# Airy Disc

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Published 2023-08-23

# (Supplementary) Airy Disc

Airy Discs are formed when light passes through an aperture. A disc-like pattern will be observed, and when two discs are too close to each other, the two light sources will not be discerenable from each other.

Take a look at this Airy Disc.

An airy disc can be seen, as well as concentric circles around it.

If we introduce a second source of light, we can see how the discs interact.

Now with a second source, we can clearly see two sets of rings.

Bring them close together, and we're slowly losing the ability to discern them.

Now that they are right next to each other, we aren't sure if they are two different light sources.

We can also use ImageJ to find out the intensity of the image across the slice.

Here's a single source.

And two sources, near to each other! We can't see the difference in peaks!

Open the aperture a little more, and we are able to see the two different pictures!

This relationship can be described by the Rayleigh Criterion:

\theta_min = 1.22 \frac{\lambda}{D}