Past progress and future advances in space laser communications

The history of space laser communication is sketched. Three steps to establishing a link between platforms-acquisition, tracking, and communication-are described. It is suggested that future advances will greatly ease the tight tolerance requirements and bring down laser communication terminal costs as well as allow small aperture characteristics of space-based systems. This forecast based on rapid advances in semiconductor laser technology, especially at the GaAs laser wavelength. Also important will be the use of wide beams and smaller optics, coherent laser arrays, systems-on-a-chip, and MOCVD growth technology. Technology advances will make systems smaller, lighter, and far less expensive