There are excellent reasons to pot mod a laser pointer:
- Reduce power of a green to use as a star pointer. Adjust from 50 mW to 30 mW depending on conditions. Brighter can interfere with dark adaptation of eye.
- Increase power to original level when substituting lower voltage batteries...
You can harvest the output lens from a laser sled assy. Lens is about 4 mm diameter, about 1 or 2 mm F.L. You get 3 for $2 with free shipping.
http://hightechdealz.com/index.php?main_page=product_info&cPath=4&products_id=16
I recommend you buy just one set and test your idea first...