Use of Optical Amplifiers in GEO-HAP free space links

By the use of optical Erbium Doped Fiber Amplifiers (EDFA) in space communications it is possible to exploit the large capacity offered by the optical link, with a considerable reduction of transmitted power. A novel optical system for stratospheric communications is proposed. The link from a stratospheric platform to another one is carried out within the optical domain, thanks to the presence of a GEO that ensure the optical amplification. The optical preamplifier on the receiver end, is the key point for the system design: it must ensure the proper gain to the signal without introducing limitative Spontaneous Emission Noise.