Abstract: A phase only spatial light modulating device for variably changing the phase of light passing through the device without changing the polarization of the light. Two analog state ferroelectric liquid crystal phase only spatial light modulators are placed such that their smectic layers are orthogonal to each other. The angle of the molecules in the two modulators is controlled to be at the same angle. Whereby light passing through both of the modulators obtains a phase delay for arbitrary polarized input light without amplitude modulation or change in polarization state.

Abstract: A photosensitive element 46 absorbs at least a portion of an incident write beam 40, causing a spatially varying electric field to be applied across a layer of a ferroelectric liquid crystal (FLC) 48, thereby forming a pattern of local polarizations corresponding to the spatially varying electric field. In one embodiment, a signal beam is modulated with a phase variation characteristic of a particular aberrator. The signal beam is then combined with a substantially plane wave reference beam to form interference fringes. These interference fringes are directed as a write beam onto photosensitive layer 46, forming a hologram in FLC layer 48 which can be read optically. An incident beam of light can be diffracted by a hologram formed in the FLC layer, thereby modulating the incident beam of light with the phase variations comprising the hologram.