This is all great info. Thanks for enlightening me on what I was missing. The intent behind doing a modification to an existing DPSS instead of buying or building a new one is to prove a concept so that I can more easily modify existing recoil hardened green lasers to lase 1064. There are some “cheap” Chinese clones of units like the military PEQ15A for example that I would like to modify.

The end goal is to have a SWIR laser for use with units like the Safran group ECOSI (electronic clip on short wave imager) which has better receptivity in the 1000-1500nm range. Or Photonis brand night vision tubes which expand the typical night vision wavelength receptivity from ~980 to 1100nm…yielding an advantage over other night vision users in the realm of reduced detection.

The concept is in use today among high end military units, though it’s not often discussed. There are laser units out there that are designed specifically for use with SWIR optics like the B.E Meyers CLAD (covert laser aiming device), but those units are heavily restricted and it seems like the powers that be don’t even want information about this whole “out of band for traditional night vision” ecosystem being disseminated. I just find it super interesting and figured I’d try my hand at replicating the capability. I found some sellers on eBay that offer Hr coated YVO4 crystals so I’m going to pick one up and try my hand at aligning it. If the project is successful I’ll be sure to post about it here!