Diffraction (1 Viewer)

[StudyOnly]

Hey everyone,
I wanted to know the following.
How does diffraction change depending on the size of the gap and the wavelength? So I know that as the gap gets smaller, diffraction increases. But does this continue if the gap gets smaller than the wavelength? I want to know what happens if the gap becomes equal to or smaller than the wavelength (does diffraction still increase?)

Also can this be mathematically explained through the use of formulas from the HSC Syllabus?

Thanks!

 

[Drdusk]

If I was to explain this I would have to provide graphs which idk if I can on here. Instead use this link, it explains it quite well with the relevant equations and graphs.

https://phys.libretexts.org/Bookshelves/University_Physics/Book:_University_Physics_(OpenStax)/Map:_University_Physics_III_-_Optics_and_Modern_Physics_(OpenStax)/4:_Diffraction/4.3:_Double-Slit_Diffraction

There is a way of mathematically expressing it through formulas for intensity and what not as you can see on the link I provided.

 

[AhaExperience]

My guess is that the two slits would start to act like a single slit. Huygen's Principle - every point on a wave acts as a source of secondary wavelets - would apply here. And if the two secondary sources are too close together, then it acts like a single source. If you Google "single slit diffraction" you'll find that there is a similar equation to Young's Double Slit. BTW you can observe single slit diffraction by making a very small gap between your thumb and forefinger, and observing a light on the far side of the gap...