[TxPhysicist]

This sheds some light on the atmospheric attenuation question. I'm doubting that this was cheap, easy to obtain hardware because it seemed to me that the power needed to penetrate perhaps miles of atmosphere would have to be high. This may have been the problem they were facing with SDI, that is, ionization of the air. Thanks for the on-point post.

No problem - there is a lot of hoopla out there - let me address (if I may) a couple of points that came up in the last 30 posts or so -

1) You CAN build these in your garage, as posters have mentioned, but there's no need to - you can buy them legally for less money (unless your time is totally worthless) than you can build them. They usually come with a warranty, though not a guarantee of suitability for this particular purpose!

2) Tough to defeat, if you want the pilots to be able to see through the windows - the military goggles that protect our soldiers are designed to protect against specific wavelengths - ultimately, if you want to see out the window, visible-band lasers can get IN the window. That makes this a tough problem, at least as long as the pilots are looking through the window. One solution (used for eye safety in my own lab) is to use light barriers (i.e., "walls") and then view the objects of interest with cameras. Even when a laser "paints" the camera, no one gets blinded, and the worst that happens is that a CCD array bites the dust. This kind of solution could potentially provide a countermeasure, albeit with serious consequences to things like depth perception, etc.

[AdamSelene235]

) Tough to defeat, if you want the pilots to be able to see through the windows - the military goggles that protect our soldiers are designed to protect against specific wavelengths - ultimately, if you want to see out the window, visible-band lasers can get IN the window. That makes this a tough problem, at least as long as the pilots are looking through the window. One solution (used for eye safety in my own lab) is to use light barriers (i.e., "walls") and then view the objects of interest with cameras. Even when a laser "paints" the camera, no one gets blinded, and the worst that happens is that a CCD array bites the dust. This kind of solution could potentially provide a countermeasure, albeit with serious consequences to things like depth perception, etc.

There are some materials that become opaque at high intensity.

Silicon, for example, will experience 2 photon aborbtion resulting in the generation of free carriers which absorb. It happens quite fast.

Pity you can't see through silicon.