[ATM] Wavelengths of light

[Dominic-Luc Webb]

On Fri, 3 Aug 2007, Francis J. O'Reilly wrote:

> Has anyone here tried otehr colors such as purple, a
> much shorter wavelength? Or red a much longer wavelength?

Yes, and it all depends on the overall aims. Never be afraid to
hop over to another wavelength to achieve your goal. In my case,
I am using different lasers and light sources (e.g., CD/DVD
lasers). I am matching wavelength to the low refractive index
of plate glass in (essentially) a Norman test to get a null
test for plate glass Cassegrain secondaries where I do not
want very high amplification. The current system is an RC
with a 315 mm diameter F/4.8 primary and M (amplification)
is 4.8. This permits a Null test for a hyperbola.

Dominic-Luc Webb