OSETI INTERSTELLAR LASER COMMUNICATIONS LINK (iLCL): PARAMETERS, MECHANISMS, CONCEPTS
Joseph S. Horwath
400 Oyster Point Blvd Ste 415
South San Francisco, CA 94080
Copyright: Stuart Kingsley
Can optical SETI contact, and possibly communication, be established via Electro-Optic means, with ETI "technical civilizations", who like us-potentially-might be residing within the galaxy? Specifically, can laser "Beacons" or interstellar Laser Communications Links (iLCL), be implemented with current or future, but foreseeable Electro-Optic Technology (EOT)? If so, what are the parameters, mechanisms, and concepts by which such systems could be mechanized? If indeed, electro-optic UV/VIS/IR sensors would detect signals from a remote extraterrestrial origin - from where, and from how far away, might such signals come from? How would we respond to them? The theme, here envisioned, is that a "Listen-only" strategy could/should be complemented with EOT/laser transmissions by us, terrestrials, so-as to result in a "Receive & transmit" strategy. This form of proactivity could markedly enhance the probability of ultimate successful contact. It is projected that this can be accomplished by the use of suitably configured, space-based High Power Laser Sources (sb/HPLS). Such devices would probably be operating at short optical wavelengths (VIS & UV), into diffraction limited large aperture optics, pointed with high precision and accuracy, at candidate stellar systems.
A SNR link-analysis was carried out, for such iLCL systems, in both a Pulsed and CW-mode of operation. Laser systems, using 1 MW average output power assumptions, were utilized as a base-line. Operating ranges, pulse energies, and pulse widths were parametized over a spectrum of optical wavelengths. It is shown that UV/VIS/IR Pulsed-laser systems operating in the "Beacon" or lower data-rate mode, might variously operate over such interstellar ranges, (10-3,000 LY) at imputed "Optimistic" and "Nominal"-regimes of likelihood of contact. It is recognized, that "Pessimistic"-regime ranges of 3,000-10,000 LY or more, might be required to surmount the Drake Equation probabilities to establish communicative contact. Additionally, a sufficient COEVALITY must exist to prevent evolutionary time-phase-delay, between communicating agencies from establishing and maintaining, an enduring OSETI-type Interstellar laser communications link (ILCL) contact.