Three options are examined.

The “polished panel” optical receiver concept described here makes use of aluminum panels on the main reflector of the Deep Space Network’s (DSN’s) 34-meter antennas at optical wavelengths by polishing and coating their surface to efficiently reflect nearinfrared wavelengths in the 1,064–1,550- nanometer range. Achievable surface smoothness is not a limiting factor for aluminum panels, and initial field experiments indicate that the surface quality of microwave aluminum panels is sufficient to concentrate the light into small, but not diffraction-limited, spots at their primary focus. Preliminary analysis of data from high-quality microwave panels has shown that the light can be concentrated into 200–400 microradian cones, resulting in spot diameters of 2–4 mm at the 10-meter primary focus F0 shown in the figure, or 2–4 cm spots at F1 after magnification by the subreflector, which results in an effective focal length of about 100 meters. Three distinct implementation options are possible, with theoretically identical tracking and communications performance: