NASA and ESA to communicate with lunar orbiter using lasers
Geege Schuman stashed this in NASA to Me
Lasers have already proven capable of carrying enormous amounts of data in fiber-optic cables and engineers believe that if they could be used in space communications, they could carry up to 622 megabits per second (Mbps) of data. Another advantage of lasers is that they use a smaller wavelength than radio by a factor of 10,000. This means that lasers can be aimed in a narrow beam and need very small antennas compared to radio for the same signal strength. All of this means smaller sets at both ends with a subsequent cost savings. Furthermore, the narrowness of a laser beam allows for much more secure communications.