Results 261 to 270 of about 2,420,038 (307)

Turbulent Transitions in Optical Wave Propagation

Physical Review Letters, 2016
We report the direct observation of the onset of turbulence in propagating one-dimensional optical waves. The transition occurs as the disordered hosting material passes from being linear to one with extreme nonlinearity. As the response grows, increased wave interaction causes a modulational unstable quasihomogeneous flow to be superseded by a chaotic
PIERANGELI, DAVIDE, DI MEI , FABRIZIO, DI DOMENICO, GIUSEPPE, Agranat, A. J., CONTI, CLAUDIO, DEL RE, EUGENIO   +5 more
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Optical properties of a planar turbulent jet

Applied Optics, 1995
A planar heated air jet was constructed. Its flow properties were characterized and shown to be both reproducible and in good agreement with the results of turbulence theory. The optical properties of the jet were studied with the help of a 632.8-nm He-Ne laser beam.
I A, Joia, R J, Perkins, B J, Uscinski, G, Balmer, D, Jordan, E, Jakeman   +5 more
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Optical properties of turbulent channel flow

Applied Optics, 1990
We have measured the scaling behavior of the turbulent scattering of a beam transmitted through a heated channel flow and conclude that the use of He in a properly engineered channel allows for efficient operation of gas cooled disk amplifiers at average power.
G F, Albrecht, H F, Robey, A C, Erlandson   +2 more
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Optical propagation in laboratory-generated turbulence

Applied Optics, 1979
A versatile and useful facility for simulating the effects of atmospheric turbulence on optical propagation is described, and the relevant system parameters are characterized. The scattering medium is a turbulent liquid (ethanol) with the turbulence created by unstable convection generated by a strong vertical thermal gradient.
R A, Elliott, J R, Kerr, P A, Pincus
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Daytime forecast of optical turbulence for optical communications

2023
In recent years, forecast of optical turbulence has been developed for astronomical sites. It enables flexible scheduling of observations during the night, and improves the control of adaptive optics systems. Nowadays, there is also a need for optical turbulence forecast during daytime at locations considered for future satellite-to- ground optical ...
Quatresooz, Florian, Vanhoenacker-Janvier, Danielle, Oestges, Claude   +2 more
openaire   +1 more source

Nonlinear Optics and Turbulence

1992
Abstract : The ongoing and primary goal of the research is the pursuit of understanding of nonlinear processes in natural phenomena arising in optics and fluids. A considerable share of our attention is devoted to nonlinear optics, a relatively young subject, extremely rich in scientific and technological potential.
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Coding for the Turbulent Atmospheric Optical Channel

IEEE Transactions on Communications, 1982
In the presence of atmospheric or aircraft boundary layer turbulence, an optical channel may need large amounts of link margin to combat fading and beam spreading. Channel coding can reduce the average transmitter power required for reliable communication.
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Wander of an optical beam in the turbulent atmosphere

Applied Optics, 1990
A simple, analytic, geometrical optics expression for the variance of the beam displacements caused by propagation through weak refractive turbulence described by the Kolmogorov spectrum is presented. The analytical formula includes the effect of the divergence or convergence of the initial beam.
J H, Churnside, R J, Lataitis
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Atmospheric Turbulence in Optical Surveillance Systems

Applied Optics, 1967
The limitations imposed by atmospheric turbulence in the design of optical surveillance systems with slant optical paths are developed. Image blurring effects which determine scene contrast ratio are separated from spot dancing effects which determine signal-to-noise ratio. The relative position of each turbulent eddy with respect to scene and observer
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Many-parameter routes to optical turbulence

Physical Review A, 1986
The output of an externally pumped passive nonlinear-optical ring resonator is known to exhibit chaotic dynamics under variation of one or more external control parameters. The dynamics of the internal transverse laser beam profile is described, in the good-cavity limit, by an infinite-dimensional discrete-time map in function space.
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