If it has yet to be, I'm sure that an upper bound can and will be calculated. The SAM/OAM properties that are being exploited here are physical phenomenon that

If it has yet to be, I'm sure that an upper bound can and will be calculated. The SAM/OAM properties that are being exploited here are physical phenomenon that conform to quantum mechanics just like everything else. We're talking about photons here that have physical/dimensional properties -- therefore, there WILL be an upper bound. I agree with user:recursive that "infinite" is a bad choice of wording.