US Patent 8649081 Photochromic article having two at least partially crossed photochromic-dichroic layers

Photochromic-dichroic articles are provided, which include a substrate, a first photochromic-dichroic layer over the substrate, and a second photochromic-dichroic layer over the first photochromic-dichroic layer. The first photochromic-dichroic layer includes a first photochromic-dichroic compound that is laterally aligned within the first photochromic-dichroic layer, and which defines a first polarization axis of the first photochromic-dichroic layer. The second photochromic-dichroic layer includes a second photochromic-dichroic compound that is laterally aligned within the second photochromic-dichroic layer, and which defines a second polarization axis of the second photochromic-dichroic layer. The first polarization axis and the second polarization axis are oriented relative to each other at an angle of greater than 0° and less than or equal to 90°. The photochromic-dichroic articles can provide, for example, a combination of increased optical density and increased kinetics when exposed to a given amount of actinic radiation.