Is it possible to trap light?

You make two metallic semi-spheres, and polish their inner surfaces to near-perfection. Then you drill a single hole into one of them, and join them together. What happens when light is shone at the apperture? Can you make light, somehow, enter, but do not exit, with some sort of one-way mirror?

A variant of this is not to drill a hole, but put a light source inside the sphere. There would be two choices here, if the light source had a power source, or not. in this case you would need get wiring out.

Another variant is to take a straight fiber optics and somehow, make a closed loop with it. This should be very difficult considering how hard it is to make fiber optics connections.

There are two motivations for this idea: store energy and explore unique phenonena.

Honestly I have not followed much of the cannon work in this subject. A quick search reveals that many scientists work on this very problem. I've read some time ago, briefly, that there are experiments where people shone high-power lasers into golden devices called hohlraums, and that allowed then to observe energy-to-matter conversions. It is mind-blowing. Still need to do much study to understand that. I'm really curious to know what happens when the light density increases over a volume.