Interstellar communication: Short pulse duration limits of optical SETI

Optical SETI At Harvard-Smithsonian

A high-intensity pulsed laser, teamed with a moderate sized transmitting telescope, forms an efficient interstellar beacon. To a distant observer in the direction of its slender beam, such a laser transmitter, built with “Earth 2000” technology only, would appear (during its brief pulse) a thousand times brighter than our sun in broadband visible light; even at ranges of 1000 light years a sing...

Limits on Interstellar Messages

An All-sky Optical Seti Survey

We present plans for an all-sky search for pulsed optical SETI beacons at Agassiz station in Harvard, Massachusetts. We will use a 1.8 meter f/2.5 spherical “light bucket” (2-3 arcmin resolution) focused onto a multi-pixel camera consisting of sixteen 64-pixel photomultiplier tubes (with pixels measuring 1.5 arcmin on a side) in two matched focal planes. It will observe a 1. ◦6× 0 . ◦2 patch of...

Optical SETI with NASA’s Terrestrial Planet Finder

NASA’s space-borne nulling interferometer (the Terrestrial Planet Finder – TPF) will look for the traces of early life in the infrared spectra of extrasolar planets, beginning in roughly 2010. We point out that this instrument will also be sensitive to deliberate laser transmissions from a technologically advanced civilization. A kilowatt-class infrared laser with a 10-m beam director would pro...

Quantifying the limits of unidirectional ultrashort optical pulse propagation

In this paper we explore the limits of the unidirectional pulse propagation equation (UPPE) in general nonlinear media. Our main aim is to investigate under which physical conditions two-way propagation becomes significant, and leads to a breakdown of the unidirectional approximation. Using a spectral constraint appearing in the derivation of UPPE we derive a first correction which renormalizes...