空间光通信经历了几十年的发展，已经演变出两代光通信终端，并完成多次在轨实验。概述了空间光通信的整体发展历史，详细介绍了欧洲、日本和美国的空间光通信的发展历程，并对其中较为典型的终端或实验及其关键技术进行着重阐释。简要介绍了国内的发展现状，分析了空间光通信的发展趋势，并指出技术上面临的挑战。

The space optical communications have gone through decades of development, evolving two generations of optical communication terminals, and accomplishing several on-orbit experiments. The overall development history of space optical communications is summarized, the development progress of Europe, Japan and the USA is introduced in detail, and then some of the typical terminals and experiments are stressed, as well as the key technologies. The development status in China is briefly introduced. The development trends of space optical communication are analyzed, and the technical challenges are pointed out.