At a glance determination of laser light polarization state

We report a simple technique for the visual determination of a laser light polarization state. The technique is based on a phenomenon occurring when laser light impinges on a particular photopolymerizable mixture sandwiched between two glass plates. After a brief irradiation, some polarization dependent patterns are observed far from the incidence spot. This effect is due to light scattered by the polymerized material and waveguided by the glass. A visual inspection of the characteristic patterns allows an immediate determination of the light polarization. This technique could be conveniently exploited for qualitative and/or quantitative polarimetry, as well as for designing polarization-driven devices.