Wu C S, Wu S T
Appl Opt. 1995 Nov 1;34(31):7221-7. doi: 10.1364/AO.34.007221.
Linear polarizers are generally employed in conjunction with advanced liquid-crystal filters for the protection of human eyes and optical sensors. For detection sensitivity under a no-threat condition to be maximized, the polarizer should remain in a clear state with a minimum insertion loss. When threats are present, it should be quickly switched to function as a linear polarizer with a high extinction ratio. Two types of switchable polarizer for sensor protection are demonstrated. The polarization conversion type exhibits a high optical efficiency in its clear state, a high extinction ratio in the linear polarizer state, and a fast switching speed, except that its field of view is limited to approximately ±10°. In contrast, an improved switchable dichroic polarizer functions effectively over a much wider field of view. However, its extinction ratio and optical efficiency in its clear state are lower than those of the polarization conversion type.
线性偏振器通常与先进的液晶滤光片配合使用，用于保护人眼和光学传感器。为了在无威胁条件下使检测灵敏度最大化，偏振器应保持清晰状态，插入损耗最小。当存在威胁时，它应迅速切换为具有高消光比的线性偏振器。展示了两种用于传感器保护的可切换偏振器。偏振转换型在其清晰状态下具有高光效率，在线性偏振器状态下具有高消光比，且切换速度快，只是其视场限制在大约±10°。相比之下，一种改进的可切换二向色性偏振器在更宽的视场上能有效发挥作用。然而，其在清晰状态下的消光比和光效率低于偏振转换型。
