Intensity fluctuations of focused general-type beams in atmospheric optics links

Yahya Baykal; Halil T. Eyyuboğlu

doi:10.1117/12.724548

13 June 2007 Intensity fluctuations of focused general-type beams in atmospheric optics links

Yahya Baykal, Halil T. Eyyuboğlu

Proceedings Volume 6603, Noise and Fluctuations in Photonics, Quantum Optics, and Communications; 660320 (2007) https://doi.org/10.1117/12.724548
Event: SPIE Fourth International Symposium on Fluctuations and Noise, 2007, Florence, Italy

Abstract

The intensity fluctuations of focused general-type beams in weakly turbulent atmospheric links are formulated and numerically evaluated. Focused general-type beams in general cover very large range of beams, however in this work we concentrate specifically on the focused sinusoidal-Gaussian, annular and flat-topped beams. The behavior of the scintillations for these beams is examined versus the focusing distance, wavelength of operation and the source size. In our formulation, atmospheric turbulence is introduced through the Rytov method where the free space field (i.e., in the absence of turbulence) at the receiver plane for the general-type focused beam is found by utilizing the Huygens-Fresnel principle. Figures are presented showing the scintillation index for focused general-type beams and collimated general-type beams. To find out the source and medium parameters that will yield favourable scintillation levels, the intensity fluctuations of the focused sinusoidal-Gaussian, annular and flat-topped beams are compared. Within the range of selected source and medium parameters, our observations indicate that the intensity fluctuations in weak turbulence tend to be the smallest for the focused flat-topped Gaussian beams and the largest for the focused cos-Gaussian beams. Gaussian, cosh-Gaussian and annular beams experience interim level fluctuations. The comparison of the scintillation levels for the mentioned types of focused beams follow the same tendency for all the propagation distances. Also, the intensity fluctuations of the focused general-type beams in turbulence are compared with their collimated counterparts. Such a comparison reveals that for all the beams at a selected source size, the scintillations are nearly the same for both the focused and the collimated cases at all the propagation distances, except for the flat-topped Gaussian beams. When focused flat-topped Gaussian beams are employed, the intensity fluctuations seem to be lower as compared to the equivalent collimated flat-topped Gaussian beam at shorter link lengths.

Citation Download Citation

Yahya Baykal and Halil T. Eyyuboğlu "Intensity fluctuations of focused general-type beams in atmospheric optics links", Proc. SPIE 6603, Noise and Fluctuations in Photonics, Quantum Optics, and Communications, 660320 (13 June 2007); https://doi.org/10.1117/12.724548

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available