the time over which propagating optical radiation may be considered to be coherent radiation
Note 1 – The coherence time is equal to coherence length divided by the phase velocity in a medium.
Note 2 – The coherence time is given approximately by λ02/c0.Δλ where λ0 is the central wavelength, Δλ is the spectral linewidth and c0 is the speed of light in vacuum. |