DECOLLIMATION

In a beam with the minimum possible ray divergence or convergence, any mechanism by which rays are caused to diverge or converge from parallelism. Note 1: Decollimation may be deliberate for systems reasons, or may be caused by many factors, such as refractive index inhomogeneities, occlusions, scattering , deflection , diffraction , reflection , and refraction . Note 2: Decollimation occurs in applications such as radio , radar , sonar , and optical communications .