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.