Don Foreman wrote:
On 19 Nov 2004 16:28:53 GMT, Ian Stirling
wrote:

So your sapphire lens will be a refractor as well as a heatsink?

No, it's just a planar window.
I can just about deal with slicing a bit off a boule to get a nice flattish
slice, and then machining it to diameter and polishing.
Figuring into a lens would be a bit more than I can do.