Re: how to deliver and focus

Leonard,

One more input, my laser is a Synrad 48 with M2 = 1.2.
I have many question for you if you have the time:
- which formulas did you use, with mine I have other results. If you
used a program, could you send me the file, at the university there are
many optical software I could take a look at;
- which is the best way to place the lenses, I mean which face of each
lens should the laser beam reach first? The concave or the plane one
the plano-concave? On the meniscus? On the plano-convex?
- if I "focus" my BE at 10m as you said, will I affect the diffraction
limit spot size due to the long focal length of the system?
- can I consider that my beam is on a waist just out the laser?
- up to which lens diameter can I consider good a meniscus lens to have
a good focus (considering the spherical abberration)? Or, when do I
really need an aspheric one?
- if I consider a 10 meters long system, which could be the BE ratio
that makes me have an almost constant beam size all along, as in the
example you made for the 20m system? I think that 23.7, 22.7 and 23.5
could be considered "constant", so I don't need to move my BE to adjust
its focusing power when I want to deflect and focus a beam at 4 meters
or at 16 meters instead of 20m, but I only have to place the mirror in
the path and deflect the beam on the focusing lens.
- from your experience, compared to a generic ZnSe meniscus lens, an
aspheric ZnSe one how much could cost? 1.5 times? 2 times? more?
Thanks, Marco

.

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