Bo-Yang Zhang

Satellite-based quantum communication is a promising approach for realizing globalscale quantum networks. However, due to atmospheric turbulence, achieving a highly efficient and stable spatial single-mode receiver, which is very important for daylight free-space quantum key distribution and more complex quantum information tasks involving quantum interference, is difficult. Here, we develop a spatial single-mode receiver with an adaptive optics (AO) system based on a modal version of the stochastic parallel gradient descent algorithm (M-SPGD) and conduct a field test of its performance over an 8 km urban terrestrial free-space channel. Our experimental results demonstrate the AO technology based on M-SPGD has a great boosting for single-mode receiver and is useful for large-scale quantum communication.