Hi,
maybe somebody who knows about goebel mirrors can have a look at this picture http://www.labx.com/v2/adsearch/morepics.cfm?chpics=1&adzone=388000&pic=388529&cn=3&adnumber=388529 and tell me what kind of mirror system this is; I know that the housing contains a single mirror which let's me believe that a diffracted parallel beam is produced (parabolic type); however, the beam collimators indicate that it may be an ellipsoidal type (single reflection) mirror which I am actually interested in; also, I remember from a discussion that those mirror surfaces degrade, in other words, is that the reason why people get rid of it? Thank you L. Keller CAMET Research Goleta, CA