jeez dude, that looks scary.
Did you do that with a carbon steerer?
Anyway, the purpose of a carbon steerer is light weight and maybe some shock absorbtion. You effectively canceled any weight savings with what you did there and it looks scary because that type of clamping is untested. You really don't know what kind of stresses that is putting on your fork.
Normally, you use a compression nut on carbon steerers. Some, like Cannondale, still use a star nut but you should do whatever the specific manufacturer suggests. Anything else can be very dangerous.