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    1. Mentioned In 175 Articles

    2. Bonded tunable VCSEL with bi-directional actuation

      Bonded tunable VCSEL with bi-directional actuation
      A MEMS tunable VCSEL includes a membrane device having a mirror and a distal-side electrostatic cavity for displacing the mirror to increase a size of an optical cavity. A VCSEL device includes an active region for amplifying light. Then, a proximal-side electrostatic cavity is defined between the VCSEL device and the membrane device is used to displace the mirror to decrease a size of an optical cavity.
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    3. Linewidth considerations for MEMS tunable VCSEL LiDAR

      Linewidth considerations for MEMS tunable VCSEL LiDAR
      The flexible membranes used in MEMS tunable VCSELs are so small and light that thermally induced vibrations can impact laser performance. We measure the thermal vibration spectrum of such a membrane showing peaks at the spatial vibration mode resonant frequencies of the membrane/plate. These vibrations result in a theoretical floor to the linewidth of the VCSEL. Frequency domain LiDAR and optical coherence tomography systems can get around this thermal ...
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    4. Changes in entropy on polarized-sensitive optical coherence tomography images after therapeutic subthreshold micropulse laser for diabetic macular edema: A pilot study

      Changes in entropy on polarized-sensitive optical coherence tomography images after therapeutic subthreshold micropulse laser for diabetic macular edema: A pilot study
      ...28 ]. In brief, the light source used in an optical interferometer of the PS-OCT was a frequency-swept laser (Axsun Technologies, Billerica, MA, USA); its central wavelength, sweep repetition frequency, and wavelength ra...
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    5. Advantage of low NEP balanced receivers in swept source OCT

      Advantage of low NEP balanced receivers in swept source OCT
      Low NEP balanced receivers generally do not result in better sensitivity in a shot-noise-limited swept source OCT system. However, there is an advantage if RIN is significant. A lower NEP, even in the shot-noise-limited case, does allow for lower reference arm powers. This, in turn, reduces fixed pattern artifact signals caused by stray optical component reflections inside a swept source laser cavity. An NEP reduction of 10 allows the reference ...
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    6. OCT applications in optics R&D and manufacturing

      OCT applications in optics R&D and manufacturing
      Optical coherence tomography (OCT) can be an important diagnostic tool in optics RD and manufacturing. We illustrate this with four applications. (1) Imaging of vibration modes of MEMS membranes. (2) Strain mapping of VCSEL chips. (3) Optical frequency domain reflectometry (OFDR) of laser cavities. (4) Combined responsivity and 3D mapping of photodiode packages.
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    7. 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 ...
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    8. 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.
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    9. Achieving the ideal point spread in swept source OCT

      Achieving the ideal point spread in swept source OCT
      Side lobe artifacts on point spread functions can be traced back to (1) fringe visibility variation across the spectrum, (2) errors in sampling instances, and (3) window functions. We demonstrate signal processing methods for correcting for all three of these issues. These methods require a system calibration step. If the systems slowly age, the recalibration step could be performed in the field with a fixtured target.
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    10. Optical coherence tomography (OCT) system having integrated detector and analysis systems

      Optical coherence tomography (OCT) system having integrated detector and analysis systems
      An optical detector system comprises a hermetic optoelectronic package, an optical bench installed within the optoelectronic package, a balanced detector system installed on the optical bench. The balanced detector system includes at least two optical detectors that receive interference signals. An electronic amplifier system installed within the optoelectronic package amplifies an output of at least two optical detectors. Also disclosed is an integrated optical coherence tomography system. Embodiments are provided ...
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    11. Real time FPGA resampling for swept source optical coherence tomography

      Real time FPGA resampling for swept source optical coherence tomography
      Real-time swept source OCT data is most often sampled using a specially cut hardware k-clock. The present invention involves mathematically resampling signals within an FPGA-based data acquisition board based on data sampled from a wide free spectral range reference interferometer. The FPGA can then multiply up the reference clock rate to achieve greater imaging depth. The Nyquist fold-over depth can thus be programmed from a standard reference to an arbitrary ...
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    12. Laser swept source with controlled mode locking for OCT medical imaging

      Laser swept source with controlled mode locking for OCT medical imaging
      An optical coherence analysis system uses a laser swept source that is constrained to operate in a mode locked condition. This is accomplished by synchronously changing the laser cavity's gain and/or phase based on the round trip travel time of light in the cavity. Many high-speed wavelength swept laser sources emit pulses synchronized with the round trip time of the cavity as part of a nonlinear optical frequency ...
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    13. Temperature stabilized phase reference for MEMS based swept sources

      Temperature stabilized phase reference for MEMS based swept sources
      MEMS tunable lasers are not inherently phase stable because Brownian motion and drive electronics noise make the starting wavelength of the sweep unstable with respect to the electrical sweep trigger. A typical solution to the problem is to use a fiber Bragg reflector wavelength trigger. That is a sub-optimal solution since environmental changes can move both the Bragg peak and the k-clock phase. We have packaged temperature controlled trigger and ...
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    14. Tunable 1060nm VCSEL co-packaged with pump and SOA for OCT and LiDAR

      Tunable 1060nm VCSEL co-packaged with pump and SOA for OCT and LiDAR
      A 1060 nm optically pumped tunable VCSEL was formed from an InGaAs/AlGaAs/GaAs half-VCSEL bonded to a MEMS movable mirror on a silicon substrate. The VCSEL was co-packaged in a 14-pin butterfly module with an 825 nm pump laser and a 1060 nm semiconductor optical amplifier. The co-packaged device exhibited shot-noise-limited sensitivity with up to 50 mW output power and 75 nm tunability. Ophthalmic OCT, especially whole-eye imaging and ...
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    15. 1-15 of 175 1 2 3 4 ... 10 11 12 »
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  2. About Excelitas Technologies

    Excelitas Technologies

    Excelitas Technologies is a technology leader in delivering high-performance, market-driven photonic innovations to meet the lighting, optronic, detection and optical technology needs of customers worldwide. Serving a vast array of applications across automotive, consumer products, defense and aerospace, industrial, medical, safety and security, and sciences sectors, Excelitas Technologies stands committed to promoting our customers' success.