Larry Dighera wrote:

On Fri, 28 Jan 2005 11:53:03 +0000, 10Squared
wrote in ::

Laser device in question has a rated power of 5 mW.

Actually, some are available with over 10 times that power:
http://www.wickedlasers.com/products.php

However, as you assert, they are probably still incapable of
inflicting retinal damage at the distances involved when aimed at an
aircraft in flight.

OK, let's see what happens with their most wicked laser. I see the Extreme
Phoenix with a power rating of 500mW. The quoted beam divergence is 1.2
mrad. Assuming a distance of 1 km,

a = 1.2 mrad
tan a = x / 1 * 10^3
x = 10^3 * m * x tan a
tan a =~ a
x = 1.2 * 10^3 * 10^-3 * m = 1.2 meters

To be conservative, let's use the beam divergence of only .5 mrad, or .5
meters at 1 km:

..5 m = 50 cm
p = 500 mW / (3.141 * 25 * 25 * cm^2)

Your 500 mW laser has a power of about .25 mW/cm^2 at 1 km. Again, much less
than the MPE for constant exposure. That brings up another point: Who is
going to stare at a laser? Brief exposure is uncomfortable and will cause
you to look away quickly, so MPE equation #2 is probably the one that
applies.