Beam wandering in the atmosphere: The effect of partial coherence

Berman, G. P.; Chumak, A. A.; Gorshkov, V. N.

doi:10.1103/physreve.76.056606

Cited by 69 publications

(63 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For a long-distance propagation or a strong turbulence, the beam radius becomes greater than the characteristic sizes of the inhomogeneities. In this case the probability of the beam to be redirected becomes small and the relative value of the wandering radius decreases [8].…”

Section: Introductionmentioning

confidence: 99%

Strong enhancing effect of correlations of photon trajectories on laser beam scintillations

Chumak

Baskov

2016

Phys. Rev. A

View full text Add to dashboard Cite

A distribution function approach is applied to describe the dynamics of the laser beam in the Earth atmosphere. Using a formal solution of the kinetic equation for the distribution function, we have developed an iterative scheme for calculation of the scintillation index (σ 2 ). The problem reduces to obtaining the photon trajectories and their correlations. Bringing together theoretical calculations and many-fold computer integrations, the value of σ 2 is obtained. It is shown that a considerable growth of σ 2 in the range of a moderate turbulence is due to the correlations of different trajectories. The criteria of applicability of our approach for both the coherent and partially coherent light are derived.

show abstract

Section: Introductionmentioning

confidence: 99%

Strong enhancing effect of correlations of photon trajectories on laser beam scintillations

Chumak

Baskov

2016

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…It determines requirements for tracking and pointing instruments of FSO system [26]. This effect is observed as a random movement of the focused beam on the photodetector surface.…”

Section: Atmospheric Effectsmentioning

confidence: 99%

Analysis of Free-Space Optics Development

Mikołajczyk¹,

Bielecki²,

Bugajski³

et al. 2017

Metrology and Measurement Systems

View full text Add to dashboard Cite

The article presents state of work in technology of free-space optical communications (Free Space Optics − FSO). Both commercially available optical data links and their further development are described. The main elements and operation limiting factors of FSO systems have been identified. Additionally, analyses of FSO/RF hybrid systems application are included. The main aspects of LasBITer project related to such hybrid technology for security and defence applications are presented.

show abstract

“…The random fluctuations in the refractive index of the atmosphere alter the propagation pathway of light beams which, in turn, affects their initial phase fronts (Andrews et al, 2005). Once light propagates through a turbulent atmosphere, the phase fronts become distorted and experience random changes in beam direction (beam wander) as well as random intensity fluctuations (scintillation) (Berman et al, 2013).…”

Section: Theorymentioning

confidence: 99%

Wind tunnel simulations to detect and quantify the turbulent effects of a propagating He-Ne laser beam in air

Augustine

Chetty

2017

Atm

View full text Add to dashboard Cite

RESUMENSe verifica la efectividad de un diseño experimental para detectar y cuantificar los efectos turbulentos experimentados por un haz de láser de He-Ne al pasar por un túnel de viento. El haz se difundió a través de una serie de componentes ópticos además del túnel de viento diseñado y fabricado en el laboratorio en condiciones controladas. La construcción del túnel obedeció a una configuración preexistente, cuya aptitud para detectar los efectos turbulentos de otros modelos se había comprobado previamente. El diseño experimental fue exitoso, ya que pudo detectar y medir las condiciones atmosféricas al interior del entorno turbulento y cuantificar con precisión las características del haz de láser. Mediante el uso de instrumentos de medición de alta precisión, se pudo medir de forma exitosa la función de la estructura del índice de refracción (C n 2 ) y el diámetro de coherencia (parámetro de Fried). Los valores de C n 2 variaron de 1.61 × 10 -16 m -2/3 a 6.77 × 10 -15 m -2/3 , lo cual puede catalogarse como un régimen de turbulencia moderado a intenso. Estos resultados muestran una buena correspondencia con los de varios trabajos que investigaron entornos atmosféricos similares, de modo que nuestro diseño fue capaz de detectar y medir con precisión las turbulencias térmicas y los efectos de la velocidad del viento en el haz de láser, utilizando para ello un interferómetro de punto de difracción. ABSTRACTIn this paper, we ascertain the effectiveness of our experimental setup in detecting and quantifying the turbulent effects experienced by a He-Ne laser beam as it passes through a wind tunnel. The beam propagated through a series of optical components as well as the in-house designed and manufactured wind tunnel under controlled laboratory conditions. The wind tunnel was built to fit within an existing setup, which has previously proven to be successful in detecting the turbulent effects from other turbulence models. For various wind speeds and temperature settings, the setup has been successful as it was able to detect and measure the atmospheric conditions within the turbulent environment and fully quantify the characteristics of the laser beam. With the use of highly accurate measuring devices, we were able to successfully measure the refractive index structure function (C n 2 ) and the coherence diameter (Fried's parameter , which can be classified under the moderate to strong turbulence regime. These results tie in well with various published works for similar atmospheric scenarios hence this setup was successfully able to fully detect and quantify the thermal turbulence and wind velocity effects on the laser beam using a point diffraction interferometer.

show abstract

Beam wandering in the atmosphere: The effect of partial coherence

Cited by 69 publications

References 10 publications

Strong enhancing effect of correlations of photon trajectories on laser beam scintillations

Strong enhancing effect of correlations of photon trajectories on laser beam scintillations

Analysis of Free-Space Optics Development

Wind tunnel simulations to detect and quantify the turbulent effects of a propagating He-Ne laser beam in air

Contact Info

Product

Resources

About