Polarization independent phase modulator
AssigneeKoninklijke Philips Electronics N.V.
InventorRifat Hikmet
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Abstract
The present invention provides a polarization independent phase modulator for light comprising a layer of chiral liquid crystal mixture that has a low enough pitch to provide polarization independence of the effective refractive index for visible light. The liquid crystal mixture is controllable between a helix oriented ground state and a tilted state induced by the application of an electric field across the liquid crystal mixture layer. The liquid crystal mixture is preferably dispersed in a network material which ensures that the helix-oriented ground state is resumed when removing the electric field.
Claims16
A polarization independent phase modulator (100) for light, comprising:
- two transparent substrates (101, 107);
- and
- a layer (104) of chiral liquid crystal mixture, between said substrates;
- wherein said chiral liquid crystal mixture is oriented in a helix oriented ground state;
- is controllable between said ground state and a tilted state by means of an electric field;
- has an effective refractive index which depends on the state of said liquid crystal mixture;
- and
- has a pitch that is sufficiently small to make the value of the refractive index substantially independent of the polarization of the light.
Dependencies are inferred from the claim text.