School me on Single/Multi Mode differences

[blue laser research]

What are the differences in these, pertaining to distance they can burn/focus. Beam quality .etc

Is one perferred over the other for IR spotlight purposes? The IR lasers I have all display lines of illumination.

 

[udanis]

So how about search?
http://laserpointerforums.com/f54/single-mode-multi-mode-laser-diodes-53695.html

 

[blue laser research]

So how about search?
http://laserpointerforums.com/f54/single-mode-multi-mode-laser-diodes-53695.html

Thanks, but while being very technical I do not think it answered all of my questions. I am beginning to understand the design differences but not how they will effect the actual dot, or which would be better for generating a spotlight for IR illumination.