Coherence is a property of waves that measures the ability of the waves to interfere with each other.
Coherence physics - Explanation.
Two waves that are coherent can be combined to produce an unmoving distribution of constructive and destructive interference (a visible interference pattern) depending on the relative phase of the waves at their meeting point. When combined, waves that are incoherent produce rapidly moving areas of constructive and destructive interference and therefore ...
Waves also have the related property of spatial coherence; this is the ability of any one spatial position of the wavefront to interfere with any other spatial position. Young's double-slit experiment relies on spatial coherence of the beam illuminating the two slits; if the beam was spatially incoherent—i.e. if the sunlight was not first passed through a single slit—then no interference pattern would be seen.
Spatial coherence is high for spherical waves and plane waves as it is related to the wavelength, size and coherenc ...
A wave can also be coherent with itself, a property known as temporal coherence. If a wave is combined with a delayed copy of itself (as in a Michelson interferometer), the duration of the delay over which it produces visible interference is known as the coherence time of the wave, Δtc. From this, a corresponding coherence length can be calculated:
