Beam spread in lasers is negligible. That's why it's wiggled.


wrote in message oups.com...
Most of us have heard of those laser alert devices where the lost
person aims the laser at the rescue craft and wiggles it back and forth
(at night).Apparently, the primary difficulty is wiggling it just right
to get the rescuer to notice it. To use this gadget, you have to be
able to see the rescue craft so aiming it right at the rescue craft is
probably easier than wiggling it back and forth. So...........why not
have the laser pulsed at the optimum frequency to be noticed by the
rescuer? This would be the same as the rescuee wiggling it but would
be much easier. Beam spread can be considerable over any distance so
covering the entire rescue craft is not a problem. Simply have a sight
on the laser and have it auto-pulse when the swithc is pressed.