Liquid crystal polarization rotator and method of using same
First Claim
1. An apparatus, comprising:
- a wave plate having oppositely positioned first and second faces forming a cavity;
a nematic liquid crystal material being disposed between said oppositely positioned cavity faces; and
a first plurality of electrodes located relative to at least said first face of said cavity, wherein said first plurality of electrodes is configured to apply an electric field having a first component parallel to said first face, said first plurality of electrodes being able to rotate an orientation of said first electric field component and, hence, molecules of said liquid crystal material, by a plurality of angles.
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Accused Products
Abstract
A liquid crystal polarization rotator device is able to rotate polarization fast enough to compensate polarization mode dispersion. The amount or degree of rotation is rapidly reconfigurable. The device includes a cavity filled with a nematic liquid crystal material. The cavity has electrodes on a first face, e.g., a first substrate, and electrodes on a second face, e.g., a second substrate, opposite the first face. The electrodes are shaped and positioned to produce an electric field across the cavity capable of rotating the alignment direction of the molecules of the liquid crystal material in the cavity. The electrodes are patterned on the ends of optical fibers. Aligning and positioning of the electrodes on the ends of the optical fibers with a predetermined spacing forms the cavity that is filled with the nematic liquid crystal material. The filled cavity is a so-called liquid crystal microcell wave plate. A control system is used to control the “rapid” rotation of the alignment direction of the molecules of the liquid crystal material. The control system receives data regarding the polarization of light entering or leaving the microcell and adjusts the direction of the electric field also using trigger pulses such as to rotate the nematic liquid crystal material molecules by a first predetermined number of degrees greater than a second desired number of degrees of rotation. Then, the trigger pulses for the electric field are stopped after the molecules have rotated by the second desired number of degrees. In this manner, the molecules rotate by the second desired number of degrees much faster than if a pulse had been applied with the same speed to rotate them by the second desired number of degrees in he first place.
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Citations
20 Claims
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1. An apparatus, comprising:
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a wave plate having oppositely positioned first and second faces forming a cavity;
a nematic liquid crystal material being disposed between said oppositely positioned cavity faces; and
a first plurality of electrodes located relative to at least said first face of said cavity, wherein said first plurality of electrodes is configured to apply an electric field having a first component parallel to said first face, said first plurality of electrodes being able to rotate an orientation of said first electric field component and, hence, molecules of said liquid crystal material, by a plurality of angles. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus, comprising:
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first and second segments of an optical fiber;
at last one wave plate having oppositely positioned first and second faces forming a cavity, said first optical fiber segment having a front face adjacent to a central region of said first cavity face, and said second optical fiber segment having a front face adjacent to a central region of said second cavity face;
a nematic liquid crystal material being disposed between said oppositely positioned cavity faces; and
a first plurality of electrodes located relative to at least said first face of said cavity, wherein said first plurality of electrodes is configured to apply an electric field parallel to said first face, said first plurality of electrodes being able to rotate an orientation of said electric field and, hence, molecules of said liquid crystal material, by a plurality of angles. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A method for use in an apparatus for controllably rotating a state of polarization including,
first and second segments of an optical fiber, a wave plate having oppositely positioned first and second faces forming a cavity said first optical fiber segment having a front face adjacent to a central region of said first cavity face, and said second optical fiber segment having a front face adjacent to a central region of said second cavity face, a nematic liquid crystal material being disposed between said oppositely positioned cavity faces, and a first plurality of electrodes located relative to at least said first face of said cavity, wherein said first plurality of electrodes is configured to apply an electric field having a first component parallel to said first face; -
the method comprising;
generating an electric potential;
applying said electric potential to said first plurality of electrodes to generate an electric field parallel to said first face, said first plurality of electrodes being able to rotate an orientation of said electric field and, hence, molecules of said liquid crystal material, by a plurality of angles. - View Dependent Claims (20)
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Specification