Assessing the impact of spatial coherence on the sinusoidal linear Fresnel zone plate's depth of focus.

This research examines, using both theory and experimentation, how a light beam's spatial coherence affects a sinusoidal linear Fresnel zone plate's depth of focus. We generate a one-dimensional partially coherent Gaussian Schell-model beam from a coherent laser beam through putting a rotating diffuser near to the common focal plane of two cylindrical lenses in a 2f-system. By adjusting the beam spot size on the diffuser, one may modify the coherence width of the produced beam.