Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please
hey will that set work better than the meredith optics?
Here's the thing with prism pairs versus cylindrical lenses:
- Cylindrical lenses are for focusing (collimating) a beam in only one axis.
- Prism pairs are for reducing the width of an axis of an
already collimated beam (i.e. correcting aspect ratio).
The problem with those 638nm laser diodes is that each axis has a different divergence angle (7.5 vs 35 degree angles). So with a circular lens, one axis gets collimated, but the other still diverges. That's why you need to have separate collimation for each axis. Chances are, if you can collimate your beam, you won't have the exact optics to create a
square beam--especially given the price of cylindrical optics. So now you can take the prism pair and correct one of the axises, or at least try and reduce the aspect ratio.
So here is what I'm going to do:
1) Use cylindrical lenses to collimate both axises; 2) use the prism pairs to reduce the beam diameter in one axis if there is a mismatch (this probably won't be perfect).