[Laser] "retro reflectors"

[Art]

>I plan to heat sink one to see how far it can be pushed in duty cycle.


Kerry,

BAD IDEA!

You are certainly free to do as you wish. BUT, the reason why they are 
rated for pulse only is because the lasing current (threshold current) is 
above what the diodes can dissipate when run in constant duty or even 
raised duty cycle. You might run them at 15A peak, but they might require 
8A to lase. You could run them in LED mode, but it's not likely you can run 
them at anything other than low duty cycle pulse mode. I don't think you'll 
be able to run them at any duty cycle above their ratings.

These pulse mode diodes are old technology, left over from the days before 
they figured out how to lower the lasing threshold and run constant duty 
(as modern diodes do).

You might be able to run them at liquid nitrogen temps however. At very low 
temps, the lasing current drops and the diodes produce much more output 
power for each milliwatt of input power. Further, you may find your IR 
laser now emits in the visible range if you can keep it cool enough. I'm 
not sure you will get it cold enough to allow constant duty however.

Be sure to observe safety protocols when handling any cold (liquid) gas. If 
a dewar breaks or there is a spill, the liquid will freeze human body parts 
faster than than you can say 'ooopppssss', and tissue frozen in this manner 
does not thaw and spring back to normalcy.

Enjoy.

Art