Polarization-Independent LC Devices

Most of the LC devices operate under a linearly polarized light in order to achieve high contrast ratio. The use of a polarizer reduces the optical efficiency dramatically. The maximum transmittance of a pair of polarizers is only about 38%. Polarization-independent LC devices for phase or amplitude modulation are highly desirable. 

In the following sections, we introduce two polarization-independent LC phase modulators (1) a double-layered structure with two ultra-thin anisotropic polymer films as cell separators, and (2) a double-layered LC gel without any separator. 

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In this chapter, we only select four topics to illustrate the potential appUcations of liquid crystals in photonics and their technical challenges. The four representative subjects selected are (1) laser beam steering, (2) variable optical attenuator, (3) tunable-focus lens, and (4) polarization-independent LC devices. 

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