The basic free-space optical communication system includes at least two satellites. To communicate between them, the transmitter satellite must track the beacon of the receiver satellite and point the information optical beam in its direction. Optical tracking and pointing systems for free space suffer during tracking from high-amplitude vibration because of background radiation from interstell...

Free Space Optical (FSO) communication is a very recent and emerging technology to establish broadband wireless data transmission system using modulated optical beams. The adoption of FSO system is mainly needed when any physical connection between the transmitter and receiver is practically impossible and where high bandwidth data transmission is expected. The performance of FSO communication ...

Mobile FSO Communication links have gained significant attention over the last years due to their increasing maturity. They are used in point to point link scenarios where the high gain in power efficiency and datarate is crucial, compared to state-of-the-art RF links. The Optical Communication Group of German Aerospace Center’s Institute of Communication and Navigation is conducting research a...

Free space optical communication systems have special privileges in comparison with radio transceivers in last-mile connections. Some of These features are high security, low power consumption, extremely high bandwidth and low interference. The fact that the interference free systems are one of the nowadays challenges, as well as the stems and sources of interference were investigated in this r...

We demonstrate, through numerical simulations, that an appropriately chosen nonuniformly polarized coherent optical field can have appreciably smaller scintillation than comparable beams of uniform polarization. This results from the fact that a nonuniformly polarized field acts as an effective two-mode partially coherent field. The results described here are of direct relevance to the developm...

We present the optical design of a laboratory demonstrator for a low-order adaptive optics system with possible application to improving the performance of a free-space optical communication system. The initial design includes a Shack-Hartmann wavefront sensor with high-speed CMOS camera and a 37-element membrane mirror.

Mobile Optical Free-Space Communication (MFSO) downlinks from observation platforms in low earth orbit or in the atmosphere will allow nearly undetectable high-speed data links with small and low-power laser communication terminals. Several research institutions and companies are developing MFSO terminal technology for application in tactical and strategic communication scenarios as well as for...

In our continuous variable quantum key distribution (QKD) scheme, the homodyne detection set-up requires balancing the intensity of an incident beam between two photodiodes. Realistic lens systems are insufficient to provide a spatially stable focus in the presence of large spatial beam-jitter caused by atmospheric transmission. We therefore present an improved geometry for optical tapers which...