LARGE M-ARY PULSE POSITION MODULATION AND PHOTON BUCKETS FOR EFFECTIVE INTERSTELLAR COMMUNICATIONS

Monte Ross

Laser Data Technology, Inc.

Abstract

Very low duty cycle short pulse high peak power laser modulation enables sending of signals great distances with low average power and high efficiency. Significant information can be sent by each pulse in digital pulse position modulation when M is very large. Direct detection can be utilized, enabling use of photon buckets, because the signal energy in a short pulse can overcome the generated noise by the star's spectrum. Exact optical frequency knowledge is not required because of the high background discrimination of the short pulse approach, although Fraunhofer lines offer possible choices. Pictorial data is feasible and readily reconstructed using this modulation approach. The ability to use photon buckets enables the construction of large area collectors at low cost.

17 Pages

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