So in my story, I'm trying to develop a plausible freeze ray. Now many people suggest liquid helium, but it seems to have a number of practical setbacks, such as being hard to obtain, needing vast quantities, and high pressure dispersion of it to actually freeze someone. Not to mention, a good portion of it would mostly likely evaporate into the air on impact. I suppose I could fall back on it if need be, but what about something more effective like Captain Cold's gun? The closest thing we have to that is laser cooling (https://youtu.be/SDqCx4FiJSo).
Laser cooling is the use of momentum from a photon from a laser to counteract on the movement of an atom, thus bringing it down to temperatures slightly above absolute zero. There are multiple methods of laser cooling, but the most common method is Doppler cooling, in which 2 lasers each on 3 axises are fired opposite each other (check the picture).
Laser cooling has been used to cool individual atoms, a gaseous cloud of atoms (https://arxiv.org/abs/1705.03421), and even a coin-sized object (https://news.mit.edu/2007/super-cool). The problem is that all these experiments were conducted in laboratories with controlled environments, namely that the atoms were in an optical cavity of sorts, heavy machinery, and still hasn't been tested on something around the size of a human. We're not trying to do a rigorous lab experiment here, we're trying to freeze a superhero (who's essentially a man-sized reptile) dead in their tracks at the pull of a trigger.
So with all this in mind, what's the best way to go about this?