title: Ray and van cittert-zernike characterization of spatial coherence.
abstract: We discuss a ray and a van Cittert-Zernike characterization of spatial coherence in condensers for projection systems. We present a rule of thumb with which to estimate the modulus of the coherence function at a given point of the illuminated object and a ray-tracing methodology with which to determine this modulus. For uniform illumination of the pupil we relate the modulus of the coherence function and the pupil-filling factor. We suggest that the rms of the angular ray spread at a given object point is an appropriate metric with which to characterize local coherence properties.
authors: J M
authors: JM
authors: Sasián
authors: S A
authors: SA
authors: Lerner
authors: T Y
authors: TY
authors: Lin
authors: L
authors: L
authors: Laughlin