1. Articles from J. Kalkman

    1-10 of 10
    1. Fourier-Domain Optical Coherence Tomography Signal Analysis and Numerical Modeling

      Fourier-Domain Optical Coherence Tomography Signal Analysis and Numerical Modeling

      In this work the theory of the optical coherence tomography (OCT) signal after sampling, in dispersive media, with noise, and for a turbid medium is presented. The analytical theory is demonstrated with a one-dimensional numerical OCT model for (single) reflectors, dispersive media, and turbid media. For dispersive media the deterioration of the OCT axial resolution is quantified analytically and numerically. The OCT signal to noise ratio (SNR) is analyzed in the Fourier-domain and simulated with the numerical model. For an SNR based on the OCT intensity the conventional shot noise limited SNR is derived whereas for an SNR based on ...

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    2. Transmission optical coherence tomography based measurement of optical material properties

      Transmission optical coherence tomography based measurement of optical material properties

      We present transmission optical coherence tomography (transmission OCT) as a versatile tool to measure optical material properties of turbid media. The transmission OCT signal is described in detail and it is demonstrated how the group refractive index ( n g ), group velocity dispersion (GVD) and optical attenuation can be determined from this signal. We experimentally validate the refractive index properties of glasses, liquids and glucose water solutions in terms of n g and GVD. Measurements of scattering coefficients are determined using transmission OCT for suspensions of silica particles. Quantitative agreement is obtained with a dependent scattering model, both for the average ...

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    3. Dependent and multiple scattering in transmission and backscattering optical coherence tomography

      Dependent and multiple scattering in transmission and backscattering optical coherence tomography

      We use transmission and backscattering optical coherence tomography (OCT) to distinguish and quantify dependent and multiple scattering effects in turbid media. With transmission OCT the dependent scattering coefficients for a range of monodisperse silica particle suspensions are determined. An excellent agreement is observed between the measured dependent scattering coefficients and calculations based on Mie calculations, the Percus-Yevick radial distribution function, and coherent light scattering theory. Backscattering OCT measurements are fitted using the extended Huygens-Fresnel (EHF) model with the dependent scattering coefficients obtained from the transmission OCT measurements as input parameters. Good agreement between the EHF model and the backscattering OCT ...

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    4. Feature Of The Week 1/27/13: An Exciting and Promising Area for OCT System Research and Commercial Opportunities

      Feature Of The Week 1/27/13: An Exciting and Promising Area for OCT System Research and Commercial Opportunities

      One of the most promising areas for OCT system research is the pursuit of photonic integrated circuits (PICs) and optoelectronic integrated circuits (OEICs) for OCT systems. Such approaches offer to dramatically reduce the size, weight, power, and costs of future OCT systems. Such reductions could enable increase adoption of OCT in existing markets and open up a wide range of new applications and markets for OCT. While there remain several difficult challenges ahead there has already been massive R&D investments (~$100M) and major advances in this area in the fiber optic telecommunication industry and those advances are poised ...

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    5. Integrated-optics-based swept-source optical coherence tomography

      Integrated-optics-based swept-source optical coherence tomography

      We designed, fabricated, and characterized an integrated-optics-based swept-source optical coherence tomography (SS-OCT) system in TriPleX technology. An external 1300 nm swept source is coupled to the chip, which contains waveguide structures for interferometric depth ranging and balanced detection. The complete OCT chip has a footprint of 0.4     cm × 1.8     cm . Light from the chip is focused onto the s.ample using an aspheric lens; the lateral resolution is 21 ± 1     μ m . OCT measurements, performed with a moveable mirror, demonstrate a sensitivity of − 80     dB and imaging up to the maximum depth of 5.09 mm. Corrected for dispersion ...

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    6. Multiple scattering effects in Doppler optical coherence tomography of flowing blood

      Multiple scattering effects in Doppler optical coherence tomography of flowing blood

      We investigate the effect of multiple scattering on the optical coherence tomography (OCT) signal and the Doppler OCT signal of flowing blood. Doppler OCT measurements at 1300 nm are performed on flowing diluted porcine blood with hematocrit ranging between 0% and 15%. Measured blood hematocrit and mean red blood cell volume are used to calculate, using the discrete dipole approximation model, the (single) scattering coefficient and scattering anisotropy of blood. Monte Carlo simulations, based on the calculated scattering coefficients and scattering anisotropies, are compared to Doppler OCT measurements for hematocrit smaller than 10%. Good quantitative agreement between Doppler OCT measurements ...

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    7. Determination of the scattering anisotropy with optical coherence tomography

      Determination of the scattering anisotropy with optical coherence tomography
      In this work we demonstrate measurements with optical coherence tomography (OCT) of the scattering phase function in the backward direction and the scattering anisotropy parameter g. Measurements of the OCT attenuation coefficient and the backscattering amplitude are performed on calibrated polystyrene microspheres with a time-domain OCT system. From these measurements the phase function in the backward direction is determined. The measurements are described by the single scattering model and match Mie calculations very well. Measurements on Intralipid demonstrate the ability to determine the g of polydisperse samples and, for Intralipid, g = 0.35 ± 0.03 is measured, which is well ...
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    8. Path-Length-Resolved Diffusive Particle Dynamics in Spectral-Domain Optical Coherence Tomography

      Path-Length-Resolved Diffusive Particle Dynamics in Spectral-Domain Optical Coherence Tomography
      We describe a new method to measure the decorrelation rate of the optical coherence tomography (OCT) magnitude simultaneously in space and time.We measure the decorrelation rate of the OCT magnitude in a Fourier-domain OCT system for a large range of translational diffusion coefficients by varying the sphere diameter. The described method uses the sensitivity advantage of Fourier-domain OCT over time-domain OCT to increase the particle diffusion imaging speed by a factor of 200. By coherent gating, we reduce the contribution of multiple scattering to the detected signal, allowing a quantitative study of diffusive particle dynamics in high concentration samples ...
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    9. Quantitative comparison of the OCT imaging depth at 1300 nm and 1600 nm

      Quantitative comparison of the OCT imaging depth at 1300 nm and 1600 nm
      One of the present challenges in optical coherence tomography (OCT) is the visualization of deeper structural morphology in biological tissues. Owing to a reduced scattering, a larger imaging depth can be achieved by using longer wavelengths. In this work, we analyze the OCT imaging depth at wavelengths around 1300 nm and 1600 nm by comparing the scattering coefficient and OCT imaging depth for a range of Intralipid concentrations at constant water content. We observe an enhanced OCT imaging depth for 1600 nm compared to 1300 nm for Intralipid concentrations larger than 4 vol.%. For higher Intralipid concentrations, the imaging depth ...
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    10. Multiple and dependent scattering effects in Doppler optical coherence tomography

      Multiple and dependent scattering effects in Doppler optical coherence tomography
      Doppler optical coherence tomography (OCT) is a technique to image tissue morphology and to measure flow in turbid media. In its most basic form, it is based on single (Mie) scattering. However, for highly scattering and dense media multiple and concentration dependent scattering can occur. For Intralipid solutions with varying scattering strength, the effect of multiple and dependent scattering on the OCT signal attenuation and Doppler flow is investigated. We observe a non-linear increase in the OCT signal attenuation rate and an increasingly more distorted Doppler OCT flow profile with increasing Intralipid concentration. The Doppler OCT attenuation and flow measurements ...
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    1-10 of 10
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  2. Topics in the News

    1. (10 articles) Jeroen Kalkman
    2. (8 articles) Ton G. van Leeuwen
    3. (6 articles) Academic Medical Center at the University of Amsterdam
    4. (4 articles) Dirk J. Faber
    5. (3 articles) Delft University of Technology
    6. (3 articles) University of Twente
    7. (3 articles) Van Duc Nguyen
    8. (2 articles) University of Oulu
    9. (2 articles) Alexander V. Bykov
    10. (2 articles) Baylor College of Medicine
    11. (2 articles) Irina V. Larina
    12. (1 articles) VU University Amsterdam
    13. (1 articles) Johns Hopkins University
    14. (1 articles) Dalhousie University
    15. (1 articles) Technical University of Munich
    16. (1 articles) University of North Carolina
    17. (1 articles) University of Toronto
    18. (1 articles) Amy L. Oldenburg
    19. (1 articles) Shang Wang
    20. (1 articles) Carl Zeiss Meditec
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    Multiple and dependent scattering effects in Doppler optical coherence tomography Quantitative comparison of the OCT imaging depth at 1300 nm and 1600 nm Path-Length-Resolved Diffusive Particle Dynamics in Spectral-Domain Optical Coherence Tomography Determination of the scattering anisotropy with optical coherence tomography Multiple scattering effects in Doppler optical coherence tomography of flowing blood Integrated-optics-based swept-source optical coherence tomography Feature Of The Week 1/27/13: An Exciting and Promising Area for OCT System Research and Commercial Opportunities Dependent and multiple scattering in transmission and backscattering optical coherence tomography Transmission optical coherence tomography based measurement of optical material properties Fourier-Domain Optical Coherence Tomography Signal Analysis and Numerical Modeling Cooperative low-rank models for removing stripe noise from OCTA images MS-CAM: Multi-Scale Class Activation Maps for Weakly-supervised Segmentation of Geographic Atrophy Lesions in SD-OCT Images