# Experiment Prediction: How much light can pass through an opening?

The flow of current through a wire is limited to the size of the wire. Water through a pipe is limited by the size of the pipe. What about light? Is it limited in a similar way? Let's say I drill a 1,000nm hole in a piece of 1/4 inch steel. I then shine a 5mw red laser through the hole. Does the hole restrict how much light can pass through the hole at any given moment? Let's say I increase the light through the hole by adding more lasers. Will the hole slowly start to restrict light's passage. Is there a limit to how much light can "fit" through the hole at the same time? Example Experiment: I shine the laser through the hole. I then measure the light with a photo diode and let's say I get 1 volt. Now I increase the amount of light through the hole by adding another laser of the same size. Would I now see 2 volts? What if do this again? Would I see 3 volts? Would each additional laser produce the same gain as the one before it? I understand the lasers would all have to be angled toward the hole by the same amount to actually perform this test. I also understand may need to perfect the measuring device, but I think you get the point.