Lens vs. Prisim

[planters]

I'm intending to try to experiment with a prism pair to expand a stack of 6 x 445 beams. Am I right in ordering a set of 45x45x90 prisms, magnesium fluoride coated and adjusting the pair for minimal or no beam deviation. Then I assume I can fine tune their relative angles to adjust the beam expansion to what ever I wish ie 1.5 to 2.0? Any tricks? Different prisms?

[logsquared]

I personally haven't tried 45X45X90 prisms. I think 30X60X90 is better for anamorphic correction. When used to expand, the beam will leave the prism closer to normal incidence giving lower losses due to reflection.

[planters]

That's what I needed to know. Thanks

[jenny]

aspheric lens could also be used for collimating. The far field spot is little better

[planters]

Not sure how the far field spot compares, but do you have direct experience with both methods? And do you mean a radially symmetric aspheric or a cylinder?