding increasing clinical application for both the eradication of relatively small tumors and the palliation of inoperable or obstructive tumors. PDT also shows some promise for the sterilization of the tumor bed after surgical removal of neoplastic masses. Optically pumped vertical external-cavity surface-emitting lasers (VECSELs) appear to be a very innovative and efficient technology in this specific wavelength range. Furthermore, VECSELs are power scalable and wavelength tunable, and are an appealing light source for PDT.
  Read Full Article
  
  Comment
  
  Mentions: Mircea Guina
1-24 of 327 1 2 3 4 ... 12 13 14 »