Infrared flash?

[Major Variola (ret)]

At 10:28 PM 4/26/04 +0200, Thomas Shaddack wrote:
>But when I want a really bright flash on about 800-900 nm, what
approach
>is the best?

A 1 watt IR laser diode used for burning wood.  They show up on eBay
for ~$100.    Might start a fire though :-)   Also has pointing issues.

>What would be the best approach? The energies here are more in the
range
>of rotation/vibration changes than electrons jumping up and down
between
>the energy states. How to convert a blast of electrical energy into a
>shower of near-IR photons?

Regular tungsten driven to red but not bright, with a piece of
low-pass filtering glass over it.  You can't get rapid modulation
with tungsten, of course, but a few Hz is possible.

Years ago IR leds on baseball caps were posited for defeating
certain (eg ATM) cameras.  Don't know if they worked.