Electrically tunable polarization imaging through configurating a single layer of infrared twisted nematic...

An infrared (IR) polarization imaging approach basically through configuring a polarized liquid-crystal (LC) component adjusted electrically before a common IR camera, is proposed. An experimental module composed of a single layer of the IR twisted nematic LC (IR-TNLC) structure for continuously or leapingly varying the polarized orientation of the imaging beams, has been characterized, which demonstrates an ideal polarization modulating behavior in three IR atmospherical windows. The typical polarized measurements in both the mid-wave infrared (MWIR) and the long-wave infrared (LWIR) regions indicate a perfect imaging efficiency mainly in the electronic target acquisition and the detailed feature recognition. According to common Stokes vectors and further, the DoLP and E-DoLP imaging mode, an electrically tunable re-orientation of the imaging beams, which is obviously different from the traditional polarized imaging only based on constructing several polarized states such as in a typical set of {0°, ± 45°, 90°}, can be performed effectively. The proposed method already presents some merits including a capacity of continuously scanning or leapingly shifting the polarized state in a range of {∼3.11°, 80.20°}/SWIR (shortwave infrared) or {0.08°, 89.15°}/ MWIR or {∼0.77°, 84.10°}/ LWIR, a higher imaging contrast, a remarkable reduction of the local glaring, almost completely eliminated ghosting, an obvious enhancement of the local pattern contour or some featured edges.