Interferometric visibility

Visibility is defined as the ratio of the amplitude of the interference pattern to the sum of the powers of the individual waves.

The pointwise definition may be expanded to a visibility function varying over time or space.

For example, the phase difference varies as a function of space in a two-slit experiment.

Alternately, the phase difference may be manually controlled by the operator, for example by adjusting a vernier knob in an interferometer.

If the two optical fields are ideally monochromatic (consist of only single wavelength) point sources of the same polarization, then the predicted visibility will be where

Photons, atoms, electrons, neutrons, and molecules have exhibited interference in double-slit interferometers.