What about this for a place to live
Focusable Laser Module Housing for C Mount Module with Heat Sink and LD Base | eBay
States it has a glass lens that focuses.....not sure of the coatings, etc...
There is currently a c-mount 500mw 635 for sale on the forum for $50 that supposedly comes with a corrective lens if I read correctly. I figure for a total of $66 it's worth a try...
I have done some work with C-mounts.
I got one of these diode mounts and tried it out with a couple 808nm and one 650nm 300mW. What I found is that you need to place it correctly....for some reason my 650nm still does not align quite right and cuts part of the beam...
Now as far as the lens that comes with the unit, it really does little to nothing. I would doubt that it is coated for red, perhaps IR, perhaps nothing...
I would suggest if you want to really make this thing work, have someone work up some sort of lens mount that can be put closer to the diode. It's a tall order but not out of reach.
Remember that a C-mount is completely open to the elements, take care when handling it and mounting it. Also, I personally still have questions that the "heatsink" mount for the diode is enough. There should be holes to mount a fan on the back and could help in cooling.
Good luck with your experiments....If I can come up with some photo's of my 'set-up' i'll post them.:beer:
Edit: On you question....like any other diode you may be able to push them further....you Have to control the heat though. I have degraded my 650nm C-mount because it was not correctly cooled.(when I look closely through magnification I can see one or two of the wires are "burnt" but not broken...)
Link to thread on the mounts as well.....
http://laserpointerforums.com/f46/lab-c-mount-housing-67701.html
Here are some photo's of the unit you are looking at with an IR diode in it.
[/IMG]
[/IMG]
[/IMG]
[/IMG]
[/IMG]