Can Unity Physics Engine simulate electromagnetic Radiation (e.g., microwaves, gamma-waves, etc)?

This is a very specific need, and no, there's nothing quite like this in Unity. The only thing approaching this is the SoundListener system that allows the simulation of both the speed of sound and the Doppler effect. While it's close to the issues you have here, it's a system specialized for a single listener, not millions of pixels.

There's is no such thing as "real light" in unity. A shader simulating a black light is just as fake as a shader simulating a non-UV light. Unity strays very far from simulating any kinds of physics realistically, and like most engines out there, is just a rough approximation.

Seeing radiowaves is not easy in real-life, as the detector's resolution is dictated by the wavelength of the radiation. So if you wanted to be realistic, your glasses would need antennas dozens of meter in width. If you don't care about that, you can simply have multiple types of light that you enable or disable. Using shaders you can simulate fluorescence for black light.

Unity doesn't just use RGB, but definitely doesn't use wavelength to describe light, which is neither a performant approach nor an interesting one. Your computer screen couldn't even display some of the most saturated colors in the real world, no point in computing something that can't be shown.