mirrors and lasers

[mmotyka at lsil.com]

>On Tue, 24 Jul 2001, Eugene Leitl wrote:
>
>> On Mon, 23 Jul 2001, Jim Choate wrote:
>> 
>> > Maybe. But even mirrors can be burned through by a laser. And then we've
>> 
>> Jim, why are you trying so hard to make a complete fool out of yourself,
>> in a public forum?
>> 
>> A chemical laser needs active optics to track your remote target. What do
>> you think that optics is made from, unobtainium? Do you understand basic
>> laws of optics? I recommend purchasing a 15 W laser (and a pair of
>> matching protection goggles), and then use it to ignite a match from a
>> close distance, and then over a few km, preferably during summer in your
>> native Texas. You could target the beam towards a projection wall, and
>> watch it with a pair of binoculars. It will be quite instructive.
>
Sure but take some dramamine first if you get motion sickness.

>
>The optics used for focusing are NOT mirrors, they are (hopefully)
>transparent at the frequency under use. A mirror on the other hand is
>required to be OPAQUE with respect to transmission, we want full, 100%,
>reflectivity. That means that every photon that hits that mirror
>interacts, loses some energy, and gets re-emitted.
>           ^^^^^^^^^^^^^^^^^
>
Are you implying that the wavelength for incident photons changes upon
interaction with the mirror?

The energy loss at the mirror is lost photons not altered wavelengths.
The lost photons have varying fates.

Mike