Results 211 to 220 of about 3,594,215 (244)

Coherence and Fluctuations in Light Beams

American Journal of Physics, 1964
A quasithermal, quasmonochromatic lamp is described which serves as a highly degenerate light source with adjustable coherence time between 10−5 sec and 1 sec. This lamp is used for several demonstration experiments concerning the relations between coherence and fluctuations: The intensity interferometer of Hanbury Brown and Twiss is applied to measure
W. Martienssen, E. Spiller
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Universal Conductance Fluctuations of Light

Physical Review Letters, 1998
We observed that laser light, multiply scattered through small samples of optically dense colloidal suspensions, builds up anomalous long range correlations in the transmission speckle pattern. The dynamic autocorrelation function of angular integrated light intensity has two contributions, ${C}_{2}(t)$ and ${C}_{3}(t)$, which decay on very different ...
Frank Scheffold, Georg Maret
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Photosynthesis in Fluctuating Light Environments

2006
The light environment in plant canopies is characterized by rapid fluctuations in photon flux density (PFD) because of the occurrence of sunflecks. These sunflecks can contribute most of the PFD available for photosynthesis and thus the mechanisms that control their utilization can have a significant impact on the carbon gain within canopies or in ...
Robert W. Pearcy, John P. Krall, Gretchen F. Sassenrath-Cole   +2 more
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Photosynthesis in fluctuating light

2023
Light is the essential energy source for plants to drive photosynthesis. In nature, light availability is highly variable and often fluctuates on very short time scales. As a result, plants developed mechanisms to cope with these fluctuations. Understanding how to improve light use efficiency in natural fluctuating light (FL) conditions is a major ...
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Fluctuations and light scattering in thin smectic films

Physical Review E, 1993
An analysis of the layer-displacement fluctuations in thin smectic-A liquid-crystal films is presented. Explicit formulas for the displacement-displacement correlation function, taking into account the surface tension and the anchoring strength, are derived.
, Shalaginov, , Romanov
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Daily fluctuations in the detectability of dim lights by humans

Physiology & Behavior, 1986
Several aspects of retinal physiology are known to vary on daily or circadian cycles, suggesting that certain aspects of visual function might also vary. We measured absolute threshold--the dimmest visual stimulus that can be reliably detected--in seven human observers at mid-day (1200-1400) and mid-night (0000-0200), by means of standard ...
C J, Bassi, M K, Powers
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Communication with Dynamically Fluctuating States of Light Polarization

Physical Review Letters, 2002
The fast, irregular, fluctuations of the state of polarization of light output from an erbium doper fiber ring laser are used to communicate digital information. The experiments illustrate the application of a dynamical encoding and information recovery scheme that is robust to perturbations of the communication channel, a standard single mode fiber. A
Gregory D, VanWiggeren, Rajarshi, Roy
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On the classical fluctuation of a beam of light

Il Nuovo Cimento, 1957
The fluctuation of intensity of a light beam emitted by a macroscopically constant source is evaluated. The generating function of the distribution is determined exactly; it is found that the moments of the distribution are in good approximation those of a Gaussian distribution. Eecent experiments on photon coincidences are discussed.
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V Fluctuations of Light Beams

1963
Publisher Summary This chapter describes the fluctuations of light beams. Like other fluctuation problems concerned with departures from equilibrium, radiation fluctuations in an enclosure can be treated by the methods of statistical mechanics. The fluctuations of the counts recorded by a photo-detector illuminated by Gaussian light depart from ...
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Squeezing the quantum fluctuations of light

Contemporary Physics, 1988
Abstract This paper is intended to be an introduction to the field of non-classical light. Starting from a pictorial discussion of the properties of the radiation field, examples for the generation and possible applications of squeezed states of the light field are given.
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