Abstract

Microradian tracking and pointing errors significantly affect the link performance and the bit error probability in free-space optical communication. This paper proposes the measurement method for point-ahead angle and coalignment error, which can significantly mitigate the tracking and pointing error, thus reduces the power of the free-space optical communication system. By using technologies of corner cube reflector, off-axis reflecting telescope, vacuum long-light path and anti-interference support structure design, microangles can be measured accurately, especially the coalignment error angle which is formed by two wide, incoherent beams nearly antiparallel to each other. This paper introduces the measuring equipment's structure, together with the measurement method and theoretical measurement model. The measuring accuracy analysis indicated that the measurement uncertainty of both point-ahead angle and coalignment error was superior to 0.2 μrad and the validation experimental results proved that measuring accuracies of point-ahead angle and coalignment error are all smaller than 1 μrad.

Validation of pre-compensation under point-ahead-angle in a 1 km free-space propagation experiment

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Point-ahead demonstration of a transmitting antenna for satellite quantum communication

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Capacity Analysis of Dual Amplify-and-Forward Relayed Free-Space Optical Communication Systems Over Turbulence Channels With Pointing Errors

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