Temporal analysis of laser beam propagation in the atmosphere using computer-generated long phase screens
Temporal analysis of the irradiance at the detector plane is intended as the first step in the study of the mean fade time in a free optical communication system. In the present work this analysis has been performed for a Gaussian laser beam propagating in the atmospheric turbulence by means of comp...
| Authors: | , , , |
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| Format: | article |
| Publication Date: | 2008 |
| Country: | España |
| Institution: | Universitat Politècnica de Catalunya (UPC) |
| Repository: | UPCommons. Portal del coneixement obert de la UPC |
| Language: | English |
| OAI Identifier: | oai:upcommons.upc.edu:2117/118044 |
| Online Access: | https://hdl.handle.net/2117/118044 https://dx.doi.org/10.1364/OE.16.002206 |
| Access Level: | Open access |
| Keyword: | Optical communications Atmospheric turbulence Gaussian beams Laser beam propagation Laser beams Power spectra Scintillation index Comunicacions òptiques Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Telecomunicació òptica |
| Summary: | Temporal analysis of the irradiance at the detector plane is intended as the first step in the study of the mean fade time in a free optical communication system. In the present work this analysis has been performed for a Gaussian laser beam propagating in the atmospheric turbulence by means of computer simulation. To this end, we have adapted a previously known numerical method to the generation of long phase screens. The screens are displaced in a transverse direction as the wave is propagated, in order to simulate the wind effect. The amplitude of the temporal covariance and its power spectrum have been obtained at the optical axis, at the beam centroid and at a certain distance from these two points. Results have been worked out for weak, moderate and strong turbulence regimes and when possible they have been compared with theoretical models. These results show a significant contribution of beam wander to the temporal behaviour of the irradiance, even in the case of weak turbulence. We have also found that the spectral bandwidth of the covariance is hardly dependent on the Rytov variance. |
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