[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
[ATM] LED source?
Hello all,
A green LED may be better because the eye is most sensitive in this
region
The light from an LED isn't monochromatic, so the fringe contrast in the
interference test is reduced
At the moment I'm experimenting with the laser from a pointer for the
interference test. If you remove the lens this produces a beam with a width
of about 10°, sufficient for most mirrors. There's no shortage of light.
If you use a 1mw module there'll be no danger to your eyes from the
reflected light. Don't look into the laser directly!
Best wishes, Jerry
-----Ursprüngliche Nachricht-----
Von: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] Im Auftrag von
David Weinshenker
Gesendet: 27 November 2007 06:31
An: atm@atmlist.net
Betreff: [ATM] LED source? \ Re: TDE on a 6f6 mirror
Mike Lockwood wrote:
> About this time someone will ask if the blue LED provides more
> accurate test results because the wavelength is shorter, and of course
> the answer is no because the accuracy depends on the geometric
> placement of the knife edge.
Speaking of LED's, do they form a useful illuminant for testing
mating surfaces with interference fringes, or is something more
specifically monochromatic required for that to work properly?
-dave w
_______________________________________________
ATM mailing list http://www.atmlist.net/
_______________________________________________
ATM mailing list http://www.atmlist.net/