US Patent 7256921 Polarizing, photochromic devices and methods of making the same

Various embodiments disclosed herein relate to optical elements comprising an at least partial coating having a first state and a second state connected to at least a portion of a substrate, the at least partial coating being adapted to switch from the first state to the second state in response to at least actinic radiation, to revert back to the first state in response to thermal energy, and to linearly polarize at least transmitted radiation in at least one of the first state and the second state. Other embodiments relate to optical elements comprising a substrate and at least one at least partially aligned photochromic-dichroic compound connected to at least a portion of the substrate and having an average absorption ratio greater than 2.3 in the activated state as determined according to CELL METHOD. Still other embodiments relate to security devices, liquid crystal cells and methods of making the same.