Generation of a high-quality partially coherent dark hollow beam with a multimode fiber
TL;DR: The experimental generation of a high-quality partially coherent dark hollow beam (DHB) is reported by coupling a partially coherent beam into a multimode fiber (MMF) with a suitable incidence angle by closely controlled coherence of the input beam.
Abstract: We report the experimental generation of a high-quality partially coherent dark hollow beam (DHB) by coupling a partially coherent beam into a multimode fiber (MMF) with a suitable incidence angle. The interference experiment of the generated partially coherent DHB passing through double slits is demonstrated. It is found that the coupling efficiency of the MMF, the quality, and the coherence of the generated partially coherent DHB are closely controlled by the coherence of the input beam.
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TL;DR: In this paper, proper-ties, generation methods and emerging applications for non-Gaussian beam shapes are discussed, including Bessel, an-nular, and vortex beams.
Abstract: Non-Gaussian beam profiles such as Bessel or an- nular beams enable novel approaches to modifying materials through laser-based processing. In this review paper, proper- ties, generation methods and emerging applications for non- conventional beam shapes are discussed, including Bessel, an- nular, and vortex beams. These intensity profiles have important implications in a number of technologically relevant areas includ- ing deep-hole drilling, photopolymerization and nanopatterning, and introduce a new dimension for materials optimization and fundamental studies of laser-matter interactions.
534 citations
TL;DR: A review of recent developments on generation and propagation of partially coherent beams with nonconventional correlation functions is presented.
Abstract: Partially coherent beams with nonconventional correlation functions have displayed many extraordinary properties, such as self-focusing and self-splitting, which are totally different from those of partially coherent beams with conventional Gaussian correlated Schell-model functions and are useful in many applications, such as optical trapping, free-space optical communications, and material thermal processing. In this paper, we present a review of recent developments on generation and propagation of partially coherent beams with nonconventional correlation functions.
182 citations
Cites background from "Generation of a high-quality partia..."
..., Gaussian correlated Schell-model functions) have been studied extensively in both theory and experiment [1–16] and have found wide applications, such as in free-space optical communications [17], particle trapping [9,18–20], atom cooling [21], atomic recoil lasing [22], optical imaging [23,24], laser scanning [25], inertial confinement fusion [26], reduction of noise in photography [27], second-harmonic generation [28,29], and optical scattering [30,31]....
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TL;DR: The numerical results show that the M(2)- factor of a DHB in turbulent atmosphere increases on propagation, which is much different from its invariant properties in free-space, and is mainly determined by the parameters of the beam and the atmosphere.
Abstract: Analytical formula is derived for the M2-factor of coherent and partially coherent dark hollow beams (DHB) in turbulent atmosphere based on the extended Huygens-Fresnel integral and the second-order moments of the Wigner distribution function. Our numerical results show that the M2- factor of a DHB in turbulent atmosphere increases on propagation, which is much different from its invariant properties in free-space, and is mainly determined by the parameters of the beam and the atmosphere. The relative M2-factor of a DHB increases slower than that of Gaussian and flat-topped beams on propagation, which means a DHB is less affected by the atmospheric turbulence than Gaussian and flat-topped beams. Furthermore, the relative M2-factor of a DHB with lower coherence, longer wavelength and larger dark size is less affected by the atmospheric turbulence. Our results will be useful in long-distance free-space optical communications.
131 citations
TL;DR: In this paper, the basic theory for treating the propagation of optical beams in turbulent atmosphere is described, and recent theoretical and experimental developments on propagation of a partially coherent beam in turbulent environment are reviewed.
Abstract: Partially coherent beam is preferred in many applications, such as free-space optical communications, remote sensing, active laser radar systems, etc., due to its resistance to the deleterious effects of atmospheric turbulence. In this paper, after presenting a historical overview on propagation of optical beams in turbulent atmosphere, we describe the basic theory for treating the propagation of optical beams in turbulent atmosphere and we mainly introduce recent theoretical and experimental developments on propagation of partially coherent beam in turbulent atmosphere. Recent progress on the interaction of a partially coherent beam with a semirough target in turbulent atmosphere and the corresponding inverse problem are also reviewed.
128 citations
TL;DR: Partially coherent beams with a prescribed phase, state of polarization, and degree of coherence display many extraordinary propagation properties and are preferred in many applications, such as particle trapping, free-space optical communications, remote sensing, optical imaging, material thermal processing, image transformation, and optical encryption as discussed by the authors.
Abstract: Partially coherent beams with a prescribed phase, state of polarization, and degree of coherence display many extraordinary propagation properties and are preferred in many applications, such as particle trapping, free-space optical communications, remote sensing, optical imaging, material thermal processing, image transformation, and optical encryption. In this review, we begin with describing conventional Gaussian Schell-model beams and partially coherent beams with prescribed phases, states of polarization, and degrees of coherence. Then we introduce theoretical models for various partially coherent beams and the methods for generating them. Finally, a brief summary is presented.
104 citations
References
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TL;DR: In this article, a Laguerre-Gaussian (doughnut) beam whose frequency is blue detuned to the atomic transition was used to trap neutral atoms in the dark core of the doughnut beam with the help of two additional laser beams.
Abstract: We have constructed a novel optical trap for neutral atoms by using a Laguerre-Gaussian (doughnut) beam whose frequency is blue detuned to the atomic transition. Laser-cooled rubidium atoms are trapped in the dark core of the doughnut beam with the help of two additional laser beams which limit the atomic motion along the optical axis. About ${10}^{8}$ atoms are initially loaded into the trap, and the lifetime is 150 ms. Because the atoms are confined at a point in a weak radiation field in the absence of any external field, ideal circumstances are provided for precision measurements. The trap opens the way to a simple technique for atom manipulation, including Bose-Einstein condensation of gaseous atoms.
781 citations
"Generation of a high-quality partia..." refers background in this paper
...Over the past several years, dark-hollow beams (DHBs) with zero central intensity have been widely investigated both theoretically and experimentally due to their wide applications in atomic optics, free space optical communications, optical trapping of particles and life sciences [1-14]....
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TL;DR: In this article, Planar as well as spherical targets were irradiated for the first time by the random-phased wave and the targets were uniformly accelerated without being affected by small-scale intensity nonuniformities.
Abstract: By converting a coherent wave to a random-phased wave, the intensity profile on a target becomes easily controllable. Planar as well as spherical targets were irradiated for the first time by the random-phased wave. The targets were uniformly accelerated without being affected by the small-scale intensity nonuniformities. The $\frac{3}{2}$-harmonic emission shows that the plasma waves at $\frac{{n}_{c}}{4}$ are only weakly excited in a spherical plasma. Irradiation with short-wavelength, random-phased beams will be suitable for compression.
603 citations
"Generation of a high-quality partia..." refers background in this paper
...It is well-known that decreasing the coherence of light can reduce speckle effects due to the intereference between different points of light in many applications [15, 16]....
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...Over the past decades, partially coherent beams have found wide applications in laser scanning, inertial confinement fusion, free space optical communication, imaging applications and nonlinear optics [15-19]....
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TL;DR: In this article, a quasi-monochromatic Gaussian laser beam propagating in atmospheric turbulence is examined by using a derived analytic expression for the cross-spectral density function.
Abstract: A partially coherent quasi-monochromatic Gaussian laser beam propagating in atmospheric turbulence is examined by using a derived analytic expression for the cross-spectral density function. Expressions for average intensity, beam size, phase front radius of curvature, and wave-front coherence length are obtained from the cross-spectral density function. These results provide a model for a free-space laser transmitter with a phase diffuser used to reduce pointing errors.
510 citations
TL;DR: The HGBs provide a convenient and powerful way to describe and treat the propagation of DHBs and can be used conveniently to analyze atoms manipulated with a DHB.
Abstract: A new mathematical model, described as hollow Gaussian beams (HGBs), is proposed to describe a dark hollow laser beam (DHB). The area of the dark region across the HGBs can easily be controlled by proper choice of the beam parameters. Based on the Collins integral, an analytical propagation formula for the HGBs through a paraxial optical system is derived. The HGBs also can be expressed as a superposition of a series of Lagurerre-Gaussian modes by use of a polynomial expansion. As a numerical example, the propagation properties of a DHB in free space are illustrated graphically. The HGBs provide a convenient and powerful way to describe and treat the propagation of DHBs and can be used conveniently to analyze atoms manipulated with a DHB.
316 citations
"Generation of a high-quality partia..." refers background in this paper
...Over the past several years, dark-hollow beams (DHBs) with zero central intensity have been widely investigated both theoretically and experimentally due to their wide applications in atomic optics, free space optical communications, optical trapping of particles and life sciences [1-14]....
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TL;DR: The quality and visibility of the ghost image are influenced by the source's transverse size, coherence width, and object characteristics, and the equation depends on both paths.
Abstract: We theoretically study ghost imaging with incoherent and partially coherent light radiation by using classical optical coherence theory. A Gaussian thin lens equation is derived for the ghost image. The equation depends on both paths. The quality and visibility of the ghost image are influenced by the source's transverse size, coherence width, and object characteristics. The differences between ghost imaging formed with incoherent light radiation and with entangled photon pairs are discussed.
250 citations
"Generation of a high-quality partia..." refers background in this paper
...Over the past decades, partially coherent beams have found wide applications in laser scanning, inertial confinement fusion, free space optical communication, imaging applications and nonlinear optics [15-19]....
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