Interboard optical data distribution by Bessel beam shadowing

We describe the efficient conversion of light from a laser diode into a Bessel beam whose axial intensity varies almost uniformly with distance using only a holographic optical element. An interesting shadowing property of the Bessel beam is demonstrated where on blocking the intense central spot the propagating ring pattern acts to reform the central spot a short distance following the obstruction. This behaviour together with the long propagation range for the Bessel beam's central spot are considered for multiboard optical interconnects.