Wavelength selection on FSO-links

The objective of this paper is to show the latest results obtained for free space optics (FSO) within the EU COST Action IC0802 and within the European Space Agency (ESA) contract. First, the FSO technology is briefly discussed and some performance evaluation criteria for FSO are provided. Some optical signal propagation experiments through the atmosphere (including the recent investigations in satellite application for FSO) are also documented. In the main part, considerations on suitability of different optical wavelengths are brought into question. The wavelength selection is dependent on the desired application and the atmospheric effects as well as on the availability of receiver and transmitter components. Discussion on the available receiver(s) and transmitter(s) focus on advantages and costs of the different available systems. In the final part, the latest practical results (carried out within the COST Action IC0802) on modelling of the FSO channel under fog conditions and other atmospheric effects are examined.