636 Project

[steve-o]

Hi All,
I bought a few samples of the new Mitsubishi 636 nM 150 mW laser diode.
I've had fairly good luck so far using 1 aspheric lens pulled from an old PC CD reader. It's mounted about ~0.3mm from the can window. The slow axis is great but the fast axis is fairly divergent. It produces a line (rectangle)on the wall instead of a dot (not too visible in the pics) of about 2mm x 55mm at 14 feet from the lens. Some suggestions for correction were rod lenses but I'm unclear as to which size to use, but this is fun building a laser from scratch (sorta -cant build the diode). The 636 nm is a real nice color I think. It's kind of orangy-red like a hene..
picys:

[victorzhao]

You need play the lens position specical on Z to get best collimation, you could get image with aspetion ratio about 1:4 or less dependent on diode you use. You check the collimation you can place on flat surface at different distance along the beam to try find the same size of image.

if you just care of square image at certain distance, you could just play Z position. The accuracy is in less than .1 mm.

Hope this helps.

[steve-o]

Thanks V,
Good info.
I've got it pretty well under control I think (altho some losses) --here's the thread:
http://www.photonlexicon.com/forums/...ad.php?p=47188