Mark Rand wrote:

(...)

I got the impression that the object was to "roughen" the surface. This would
make the tungsten a better emitter. As they said, if you have good control of
the size and spacing of the asperities, you will be able to selectively change
the emissivity for different colours.

"Though Guo cannot yet make a simple bulb shine pure blue, for instance, he can
change the overall radiated spectrum so that the tungsten, which normally
radiates a yellowish light, could radiate a more purely white light."

You can do the same thing without a laser. Just push more power into the
bulb and the color temperature will shift upward. Bulb life suffers, though.

If they merely wanted to selectively
thin the filament, it would be orders of magnitude cheaper to do it when
drawing the wire.

OK, but how do I justify this nifty femtosecond pulsed laser then?

Gotta stay focused on the goal here. VBG

Creation of that roughened surface means redistributing filament
tungsten, yes? Subtract some here, add some there?

I'll bet you a dollar that we don't hear anything from Chunlei Guo or
University of Rochester regarding bulb life tests.

--Winston

--

We now return you to the economic collapse, already in progress.