diogenes500@gmail.com
Oct12-06, 04:13 AM
Hello,
I'm trying to use a three lens zoom lens system (one -100mm FL lens
between two 500 mm FL lenses) as a variable magnification beam
expander. As the equations dictate I'm putting the positive lens at
(3/4)*500 mm away from one another. I have a pretty well collimated
beam going in (over a couple meters the radius expands by a factor
around 1.5) but when I put the beam through the zoom lens the output
beam strongly diverges when the negative lens is in the position where
the beam should be de-magnified most strongly, and is more or less
convergent when the negative lens is in the other extreme position.
Since the waist was basically collimated going in I thought it should
be collimated when coming out.
Maybe a zoom lens can't be use for this purpose? Do I need one or
more further components? Any thoughts would be appreciated, thanks in
advance.
I'm trying to use a three lens zoom lens system (one -100mm FL lens
between two 500 mm FL lenses) as a variable magnification beam
expander. As the equations dictate I'm putting the positive lens at
(3/4)*500 mm away from one another. I have a pretty well collimated
beam going in (over a couple meters the radius expands by a factor
around 1.5) but when I put the beam through the zoom lens the output
beam strongly diverges when the negative lens is in the position where
the beam should be de-magnified most strongly, and is more or less
convergent when the negative lens is in the other extreme position.
Since the waist was basically collimated going in I thought it should
be collimated when coming out.
Maybe a zoom lens can't be use for this purpose? Do I need one or
more further components? Any thoughts would be appreciated, thanks in
advance.