From: Yvan Dutil (Yvan.Dutil@sympatico.ca)
Date: Mon Feb 04 2002 - 17:39:44 PST
This is what I got from my archives:
Power:
The green beacon component of the beam is produced by a 40 watt
frequency doubled YAG laser and the invisible signal component is
produced by a 2.5 watt infrared diode laser.
Maximum switching rate (on-off)?
The beacon component is fixed at 20khz. The signal laser transmits
data at 115kb/sec. It works the same way your laptop transmits from
the infrared port. So, we are merely transferring files from one
computer to another over an infrared link but the transmitter is
connected to our high power infrared laser so the data is also sent
out over the laser beam.
Wavelenghts:
The frequency doubled YAG laser is 532nm and the infrared diode laser
is 810nm. These wavelengths transmit efficiently through the
atmosphere.
Optical set-up?
The laser light is carried to the beam collimator through fiber optic
cables. The beam collimator is suspended in the missile silo by
steel aircraft cables and is self-leveling so that the beam points
straight up.
You can got an idea of the whole thing in action from this website:
http://www.showlasers.com/starlite.html
The detectability of this laser is quite low. With our actual technology
a Keck can detect another Keck at few tens parsecs, if a laser beam
of 60 kW is used. Our communication link is about a factor a million
poorer due to smaller lunch telescope and a weaker laser. ET would
need a km-class telescope at to catch us.
Yvan Dutil
LARRY KLAES a écrit :
> Wow - can you go into details on the laser systembeing used for the
> transmission? How powerful is it?If you can't point it accurately,
> why are you using it? Presumably for a civilization more advanced than
> ours,aiming a communications laser at another star systemwould not be
> the problem it is for us at present, so intheory Optical ASETI should
> work for them. Larry
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