Interference and Diffraction

Diffraction produces a bright spot where Poisson believed there would be darkness.

What It Shows

Edge diffraction around a 1/8" diameter steel ball bearing results in a visible spot in the center of its shadow. In 1818 this result—to the chagrin of Siméon D...

Wave/particle duality observed in Young's double slit experiment with camera sensitive to individual photons.

What it shows:
In this demonstration we perform the double-slit interference experiment with extremely dim light and show that even when the light...

What it shows:

A point light source will produce seemingly sharp shadows which turn out to be not at all sharp when viewed under magnification. Narrow interference bands are seen within the shadow of a straight edge while more complicated shapes yield...

What it shows:  A room-size laser interferometer with audio signal output. A standing wave is produced whenever a wave is reflected back on itself. A resonant cavity requires a second reflection so that the twice reflected wave has the opportunity to be...

What it shows:

A device to measure distances to an accuracy of fractions of the wavelength of light, it also provided the critical experiment for the non-existence of the ether and for the constancy of the speed of light in all inertial frames.

How it...

What it shows

Waves reflecting from two surfaces can interfere constructively and destructively. In this case it is light waves that are being reflected from the front and rear surfaces of thin soap or oil films. The interference produces a pattern of...

What it shows:

Waves reflecting from two surfaces can interfere constructively and destructively. In this case it is light waves that are being reflected at glass/air and air/glass interfaces. The interference produces a concentric ring pattern of rainbow...

10 cm microwaves are used for the demonstration of travelling and standing waves, reflection, interference, refraction, diffraction, absorption, polarization, tunneling, and waveguides.

What it shows:

The following is a sequence of experiments that can...