Patent ID: 8531646

Claim:
A tunable liquid crystal device comprising: a cell including parallel spaced apart substrates defining a cell gap and an aperture; a liquid crystal material disposed in the cell gap, a director configuration of the liquid crystal material at least near the substrates having a generally vertical orientation further including a spatially varying in-plane component conforming to an in-plane spatial pattern; and a biasing arrangement including; electrodes disposed on or in the parallel spaced apart substrates, the electrodes on or in both substrates being segmented to form opposing electrode segment pairs across the cell gap with the electrode segment pairs distributed across the aperture of the cell, and a voltage source connected with the electrodes and configured to simultaneously apply the same potential difference across all the electrode segment pairs and a spatially varying in-plane potential across the electrode segments of the electrode on or in each substrate to generate an operational electrical potential across the cell gap having an in-plane electric field component with adjustable spatial variation across the aperture of the cell and a vertical electric field component that is constant across the aperture of the cell, the vertical electric field component of the operational electrical potential biasing the director configuration of the liquid crystal material into an in-plane orientation generally conforming to the in-plane spatial pattern with at least one dimension adjustable by adjustment of the in-plane electric field component of the operational electrical potential wherein the at least one adjustable dimension includes a period of the in-plane spatial pattern; wherein the cell gap and the liquid crystal material define a half-wave phase retardation across the cell gap for a selected wavelength of light that is steered.