Air Force Turns 747 Into Holster for Giant Laser (washingtonpost.com)

[Eugene Leitl]

On Tue, 24 Jul 2001, Jim Choate wrote:

> The optics used for focusing are NOT mirrors, they are (hopefully)

Okay, a have a chemical laser, something which burns tons of fuel
(deuterium/fluorine) in a second in a resonant cavity. It is hence a not
very small cavity. The wavelength is IR, several microns. This is
high-power optics with a giant aperture (because, you don't want your
optics to suffer the fate of your target, and because the resonant cavity
itself is huge).

Lenses don't like giant fluxes, either. Even a ruby laser pulse can break
optics, or the rod, if it has a blemish. Lenses are *HEAVY*. Lenses are
not flexible, so you can't use them for tracking. Lenses don't do very
well when we're talking about few um IR.

So what that leaves you with is an active mirror optics.

> 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.

Jim, I fear that bullet accident you had took a chunk out of one of your
frontal lobes. Or at least lead to a hemorrhage to a lesion in that area.
Have you ever had a MRI screen done? I'm serious.

> I have a half dozen lasers, thank you very much.

-- Eugen* Leitl <a href="http://www.lrz.de/~ui22204/">leitl</a>
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