Calculation of Angular Deflection Limits of a Mobile Free-Space Optical Link Beam

Abstract

The paper describes the effect of optical beam angular deflection on the power received by the receiver of a mobile free-space optical (FSO) link. Permissible fluctuations in the power received were studied on a steady model of the FSO link. It was assumed that these fluctuations were caused by oscillations of the optical beam across the receiver aperture. The formula for beam angular deflection limit was derived for two different types of optical intensity profile. The task was solved for two different types of atmosphere. The first type of atmosphere was considered a homogeneous and lossless environment. In the second type, atmospheric radiation attenuation was included in the calculations. Also, this article includes graphs of dependencies of the angular deflection limits upon the distance between the link stations.

Keywords

• Free space optical link
• steady model
• angular deflection of the beam
• power fluctuations
• optical intensity profile
• power budget