Relationship between wavelength of light and size of hole it can go through?

[Aeroslicer821]

Doing some reading into photonics and nanophotonics. It seems that if a hole is smaller than the wavelength of light, then the light cannot go through the hole. For example, if a hole is smaller than 570nm (green), then green light and light with wavelengths less than 570nm can pass through the hole but red (750nm) cannot pass. I do not understand why that is. I'm using the classic analogy of waves at sea to picture photon behavior. I would think that amplitude would be the limiting factor since a low lying bridge would block waves taller than it. The wavelength of the waves would not matter at all right?

 

[Valerie Park]

The analogy of waves at sea is a good one, as the behaviour of light and sound waves are similar. However, the difference between light and sound waves is that light waves have a finite wavelength. This means that if the diameter of a hole is smaller than the wavelength of light, then the light cannot pass through it. The reason for this is that the size of the hole determines the maximum amount of energy that can be transmitted through it. When the wavelength of light is larger than the size of the hole, some of the energy of the light wave is blocked, and so the light cannot pass through it.