# Olga KorotkovaUniversity of Miami | UM · Department of Physics

Olga Korotkova

Doctor of Philosophy in Mathematics

## About

316

Publications

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## Publications

Publications (316)

In addition to molecular absorption and scattering from organic and non-organic matter, light waves propagating through oceanic waters may be affected by optical turbulence, i.e., relatively mild and fast variations in the refractive index. The oceanic optical turbulence is primarily caused by fluctuations in temperature and salinity concentration...

Over the last century classical optical coherence has developed from a few vaguely related concepts into a standing along branch of optics, and, more broadly, electromagnetics, that resulted in a number of groundbreaking discoveries concerning nature of light, its evolution and interaction with matter. While the theoretical
developments of this fi...

Theoretical models and results of experimental campaigns relating to non-classic regimes occurring in atmospheric optical turbulence are overviewed. Non-classic turbulence may manifest itself through such phenomena as a varying power law of the refractive-index power spectrum, anisotropy, the presence of constant-temperature gradients and coherent...

The degree of coherence (DOC) function that characterizes the second-order correlations at any two points in a light field is shown to provide a new degree of freedom for carrying information. As a rule, the DOC varies along the beam propagation path, preventing from the efficient information recovery. In this paper, we report that when a partially...

The on-axis cross-spectral density (CSD) of a beam radiated by a stationary source with a circular coherence state and a Gaussian spectral density is obtained in the closed form. It is revealed that the on axis CSD is expressed via the Laplace transform of the source’s degree of coherence or the Hilbert transform of the corresponding pseudo-mode we...

A class of partially coherent spherical sources is introduced whose cross-spectral density across the surface has a modal expansion made up of spherical harmonics. For such sources the solution of the propagation problem in all the outer space can be written through the series of the propagated modes, which maintain the spherical harmonic structure...

Partially coherent scalar sources with cylindrical symmetry radiating outwards are introduced. Homogeneous cross-spectral densities are shown to possess angularly modulated Hankel modes, whose amplitudes are subject to a filtering process during propagation. Simple criteria for treating such sources are given. For the case of an incoherent cylinder...

The recently introduced Coherence-Orbital Angular Momentum (COAM) matrix of a partially coherent beam [Phys. Rev. A 103, 023529 (2021)] is experimentally measured for the first time. The new methodology based on the Young’s interference experiment with a pair of ring-shaped slits with embedded spiral phases is thoroughly described. By introducing t...

We investigate the implications of the singular-value decomposition of the cross-spectral density (CSD) matrix to the description of electromagnetic spectral spatial coherence of stationary light beams. We show that in a transverse plane any CSD matrix can be expressed as a mixture of two CSD matrices corresponding to beams which are fully polarize...

This paper generalizes a pulse-quality metric referred to as P 2 , i.e., the time analogue of Siegman’s beam quality factor M 2 , to include pulsed (nonstationary) random fields of any state of coherence. The analysis begins with the derivation of a general P 2 relation, which we then specialize to the important cases of coherent and Schell-model p...

On-axis spectral density and degree of polarization of beams radiated by electromagnetic (EM) sources with circular correlations are shown to be finely controlled by changing the source parameters. We reveal, in particular, that in this beam class, unlike for all previously known stationary beams, it is possible to control independently the dynamic...

Coherence – Orbital Angular Momentum (COAM) matrix
characterizes the second-order field correlations in stationary
sources or fields, at a pair of spiral modes with the same or
different topological charges, say l and m, and at a pair of radial
positions. In this Letter we reveal the general properties of the
COAM matrix for the broad class of the...

A novel method to achieve the coherence control of spatiotemporal coherency vortices of spatially and temporally partially coherent pulsed vortex (STPCPV) beams is proposed. The influence of spatial and temporal coherence of the source on the phase distributions and the positions of spatiotemporal coherency vortices of the STPCPV beams propagating...

Beer-Lambert-Bouguer law characterizes attenuation of an optical plane wave resolved in terms of absorption and scattering of a medium it passes through. However, optical turbulence present in a medium may also cause severe attenuation in beam-like light fields. This study aims to incorporate the effects of absorption and scattering with that of op...

The degree of coherence and the intensity distribution on the axis of the beam radiated by a planar partially coherent source of the Schell-model type are investigated. We present an expression for the on-axis cross spectral density which is valid for a very general Schell-model source, with the only constraint that the intensity distribution acros...

JOSA A Editor-in-Chief, Olga Korotkova, Feature Editor, Johannes Courtial, and members of the 2021 Emerging Researcher Best Paper Prize Committee announce the recipient of the 2021 prize for the best paper published by an emerging researcher in the Journal.

A Poincaré sphere representation of electromagnetic spectral two-point spatial coherence was recently introduced for fully polarized light beams. In this work, we employ the singular-value decomposition of the cross-spectral density matrix and establish a rigorous interpretation for the formalism in the context of partial polarization. At a single...

A new quantity is introduced for characterization of the on-axis attenuation of a finite laser beam caused by a turbulent medium. It then can be incorporated into the Beer's law accounting for the extended medium's absorption and scattering, and hence provides a simple tool for comparison among the effects of turbulence, absorption and scattering o...

The state of spatial coherence of a partially coherent optical source plays the crucial part in free-space evolution of the major properties of the radiated beam, such as its diffraction rate, spectral composition, intensity distribution and polarization/Orbital Angular Momentum (OAM) states. In particular, various effects of source coherence on th...

Both the intensity distribution and the degree of coherence between pairs of points along the propagation axis (z-coherence) are derived in closed form for a phenomenon of self-focusing produced by circularly coherent light. The first confirms results previously obtained numerically, while the second exhibits new complex features. The physical inte...

We derive two pseudo-modal expansions that provide insight into the structure of stationary electromagnetic sources and can be used for their physical realization and in computer simulations. Both expansions are derived from the vectorial version of Bochner’s theorem of functional analysis. The first expansion employs the incoherent superposition o...

Generalizing our prior work on scalar multi-Gaussian (MG) distributed optical fields, we introduce the two-dimensional instantaneous electric-field vector whose components are jointly MG distributed. We then derive the single-point Stokes parameter probability density functions (PDFs) of MG-distributed light having an arbitrary degree and state of...

A matrix description of orbital angular momentum (OAM) transformations in scalar optical beams by non-local, linear systems is introduced and the amplitude transfer function (ATF) is generalized to include information about mode-to-mode OAM coupling. In particular, the analysis of radially independent systems suggests the existence of unexplored ty...

Statistical optics, and optical coherence in particular, developed into a stand-alone branch of physical optics in the second half of the 20th century and has found a number of ground-breaking applications in astronomical measurements, medical diagnostics, environmental remote sensing, and wireless communications [...]

We propose using ElectroMagnetic Phase Coherence Gratings (EMPCG) for fine spatial segregation in polarimetric components of stationary beams on their propagation in atmospheric turbulence. Unlike for other beams, e.g., non-uniformly correlated EM beams, the off-axis shifts occurring in polarimetric components of the EMPCGs are shown to be invarian...

Classic imaging systems may experience deleterious effects of optical turbulence leading to their quality degradation induced by image jitter and blur. Using a recently introduced model for the refractive index power spectrum of the natural water turbulence accounting for average temperature in the range [0°C, 30°C] and average salinity concentrati...

This monograph overviews classic and recent
developments in theoretical statistical optics in
connection with stationary and non-stationary
(pulsed) optical source characterization and modeling, and
discusses various phenomena occurring with random light
propagating in free space, on its interaction with optical
systems, extended media and particul...

Representation of the cross-spectral density (CSD) function of an optical source or
beam as the incoherent superposition of mutually uncorrelated modes are widely used in imaging
systems and in free space optical communication systems for simplification of the analysis and
reduction of the time-consuming integral calculations. In this paper, we exa...

A broad class of planar, electromagnetic, stationary optical sources obeying the PT symmetry conditions is introduced. On deriving a set of Fourier reciprocity relations obeyed by such sources and far fields they radiate we discover that the latter can only have linear polarization states.

A generalization of the classic Gaussian random variable to the family of multi-Gaussian (MG) random variables characterized by shape parameter $M>0$, in addition to the mean and the standard deviation, is introduced. The probability density function (PDF) of the MG family members is an alternating series of Gaussian functions with suitably chosen...

We present a stable and flexible way to generate the vector
nonuniformly correlated (NUC) beams with a compact optical
system that involves only a single digital mirror device
and a common-path interferometer. The system provides
near real-time generation and accurate control of the phase
difference between the orthogonal field components of
the ve...

We introduce a matrix-based approach for characterization
of local interactions of optical beams with devices that result
in changes of their orbital angular momentum (OAM) content.
For deterministic interactions, a method similar to the
Jones calculus is developed, while for interactions involving
random beams and/or devices, its generalization ba...

The expressions for the wave and the phase structure functions of a plane wave and a spherical wave propagating in the natural water turbulence characterized by the recently developed spatial power spectrum (Yao et al., 2020) are evaluated in general and in the limits of large and small separations. The spatial coherence radius for both plane and s...

The evolution of the 4 × 4 matrix with elements being the scintillation indices of the single-point Stokes parameters of a stationary electromagnetic beam-like optical field in classic, weak atmospheric turbulence is revealed. It is shown that depending on the choice of the source parameters, the source-induced changes in the matrix elements of the...

A class of wide-stationary optical sources with a specially designed degree of coherence profile is introduced for radiating spectral densities with a vortex whose core’s location and size can be controlled at a specified range. This is achieved by modeling of the source coherence state as a combination of a helicoidal separable phase and a Cartesi...

We introduce a Poincaré sphere construction for geometrical
representation of the state of two-point spatial coherence
in random electromagnetic (vectorial) beams. To this end, a
novel descriptor of coherence is invoked, which shares some
important mathematical properties with the polarization
matrix and spans a new type of Stokes parameter space....

We propose a method for structuring the spatial coherence state of light via mixed linear combinations of N complex degrees of coherence (CDC) and specify the conditions under which such combinations represent a valid CDC. Several examples demonstrate that this method opens previously unknown avenues for modeling random sources, radiating to light...

A new family of partially coherent pulsed beams with spatial cosine-Gaussian and temporal Laguerre–Gaussian correlations, named spatial cosine-Gaussian and temporal Laguerre–Gaussian correlated Schell-model (SCTLGSM) pulsed beams, is introduced. An analytic propagation formula is derived for the SCTLGSM pulsed beam through the spatiotemporal ABCD o...

The effect of natural turbulence on an underwater wireless optical communication (UWOC) link using the on-off-key (OOK) modulation scheme and a coherent plane wave is analyzed in terms of the signal-to-noise ratio (SNR) and the bit-error-rate (BER). The optical turbulence is considered to be isotropic and homogeneous, which is typically the case al...

The recently introduced power spectrum of the refractive index fluctuations of the natural oceanic water turbulence is applied to an underwater communication system in the presence of adaptive optics corrections. The effects of the average temperature [0-30degC], the average salinity [0-40ppt], the temperature-salinity gradient ratio [0-400degC/ppt...

A matrix representation is introduced for stationary beamlike light fields that allows for simultaneous treatment of the orbital angular momentum (OAM) and the second-order state of spatial coherence. This coherence-OAM matrix is a counterpart of the 2×2 beam coherence-polarization matrix in a Cartesian polarization basis or coherence-spin angular...

We suggest tailoring of the illumination's complex degree of coherence for imaging specific two-and three-point objects with resolution far exceeding the Rayleigh limit. We first derive a formula for the image intensity via the pseudo-mode decomposition and the fast Fourier transform valid for any partially coherent illumination (Schell-like, non-u...

A potential scattering theory from parity-time (PT) collections of particles with gain and loss is introduced, and the forms of their structure and pair-structure factors are elucidated. An example relating to light scattering from a random distribution of a pair of particles with gain and loss is considered.

Up to now, methods for generating non-uniformly correlated light have been of two kinds: one is based on the use of specially designed random phase screens, and the other relies on the coherent-mode superposition, both being very complex experimental procedures. In this Letter, we show both theoretically and experimentally that in Young's interfere...

Light propagation in turbulent media is conventionally studied with the help of the spatio-temporal power spectra of the refractive index fluctuations. In particular, for natural water turbulence several models for the spatial power spectra have been developed based on the classic, Kolmogorov postulates. However, as currently widely accepted, non-K...

The effect of natural turbulence on an underwater wireless optical communication (UWOC) link using the on-off-key (OOK) modulation scheme and a coherent plane wave is analyzed in terms of the signal-to-noise ratio (SNR) and the bit-error-rate (BER). The optical turbulence is considered to be isotropic and homogeneous, which is typically the case al...

A theoretical framework is developed for scattering of scalar radiation from stationary, three-dimensional media with correlation functions of scattering potentials obeying PT symmetry. It is illustrated that, unlike in scattering from deterministic PT-symmetric media, its stationary generalization involves two mechanisms leading to symmetry breaki...

We discuss the properties of the COAM (coherence-orbital angular momentum) formalism for describing the OAM properties of partially coherent beams, and possible uses in applications.

A potential scattering theory from deterministic and random PT collections of particles with gain and loss is introduced and the forms of their structure and pair-structure factors are elucidated. An example relating to light scattering from a random distribution of a pair of particles with gain and loss is considered.

A matrix representation is introduced for stationary beam-like light fields that allows for simultaneous treatment of the orbital angular momentum (OAM) and the second-order state of spatial coherence. This Coherence-OAM matrix is a counterpart of the 2 x 2 beam Coherence-polarization matrix in a Cartesian polarization basis or Coherence-spin angul...

We demonstrate that the orbital angular momentum (OAM) flux density of a paraxial light beam can change on propagation in free space. These changes are entirely due to the spatial coherence state of the source, and the effect is analogous to correlation-induced changes in the intensity, spectrum, and polarization of a beam. The use of the source co...

A theoretical framework is developed for scattering of scalar radiation from stationary, three-dimensional media with correlation functions of scattering potentials obeying PT-symmetry. It is illustrated that unlike in scattering from deterministic PT-symmetric media, its stationary generalization involves two mechanisms leading to symmetry breakin...

Light propagation in turbulent media is conventionally studied with the help of the spatio-temporal power spectra of the refractive index fluctuations. In particular, for natural water turbulence several models for the spatial power spectra have been developed based on the classic, Kolmogorov postulates. However, as currently widely accepted, non-K...

The applicability limits of the small complex phase perturbation (Rytov) theory for laser light propagation in soft biological tissues have been tackled. We have found that for typical coherent optical waves and for several types of optically soft biological tissues with known spatial power spectra, the weak regime of light-field fluctuations is li...

We introduce an optical system for the nearly real-time generation of a wide class of partially coherent sources (PCSs) having non-Schell model circular coherence. The system is composed of a modified 4f optical imaging system involving a fast modulated digital micro-mirror
device (DMD) and a stable common path interferometric arrangement, which en...

The power spectrum of water optical turbulence is shown to vary with its average temperature and average salinity concentration , as well as with light wavelength λ. This study explores such variationsfor ∈ [0◦C, 30 ◦C], ∈ [0 ppt, 40 ppt] covering most of the possible natural water conditions within the Earth’s boundary layer and for visible electr...

It is shown that fine phase structuring of the temporal degree of coherence of a non-stationary pulse source leads to breaking its average arrival time symmetry on propagation in a linear dispersive medium. We employ the temporal counterpart of a recently proposed sliding function technique [Opt. Lett. 43, 4727 (2018)] for obtaining several models...

The well-established model for the spatial correlation function of the refractive index fluctuations in a statistically stationary biological tissue [Sheppard CJR. Fractal model of light scattering in biological tissue and cells. Opt Lett. 2007;32:142–144] is applied to the direct scattering problem of light within the validity regimes of the first...

We investigate, via both experimental measurements and wave-optics computer simulations, the statistical characteristics of the fluctuating intensity, such as the average intensity, the beam wander and the scintillation index, of the Gaussian Schell-model (GSM) beams on
passing through double-pass, monostatic turbulence channels with either a retro...

The power spectrum of water optical turbulence is shown to vary with its average temperature ⟨T⟩ and average salinity concentration ⟨S⟩, as well as with light wavelength λ. This study explores such variations for ⟨T⟩∈[0 deg,30 deg], ⟨S⟩∈[0 ppt,40 ppt] covering most of the possible natural water conditions within the Earth's boundary layer and for v...

A recent theoretical prediction on the existence of the Enhanced BackScatter (EBS) effect in oceanic turbulence is confirmed experimentally. A comparison is also made between the laser beam EBS occurring in air and water turbulence.

We introduce a class of planar, stationary sources whose cross-spectral densities carry a combination of helical and Cartesian phases. The helical phase is linear, separable in polar coordinates, resulting in a vortex-like average intensity with a dark area centered on the optical axis; the Cartesian counterpart is separable in the x- and y-coordin...

We demonstrate that the orbital angular momentum flux density of a paraxial light beam can change on propagation in free space. These changes are entirely due to the spatial coherence state of the source, and the effect is analogous to correlation-induced changes in the intensity, spectrum and polarization of a beam. The use of the source coherence...

A stationary beam forming an Airy-like spectral density in the far field is analyzed theoretically and experimentally. The Schell-model source that radiates such a beam is an extended version of a recently introduced source [O. Korotkova, et al., Opt. Lett. 43, 4727 (2018); X. Chen, et al., Opt. Lett. 44, 2470 (2019), in 1D and 2D, respectively]. W...

In this paper, the propagation of Temporal Coherence Grating (TCG) pulse trains in a dispersive medium with a chirp is investigated for the first time. The two-time mutual coherence function of the TCG pulse trains propagating through extended dispersive medium specified by temporal ABCD matrix is derived and the evolution of their mean intensity a...

We introduce a class of partially coherent, Schell-type sources whose degree of coherence is represented by a finite series of complex-valued functions. The significance of implementing such a series is due to the fact that one can manipulate the weighting coefficients of
the series with terms having a computationally trivial linear phase of the de...

Theoretical predictions of light beam interactions with jet engine exhaust are of importance for optimization of various optical systems, including LIDARs, imagers and communication links operating in the vicinity of aircrafts and marine vessels. Here we extend the analysis previously carried out for coherent laser beams propagating in jet engine e...

Optical turbulence occurring in the oceanic waters may be detrimental for light beams used in the short-link communication and sensing systems, and, in particular, in underwater LIDARs. We develop a theory capable of predicting the passage of light beams through the bi-static LIDAR systems, for a wide variety of optical waves, including partially c...

It is well known that in free atmosphere the Kolmogorov power spectrum of the refractive index might not properly describe the actual turbulence behavior. In this paper, we use general non-Kolmogorov power spectrum for theoretical investigation of laser beam propagation in the double-passage problem: transmitter–target–receiver. The major applicati...

The spatially resolved Mueller matrix of a mono-static optical system with the corner-cube retro-reflector operating in the presence of clear-air atmospheric turbulence is measured for the first time, to the best of our knowledge. The changes in the polarization properties of the beam are caused by the combination of deterministic polarimetric modu...

A recently suggested technique for modeling of the complex coherence states of scalar stationary light beams [Opt. Lett. 43, 4727 (2018)] is extended to the electromagnetic (EM) domain. It is shown that spatially varying phase profiles of the 2 × 2 source correlation matrix allow for fine, independent , two-dimensional spatial control of the three...

Light influenced by the turbulent ocean can be fully characterized with the help of the power spectrum of the water's refractive index fluctuations, resulting from the combined effect of two scalars, temperature and salinity concentration advected by the velocity field. The Nikishovs' model [Fluid Mech. Res. 27, 8298 (2000)] frequently used in the...

We show experimentally that the polarization properties of the return wave in a monostatic double-pass optical system with a glass corner-cube retroreflector operating in the clear-air turbulent atmosphere are modulated in a complex manner. This effect is due to deterministic modulation of the direct beam’s polarization state by the three cube’s fa...

The scintillation index of the I0-Bessel-correlated beams generated as temporally incoherent superposition of Laguerre-Gaussian modes with different coherence states and different values of the Orbital Angular Momentum (OAM) index on propagation in atmospheric turbulence is reported. The scintillation index is shown to decrease with the increase in...

It was shown in a recent publication [Opt. Lett. 43,4727 (2018)] that structuring of the phase of the 1D source complex coherence states results in breaking of the Cartesian symmetry for the far-field spectral density leading to its one-sided radial acceleration, asymmetric splitting and other effects. We extend this result from 1D to 2D (scalar) o...

Light interaction with the turbulent ocean can be fully characterized with the help of the power spectrum of the water's refractive index fluctuations, resulting from the combined effect of two scalars, temperature and salinity concentration advected by the velocity field. The Nikishovs' model [Fluid Mech. Res. 27, 8298 (2000)] frequently used in t...

The effects of non-trivial phase of the source degree of coherence on the far-field spectral density for the class of one-dimensional, Multi-Gaussian Schell-model beams are explored. While in the absence of the phase the flat-top spectral density profile with a Gaussian edge drop is symmetrically formed in the far field about the optical axis, vari...

Method based on autoconvolution of Hermitian function is introduced for phase structuring of Schell-like complex coherence states. Coherence curve concept is introduced. Phase manipulation of model scalar and electromagnetic coherence states is discussed.

Several planar curves that are well known from mechanics, astronomy, acoustics, etc., and used in other branches of optics, such as caustics and light robotics, are employed for modeling of the recently introduced coherence curves [Opt. Lett.43, 4727 (2018)OPLEDP0146-959210.1364/OL.43.004727]. These planar curves have intrinsic relationships betwee...