Eye-safe free-space laser communications

The Laser Communications Lab (LCL) of the Wright Laboratory Avionics Directorate is heavily involved in designing optical communications systems to meet our current and future military communications requirements. Due to the reluctance of many DOD agencies to adopt laser communications because of the potential eye-safety hazards associated with lasers, work is being accomplished in the LCL to develop an eye-safe laser communications system which will be powerful enough to provide communications over an extended range. This paper summarizes a system which has been designed, built and tested in the LCL using a prototype one watt continuous wave, two micron wavelength, laser diode. Also summarized is the work accomplished using the Moderate Resolution Atmospheric Transmittance and Radiance Model, MODTRAN to choose the wavelength for the design.