From Onyx web site
"AFB® YVO4 or GdVO4 components are extremely useful for higher power in YVO4-based laser systems. Undoped end-caps increase damage threshold by separating the pump input face with the lasing doped portion. Onyx produces slabs and rods with plano or spherical end faces."
Encap, just found your answer and link, tks much, mo rep coming. I found some .5% doped YVO4 rods and some 3% doped, have been searching the net trying to find information regarding doping but so far, only info I can get goes up to 2%. Can't find application info for the higher doping level, any thoughts?