We study the Q-factors of whispering gallery modes on the surface of standard optical fibers using both spectral and ring-down measurements and show that annealing by the fire torch yields Q-factors higher than 10 7 . In this case, however, variations of the effective radius are introduced, that make the mode spectrum complicated as a number of modes with a nonzero axial component of the wave vector appear. We demonstrate that tapering the fiber sample allows to evade this complexity and to build up an efficient filter operating in transmission.

We investigate the possibility to evaluate the fading statistics, and thus the availability of an adaptive optics corrected satellite to ground optical link using only four integrated turbulence parameters that are easily measured.

With the development of optical links for space-ground communications comes the need to mitigate the effects of the atmospheric turbulence to guarantee a lossless connection. By having a network of addressable ground stations we want to guarantee to always target a point where the link is available. For this to work, we need to be able to predict the forthcoming link availability for each station while keeping costs low. We have developed a method that allows, in the geostationary case, to obtain the power margin on the link without exhaustive knowledge of the turbulence state. In this work, we show that the sole knowledge of 4 integrated parameters of the turbulence profile (Cn²) and associated wind profile, which can be measured with low-complexity instruments, provides us with enough information to entirely describe the statistics of the received optical power after an adaptive optics correction. We further develop the method to take into account digital mitigation techniques (interleaving and numerical error correction) and obtain the link power margin with a maximum error compatible with current assumptions made in commonly used link budgets.