Optical information transfer based on helico-conical laser beams

We generated holographic masks starting with the interference between the reference beam and the signal beam, which is diffracted by the object. We investigate additive and multiplicative combinations between conical and helical phase distributions as compound objects to be inserted in the signal beam. We explored experimentally the dynamics of the diffracted intensity patterns, in two and three dimensions, after these holographic masks are addressed onto a programmable spatial light modulator. The diffracted intensity spatial arrangement contain information about constructive parameters used for holographic masks generation and exhibit asymmetric shapes and peaks along the optical axis in all analyzed compound objects. We introduce a reading mask in the optical path and, by analyzing changes of the spatial distribution in the final diffracted intensity arrangement, is possible to read the values of the constructive parameters. The generation of these reading masks in each case is discussed.