Part 2- I've been looking for CHEAP, 18650-powered laser pointers. Real IR ones are pretty much out of my price range. I was going to go w/ the "Violet" 404nm pointers, and depend on poor filters, or try to remove the IR filter, and use them for focused therapy devices. Some claim to be focusable devices, I would use a vid camera w/ "night shot" to see what the patterns are like.
The target of interest for me is nerves. There's a "sweet spot" centered around 850nm, so I am hoping that the 808nm source from cheaper laser devices would have enough splash that would be therapeutic. A knucklehead on YT claiming Violet laser-pointers are a "miracle medical device", and "the programming is in the holographic label they put on the side". I wanted to club him, but it got me thinking about using poorly made pointers to get closer to the coherent IR sources I wanted.
How's the knee? There's a set up using halogen lights that helped my torn rotator cuff tremendously.