The Experts below are selected from a list of 78 Experts worldwide ranked by ideXlab platform

Andrey A. Chabanov - One of the best experts on this subject based on the ideXlab platform.

  • Intensity statistics of random signals in Gaussian noise.
    Physical Review E, 2009
    Co-Authors: Andrey A. Chabanov
    Abstract:

    The intensity statistics of random signals in the presence of Gaussian noise is obtained by considering the model of a random signal plus a random Phasor Sum. The additive Gaussian noise is shown to result in a Bessel transform of the probability density of signal intensity. The transformation of the intensity statistics can generally be applied to mixtures of independent random signals, one of which being a complex-valued Gaussian random process. It is used to retrieve intensity statistics of microwave pulsed transmission from Gaussian noise at long time delays.

Wei Wang - One of the best experts on this subject based on the ideXlab platform.

  • Statistics of polarization speckle produced by a constant polarization Phasor plus a random polarization Phasor Sum.
    Journal of the Optical Society of America. A Optics image science and vision, 2020
    Co-Authors: Wei Wang, Shun Zhang, Joseph Grimble
    Abstract:

    The statistical properties of the polarization speckle produced by a random polarization Phasor Sum plus a constant polarization Phasor are studied. Based on the Gaussian asSumption for the random electric field, the three-dimensional joint probability density functions of the Stokes parameters and the parameters characterizing the polarization ellipse for the produced random polarization fields are obtained. Subsequently, the statistics of an isotropic polarization speckle with a coherent polarization background have been investigated. The joint and marginal probability densities of these random variables are given to study the effect of the constant polarization background on the statistics of random polarization fields.

  • Development of polarization speckle based on random polarization Phasor Sum.
    Journal of the Optical Society of America. A Optics image science and vision, 2019
    Co-Authors: Chunmei Zhang, Sean Horder, Tim K. Lee, Wei Wang
    Abstract:

    The random-walk approach has been extended and applied to study the development of polarization speckle by taking the vector nature into account for stochastic electric fields. Based on the random polarization Phasor Sum, the first and second moments of the Stokes parameters of the resultant polarization speckle have been examined. Under certain asSumptions about the statistics of the component polarization Phasors that make up the Sum, we present some of the details of the spatial derivation that lead to the expressions for the degree of polarization and the newly proposed Stokes contrast that are suitable for describing the polarization speckle development. This vectorial extension of the random walk will provide an intuitive explanation for the development of the polarization speckle.

  • Generation and development of polarization speckle based on random walks of polarization Phasor
    Third International Conference on Photonics and Optical Engineering, 2019
    Co-Authors: Wei Wang, Tim K. Lee, Steen Grüner Hanson, Mitsuo Takeda
    Abstract:

    In this paper, we review our recent work on the statistical properties of polarization speckle with its unique properties of random polarization states fluctuating in space. From random walks of polarization Phasor, we provide the origins of the polarization speckle by taking the vector nature into account for stochastic electric fields. Based on the random polarization Phasor Sum as an extension of conventional random Phasor Sum, the first and second moments of the Stokes parameters of the resultant polarization speckle have been examined. Two types of devices for polarization optics, i.e. rough-surfaced retardation plate and random polarizer array, will be introduced as the physical realization of the desired phenomena of polarization speckles. Some statistical properties of the stochastic electric fields are reviewed in order to understand the performance of these two polarization optics devices for generation and development of the polarization speckle.

Brett E. Bouma - One of the best experts on this subject based on the ideXlab platform.

  • Estimation of the scattering coefficients of turbid media using angle-resolved optical frequency-domain imaging
    Optics letters, 2007
    Co-Authors: Adrien E. Desjardins, Benjamin J. Vakoc, A. Bilenca, Guillermo J. Tearney, Brett E. Bouma
    Abstract:

    Noninvasive measurements of the scattering coefficients of optically turbid media using angle-resolved optical frequency-domain imaging (OFDI) are demonstrated. It is shown that, by incoherently averaging OFDI reflectance signals acquired at different backscattering angles, speckle noise is reduced, allowing scattering coefficients to be extracted from a single A-line with much higher accuracy than with measurements from conventional OFDI and optical coherence tomography systems. Modeling speckle as a random Phasor Sum, the relationship between the measurement accuracy and the number of compounded angles is derived. The sensitivity analysis is validated with measurements from a tissue phantom.

Tim K. Lee - One of the best experts on this subject based on the ideXlab platform.

  • Development of polarization speckle based on random polarization Phasor Sum.
    Journal of the Optical Society of America. A Optics image science and vision, 2019
    Co-Authors: Chunmei Zhang, Sean Horder, Tim K. Lee, Wei Wang
    Abstract:

    The random-walk approach has been extended and applied to study the development of polarization speckle by taking the vector nature into account for stochastic electric fields. Based on the random polarization Phasor Sum, the first and second moments of the Stokes parameters of the resultant polarization speckle have been examined. Under certain asSumptions about the statistics of the component polarization Phasors that make up the Sum, we present some of the details of the spatial derivation that lead to the expressions for the degree of polarization and the newly proposed Stokes contrast that are suitable for describing the polarization speckle development. This vectorial extension of the random walk will provide an intuitive explanation for the development of the polarization speckle.

  • Generation and development of polarization speckle based on random walks of polarization Phasor
    Third International Conference on Photonics and Optical Engineering, 2019
    Co-Authors: Wei Wang, Tim K. Lee, Steen Grüner Hanson, Mitsuo Takeda
    Abstract:

    In this paper, we review our recent work on the statistical properties of polarization speckle with its unique properties of random polarization states fluctuating in space. From random walks of polarization Phasor, we provide the origins of the polarization speckle by taking the vector nature into account for stochastic electric fields. Based on the random polarization Phasor Sum as an extension of conventional random Phasor Sum, the first and second moments of the Stokes parameters of the resultant polarization speckle have been examined. Two types of devices for polarization optics, i.e. rough-surfaced retardation plate and random polarizer array, will be introduced as the physical realization of the desired phenomena of polarization speckles. Some statistical properties of the stochastic electric fields are reviewed in order to understand the performance of these two polarization optics devices for generation and development of the polarization speckle.

David D Sampson - One of the best experts on this subject based on the ideXlab platform.

  • correlation of static speckle with sample properties in optical coherence tomography
    Optics Letters, 2006
    Co-Authors: Timothy R Hillman, Steven G Adie, Volker Seemann, Julian J Armstrong, Steven L Jacques, David D Sampson
    Abstract:

    We present theoretical calculations, based on a random Phasor Sum model, which show that the optical coherence tomography speckle contrast ratio is dependent on the local density of scattering particles in a sample, provided that the effective number of scatterers in the probed volume is less than about five. We confirm these theoretical predictions experimentally, using suspensions of microspheres in water. The observed contrast ratios vary in value from the Rayleigh limit of 0.52 to in excess of 2, suggesting that the contrast ratio could be useful in optical coherence tomography, particularly when imaging in ultrahigh-resolution regimes.