1. Articles in category: Tunable Sources

    1-24 of 429 1 2 3 4 ... 16 17 18 »
    1. Systems, methods, and media for multiple reference arm spectral domain optical coherence tomography

      Systems, methods, and media for multiple reference arm spectral domain optical coherence tomography

      In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled ...

      Read Full Article
    2. MEMS-VCSEL as a tunable light source for OCT imaging of long working distance

      MEMS-VCSEL as a tunable light source for OCT imaging of long working distance

      We present a wavelength tunable vertical-cavity surface-emitting laser (VCSEL) constructed by die-bonding a half-cavity InGaAs laser diode (LD) chip onto a silicon-on-insulator chip with a microelectromechanical system electrostatic diaphragm mirror that functions as a Fabry–Perot interferometer. As a result of the short cavity length, the integrated tunable LD has single-mode lasing characteristics with an extremely large coherence length of 150 m or more. The developed wavelength tunable LD is used to perform swept-source optical coherence tomography with a large scan depth, which is applicable to ophthalmic observation for the diagnosis of pathologic nearsightedness based on the measurement of the ...

      Read Full Article
      Mentions: Santec
    3. Robust and easy-to-operate stretched-pulse mode-locked wavelength-swept laser with an all-polarization-maintaining fiber cavity for 10 MHz A-line rate optical coherence tomography

      Robust and easy-to-operate stretched-pulse mode-locked wavelength-swept laser with an all-polarization-maintaining fiber cavity for 10 MHz A-line rate optical coherence tomography

      We demonstrate robust and easy-to-operate stretched-pulse mode-locked laser (SPML) architectures using all-polarization-maintaining fiber laser cavities. Because of the polarization-maintaining construction, the laser performance is unaffected by mechanical perturbation on the cavity fibers. The lasers automatically initiate linear-in-wavenumber sweeps across 100 nm centered at 1290 nm with a 10 MHz repetition rate. OCT imaging with a sensitivity of 98 dB and a single-sided 6 dB coherence length of 2.5 mm is demonstrated. OCT angiography of a mouse brain that visualized three-dimensional cerebral microvasculature over a field of 1.5 m m × 1.5 m m 1.5mm×1.5mm (398 ...

      Read Full Article
    4. Carl Zeiss Meditec Takes Insight Photonics Solutions to Court for Breach of Contract Seeking $150M in Damages

      Carl Zeiss Meditec Takes Insight Photonics Solutions to Court for Breach of Contract Seeking $150M in Damages

      UNITED STATES DISTRICT COURT SOUTHERN DISTRICT OF NEW YORK CARL ZEISS MEDITEC, INC., Civil Action No. Plaintiff, Complaint v. INSIGHT PHOTONICS SOLUTIONS, INC., Defendant. Plaintiff Carl Zeiss Meditec, Inc. ("Zeiss"), by its attorneys, Dorsey & Whitney LLP, for its Complaint against Defendant Insight Photonics Solutions, Inc. ("Insight"), states as follows: INTRODUCTION 1. This action arises out of Insight's willful and bad faith breaches of a 2017 development agreement (the "Development Agreement") by and among Zeiss, Insight, and a joint venture between Zeiss and Insight, called Ophthalmic Laser Engines, LLC ("OLE"). Under the Development Agreement, Insight was obligated to develop ophthalmic ...

      Read Full Article
    5. Tunable semiconductor slotted lasers for near-infrared Optical Coherence Tomography

      Tunable semiconductor slotted lasers for near-infrared Optical Coherence Tomography

      The use of Optical Coherence Tomography in the field of clinical diagnosis is significant. There are different types of swept source lasers available on the market today, however, their design and associated complex fabrication process increase their cost. In the work presented here, an economical six-section slotted tunable laser operating near 850 nm has been designed and fabricated using a UV optical lithography process. The laser is monolithically integrable without a need for any regrowth step. Initial characterization has confirmed the high quality of the slot geometry and stable single mode operation within its tuning range.

      Read Full Article
    6. Anrtisu Introduces a New Swept Light Source

      Anrtisu Introduces a New Swept Light Source

      Anritsu released the swept light source for OCT applications on 1st July 2021. More information can be found in the following links. https://www.anritsu.com/en-US/sensing-devices/products/swept-light-source Anritsu Wavelength Swept Light Source Operation Principles and OFDR Measurement Application Document Anritsu Wavelength Swept Light Source Measurement Applications Document

      Read Full Article
    7. Wavelength tunable laser device using frequency shifter

      Wavelength tunable laser device using frequency shifter

      A wavelength tunable laser device includes a gain element positioned in an optical cavity that provides optical gain to an optical signal. A frequency shifter that generates a frequency shift as a function of time is positioned in the optical cavity. The optical cavity is configured so that a magnitude of the frequency shift as a function of time generated by the frequency shifter is substantially equal to a frequency separation of a cavity mode of the cavity such that an output of the cavity generates laser light having a wavelength that tunes as a function of time.

      Read Full Article
    8. Cavity length control for Fourier domain mode locked (FDML) lasers with µm precision

      Cavity length control for Fourier domain mode locked (FDML) lasers with µm precision

      In highly dispersion compensated Fourier domain mode locked (FDML) lasers, an ultra-low noise operation can only be achieved by extremely precise and stable matching of the filter tuning period and light circulation time in the cavity. We present a robust and high precision closed-loop control algorithm and an actively cavity length controlled FDML laser. The cavity length control achieves a stability of ∼0.18 mHz at a sweep repetition rate of ∼418 kHz which corresponds to a ratio of 4×10 −10 . Furthermore, we prove that the rapid change of the cavity length has no negative impact on the quality ...

      Read Full Article
    9. Multi-MHz MEMS-VCSEL swept-source optical coherence tomography for endoscopic structural ...

      Multi-MHz MEMS-VCSEL swept-source optical coherence tomography for endoscopic structural ...

      Swept source optical coherence tomography (SS-OCT) enables volumetric imaging of subsurface structure. However, applications requiring wide fields of view (FOV), rapid imaging, and higher resolutions have been challenging because multi-MHz axial scan (A-scan) rates are needed. We describe a microelectromechanical systems vertical cavity surface-emitting laser (MEMS-VCSEL) SS-OCT technology for A-scan rates of 2.4 and 3.0 MHz. Sweep to sweep calibration and resampling are performed using dual channel acquisition of the OCT signal and a Mach Zehnder interferometer signal, overcoming inherent optical clock limitations and enabling higher performance. We demonstrate ultrahigh speed structural SS-OCT and OCT angiography (OCTA) imaging ...

      Read Full Article
    10. Tunable VCSEL polarization control through dissimilar die bonding

      Tunable VCSEL polarization control through dissimilar die bonding

      A design and method for introducing asymmetric crystal strain to control polarization in a tunable VCSEL, either optically or electrically pumped. The invention is especially relevant to wafer- or die-bonded tunable VCSELs. Then, mechanical stress is applied to the half VCSEL device by asymmetric arrangement of metal bond pads.

      Read Full Article
    11. Optically pumped tunable VCSEL employing geometric isolation

      Optically pumped tunable VCSEL employing geometric isolation

      An optically pumped tunable VCSEL swept source module has a VCSEL and a pump, which produces light to pump the VSCEL, wherein the pump is geometrically isolated from the VCSEL. In different embodiments, the pump is geometrically isolated by defocusing light from the pump in front of the VCSEL, behind the VCSEL, and/or by coupling the light from the pump at an angle with respect to the VCSEL. In the last case, angle is usually less than 88 degrees. There are further strategies for attacking pump noise problems. Pump feedback can be reduced through (1) Faraday isolation and (2 ...

      Read Full Article
    12. Introducing the fastest VCSEL Swept Source to market

      Introducing the fastest VCSEL Swept Source to market

      ast 3D imaging with MHz VCSEL Swept Source OCTLIGHT is extending the Caliper product family with the new Caliper-HERO which is the fastest available scalable solution for 3D OCT imaging on the market. It is based on the truly single-mode wavelength tuning VCSEL technology. The patented Highly Efficient Resonant Oscillator (HERO TM ) achieves blazing MHz speeds and single channel acquisition. This pushes the performance that can be achieved in e.g. blood flow imaging, wider field of view imaging and real-time 3D imaging for robotic surgery with a clear path for translation into commercial product benefitting ophthalmologists and patients. Caliper-HERO ...

      Read Full Article
    13. 1.1 μm waveband tunable laser using emission-wavelength-controlled InAs quantum dots for swept-source optical coherence tomography applications

      1.1 μm waveband tunable laser using emission-wavelength-controlled InAs quantum dots for swept-source optical coherence tomography applications

      In this study, an optical gain chip using emission-wavelength-controlled self-assembled InAs quantum dots (QDs) was developed for swept-source optical coherence tomography (SS-OCT) applications. The optical characterizations indicated that the QDs emission wavelength and optical gain spectra were controlled in the 1.1 μ m waveband by optimizing the QDs growth conditions. This waveband is useful for obtaining a large imaging depth of OCT because of an optimal balance between absorption and scattering in biological samples. In addition, continuous tunable lasing in the waveband was achieved by introducing the QD-based gain chip into a grating-coupled external cavity. This tunable laser was introduced ...

      Read Full Article
    14. Method for preserving the synchronism of a Fourier Domain Mode Locked (FDML) laser

      Method for preserving the synchronism of a Fourier Domain Mode Locked (FDML) laser

      The invention relates to a method for maintaining the synchronism of a Fourier Domain Mode Locked (FDML) laser, the FDML laser comprising at least one dispersion-compensated resonator with at least one variably wavelength-selective optical filter, the laser light circulating in the resonator at a circulation frequency, and the wavelength selectivity of the filter being repeatedly modified at a syntonising rate, the FDML laser being synchronous when the syntonising rate is an integral multiple of the circulation frequency. Said method is characterised by the following steps: a) at least a portion of the laser light is coupled out of the resonator ...

      Read Full Article
      Mentions: Optores
    15. Multi-cavity wavelength tunable laser device

      Multi-cavity wavelength tunable laser device

      A wavelength tunable laser device includes a gain element that provides optical gain. A laser cavity includes at least two cavities, wherein each of the at least two cavities has a different optical cavity length. At least two optical modulators are positioned in the laser cavity, wherein the at least two optical modulators are driven with waveforms so as to tune a wavelength of the wavelength tunable laser device.

      Read Full Article
    16. VIS-OCT needs stable, versatile light sources

      VIS-OCT needs stable, versatile light sources

      Optical coherence tomography (OCT) is the gold standard for noninvasive retinal imaging, enabling ophthalmologists to diagnose and treat multiple ocular diseases. Compared to traditional OCT, which uses near-infrared (NIR) wavelengths of light, visible-light OCT (VIS-OCT) offers superior spatial resolution and novel functional imaging capabilities. VIS-OCT provides the most accurate means for measuring retinal oxygen saturation, a key biomarker for understanding changes in tissue metabolism associated with the pathology of various retinal diseases. Traditional OCT has dominated ophthalmic diagnostics for the past 30 years. Thanks to investment in and development of key OCT components, there is an opportunity to accelerate adoption ...

      Read Full Article
    17. PhD Position Available in Lübeck: Development of an Ultra-Wideband FDML-Laser

      PhD Position Available in Lübeck: Development of an Ultra-Wideband FDML-Laser

      We offer a three year PhD student position for an Early Stage Researcher (ESR) on laser development in biomedical optics. The position is part of a Marie Skłodowska-Curie Innovative Training Network (ITN) within the EU Horizon 2020 Framework Programme. It will be within the project NETLAS (https://cordis.europa.eu/project/id/860807), which focuses on innovative solutions for fast, narrow linewidth, phase stable and wide tuning bandwidth swept sources as well as on their application in biomedical optics - especially for optical coherence tomography (OCT). 

      The position is in the group of Robert Huber at the University of Lübeck ...

      Read Full Article
    18. Flexible A-scan rate MHz-OCT: efficient computational downscaling by coherent averaging

      Flexible A-scan rate MHz-OCT: efficient computational downscaling by coherent averaging

      In order to realize adjustable A-scan rates of fast optical coherence tomography (OCT) systems, we investigate averaging of OCT image data acquired with a MHz-OCT system based on a Fourier Domain Mode Locked (FDML) laser. Increased system sensitivity and image quality can be achieved with the same system at the cost of lower imaging speed. Effectively, the A-scan rate can be reduced in software by a freely selectable factor. We demonstrate a detailed technical layout of the strategies necessary to achieve efficient coherent averaging. Since there are many new challenges specific to coherent averaging in swept source MHz-OCT, we analyze ...

      Read Full Article
    19. Linear-in-wavenumber actively-mode-locked wavelength-swept laser

      Linear-in-wavenumber actively-mode-locked wavelength-swept laser

      We report on an akinetic actively-mode-locked wavelength-swept laser (ASL) with a sweep that is highly linear in wavenumber. By tailoring the drive waveform of the intracavity modulator, the wavenumber sweep was further linearized to enable high fidelity frequency-domain interferometric ranging without resampling of the acquired data. Used for catheter-based optical coherence tomography, the ASL showed comparable imaging performance to a state-of-the-art polygon-based wavelength-swept source at a matching sweep rate of 103.6 kHz, a duty cycle of 95%, and a bandwidth of 100 nm, centered at 1330 nm.

      Read Full Article
    20. Frequency-doubled FDML-MOPA laser in the visible

      Frequency-doubled FDML-MOPA laser in the visible

      Wavelength-swept lasers enable high-speed measurements in absorption spectroscopy, Raman spectroscopy, nonlinear Raman hyperspectral microscopy, rapid confocal microscopy, short impulse generation, and most importantly for high-speed optical coherence tomography, with speeds up to video-rate volumetric imaging. Recently, we introduced a pulsed wavelength-swept laser based on the Fourier domain mode-locked (FDML) laser principle combined with a master-oscillator power amplifier (MOPA) architecture. The high peak powers reached with this laser enabled rapid two-photon microscopy and two-photon fluorescence lifetime microscopy and high-speed light detection and ranging measurements. Here, we present the extension of this laser into the visible wavelength range by frequency doubling the ...

      Read Full Article
    21. Stepped frequency comb generation based on electro-optic phase-code mode-locking for moderate-speed circular-ranging OCT

      Stepped frequency comb generation based on electro-optic phase-code mode-locking for moderate-speed circular-ranging OCT

      Circular-ranging (CR) optical coherence tomography (OCT) uses frequency comb sources to improve long-range imaging. While the initial development of CR-OCT focused on extremely high-speed imaging (i.e., operation at A-line rates of several to tens of MHz), there are many applications and imaging strategies for which more moderate speeds are preferred. However, we lack suitable frequency comb sources to enable moderate speed CR-OCT imaging. Here, we describe a novel phase-code mode-locking (PCML) laser architecture that can be operated from the kilohertz to megahertz range, while also offering novel features such as dynamic re-configurability and simplified linear-in-time frequency stepping. We demonstrate ...

      Read Full Article
    22. 9.4 MHz A-line rate optical coherence tomography at 1300 nm using a wavelength-swept laser based on stretched-pulse active mode-locking

      9.4 MHz A-line rate optical coherence tomography at 1300 nm using a wavelength-swept laser based on stretched-pulse active mode-locking

      In optical coherence tomography (OCT), high-speed systems based at 1300 nm are among the most broadly used. Here, we present 9.4 MHz A-line rate OCT system at 1300 nm. A wavelength-swept laser based on stretched-pulse active mode locking (SPML) provides a continuous and linear-in-wavenumber sweep from 1240 nm to 1340 nm, and the OCT system using this light source provides a sensitivity of 98 dB and a single-sided 6-dB roll-off depth of 2.5 mm. We present new capabilities of the 9.4 MHz SPML-OCT system in three microscopy applications. First, we demonstrate high quality OCTA imaging at a ...

      Read Full Article
    23. PhD position on tunable lasers for optical coherence tomography at the University of Kent

      PhD position on tunable lasers for optical coherence tomography at the University of Kent

      We are recruiting for a PhD Studentship in the fields of Optics and Laser Physics, with emphasis on optical coherence tomography for a period of 36 months starting up to 31 January 2021, within the Applied Optics Group, School of Physical Sciences. This is supported by the Marie Curie Innovative Training Network scheme, 860807, EU funded, jointly organised with 14 other universities, companies and hospitals in Europe. You will spend time at the University of Kent and at the other beneficiaries or associated partners. Supervision will be provided in an European setting where specialized and complementary training will be provided ...

      Read Full Article
    1-24 of 429 1 2 3 4 ... 16 17 18 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Popular Articles

  3. Organizations in the News

    1. (1 articles) Massachusetts General Hospital
    2. (1 articles) Harvard University
  4. OCT Companies in the News

    1. (1 articles) Santec
    2. (1 articles) Wasatch Photonics
    3. (1 articles) UTC Aerospace Systems