IEVref: 731-01-14 ID: Language: en Status: Standard Term: degree of coherence Synonym1: Synonym2: Synonym3: Symbol: Definition: a measure of the extent to which radiation can be considered to be coherent NOTE 1 – The magnitude of the degree of coherence is equal to the visibility, V, of the fringes of a 2-beam interference experiment: $\text{V}=\frac{{S}_{\text{max}}-{S}_{\text{min}}}{{S}_{\text{max}}+{S}_{\text{min}}}$ where Smax is the irradiance at a maximum of the interference pattern, and Smin is the irradiance at a minimum. NOTE 2 – Optical radiation is considered highly coherent when the degree of coherence exceeds 0.88, partially coherent for values less than 0.88 and incoherent for values significantly less than 0.88. Publication date: 1991-10 Source: Replaces: Internal notes: 2016-02-01: Formatting of Smax and min corrected to italic Smax. JGO 2017-06-02: Cleanup - Remove Attached Image 731-01-14.gif CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: