A process for optically transmitting data to a remote receiver includes receiving a stream of input data signals and modulating a mid-IR laser by direct modulation with a waveform whose sequential values are responsive of the data signals of the stream. The direct modulation includes pumping the mid-IR laser to produce high and low optical power levels in response to different ones of the values. The process also includes transmitting output light from the modulated mid-IR laser to the remote receiver via a free space communications channel.
 The U.S. Government has certain rights as provided by the terms of contract Nos. DAAD19-00-C-0096 awarded by DARPA and the US Army Research Office and by the terms of contract No. DE-FG08-99NV13656 awarded by the US Department of Energy.