Demonstration experiments on nondiffracting beams generated by thermal light

Abstract

Nondiffracting (Bessel) beams are normally generated using fully coherent light (a laser). Yet their distinctive properties (nondiffraction and self-reconstruction) can be obtained using a common halogen lamp as the primary source. Other experiments, for example, the creation of periodic intensity modulations along the optical axis, require a source with a much narrower spectrum. We present demonstrations that show that thermal light is useful for explaining several properties of a Bessel-beam generator and may help students to understand some issues of modern coherence theory.