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A level Physics diffraction of light

Hi, I’m not really sure how to visualise light interfering with itself and forming bright and dark fringes, could someone please tell me if I’m imaging it right from this picture, I know I’ve probably not drawn it correctly in terms of path difference and stuff? If not can u suggest any good pictures/animations I could look at?

Also please can someone explain to me the differences in the interference patterns produced by single and double slits and why they look different, because I don’t really understand.

Ugh anyone else just hate the waves topic lol?

Thanks!

(edited 3 years ago)

Reply 1

Sinnoh

Think of the light as circular wavefronts, like waves diffracting through slits. Your diagram doesn't really explain why the interference occurs at certain points.

Here's a nice video:

Reply 2

Sinnoh

As for the difference between single slit and double slit diffraction patterns, well this is where you really start going down the rabbit hole of optics. You have to treat each point on a wavefront as generating its own spherical wavefronts, where these spherical wavefronts interfere (see the diagram on this wiki page). This is what makes diffraction patterns look the way they do.