The tower on our building in Ettlingen offers an unobstructed view towards Karlsruhe – and thus the pre-requisite for a special cross-site experiment: a seven-kilometer laser measuring range to study optical communication in free space under real-world conditions.
The atmosphere causes scattering, refraction, dispersion, absorption and other interferences. Some of this is attributable to the physical properties of gases; but most is due to suspended particles, turbulence and the like. All interference impedes robust communication and limits bandwidths, which is why adaptive optics have to compensate for these disruptive factors. We started equipping the tower room to this end in 2017. The laser measuring range will be up and running around the time of the institute’s tenth anniversary.