Misalignment loss of Free Space Optic link

This article deals with few described loss which can appear in Free Space Optic (FSO) link. It is a misalignment loss which comes on by inaccurate installation of FSO heads. A calculation of this loss is based on power budget. The calculation of misalignment loss was done for professional FSO link which is installed in campus of VSB-Technical University of Ostrava. Results showed that a small misalignment from a straight line causes relatively great misalignment loss.