The COSETI Observatory
- Optical SETI is a subset of Electromagnetic SETI covering the spectrum from the far-infrared, through the near-infrared, the visible region, to the ultra-violet. The word “Optical SETI” is NOT to be used as a synonym for “Visible SETI”. It is a superset of Visible and Infrared SETI.
- Lasers can operate throughout the infrared, visible and ultra-violet spectral regions. Although the “L” in “Lasers” stands for “Light”, there is no implication that the “light” must be visible. Thus, there are Infrared Lasers and there are Visible Lasers.
Why Optical SETI?
- Simply, lasers are superior for point-to-point, free-space interstellar communications. In the not-to-distant future, when mankind sends out probes to the outer reaches of the solar system and to nearby stars, communications with Earth will be via lasers. “Photonics”, otherwise called “Optoelectronics” or “Optronics”, will be the major communications technology of the future.