Re: ATM rough polished surface

[schmidt@coyote.csusm.edu (Michael Schmidt)]

> I do suspect
>that the 3 micron particle size in my CeO (Rhodite 90 from Universal
>Photonics) might have something to do with this situation.

I kind of doubt it, though I'm no expert. Looking through the Universal
catalog, almost all rare earth oxide polishing compounds have particle
sizes above 2.0 micron. Lensmax R, which I believe I have heard some on
this list recommend, has an APS of 3.5 micron. Rhodite 400, 904 and 906 are
all recomended for "precision optics" with 2.5 micron particle sizes, as is
SuperCerRite 415K, with an APS of 2.2 micron. The products with <1.0 micron
particle sizes are recommended for uses with extremely low surface
roughness readings (under one angstrom) with quartz and the like. (The kind
of surfaces which Bratislav said require professional expertise, and which
are a waste when the usual non-ion-beam-annealed aluminizing subsequently
makes them rougher.)

I have just started using Universal's #85 liquid (1.5 micron particle
size), and it seems to work quite well. It FEELS 10x better than the stuff
I got in my 6" kit from Newport--but I don't have any surface reflectivity
measurements to give you. The nice thing about it is that you don't have to
buy 44 lb. of it.

Michael Schmidt
California State University, San Marcos
San Marcos, CA