Read the regs... It says no night vision.
Night hunting is allowed in most of the state(except part of the central valley) as long as there is no big game season open. You can't take anything listed as game(even jack rabbits) Just varmint...
Basically 9v max power handheld or on the head for most the state. (not attached to the gun)
In most the desert region any power can be used. Fish and game has said the light can be weapon mounted, but you are likely to encounter LEO that don't know the law. They will take your weapon and you will be going to court.
There are some areas the prohibit night hunting by county ordinance. Like all of san diego county is closed, san benito county is closed, and use the san bernardino county shooting map to see areas in san bernardino county that are open to night hunting. Always check for local laws.
Do your research, be prepared to be stopped. I carry a copy of the regs and shooting maps. I also carry a print out from the ask a warden section of DFG website that explains weapon mounted lights.
I took hours to carefully outline the boarders of the night hunting zones. The jerks deliberately want to make it difficult to understand night hunting regs. Rather than just put a map in the regs it is pages of stuff like ...From the intersection of rush creek and highway 5, 8 miles north to tweakerville road, west 20 miles to the edge of mono county ...and on and on...
The closed area is part inside the green. THe 12v area is everything east of the pink line running along the edge of the sierra. THe 9v hand held area is the remainder of the state as I recall.
good luck, read up, and be safe.