Partially Coherent Light
When discussing the theory of interference and diffraction of waves, one usually assumes that the fields remain perfectly sinusoidal for all values of time. This is obviously an idealized situation and we know that the radiation from an ordinary light source consists of finite* size wave trains, a typical time variation of which is shown in Fig. 5.1. As can be seen from the figure, the electric fields at times t and t + Δt will have a definite phase relationship if Δt ⪡ τC and will (almost) never have any phase relationship for Δt ⪢ τC, where τC represents the average duration of the wave trains (see Fig. 5.1).
KeywordsInterference Fringe Temporal Coherence Angular Diameter Complex Degree Partially Coherent
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