Recent content by Dan Forth

Hey Doc cheers for the reply. Yeah I've been looking through the textbooks (Fresnel diffraction rather than Fraunhoffer I think) but it's not as simple as I'd hoped. The Bessel functions from the standard analysis will never give you the dot disappearing, as the analysis is invalid for x...

Hi hoping someone can help me with this problem. If I block plane monochromatic light (wavelength lambda) with a circular disc of radius r, and then look at the diffraction pattern on a screen placed a distance x behind the disc, I get a bright spot in the centre of the shadow. All well and...