Waveguided electrooptic switches using ferroelectric liquid crystals
First Claim
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1. An electro-optic switch comprising:
- (a) coplanar light transmissive optical channel waveguide core portions for supporting guided modes of light polarized substantially parallel to the plane of the waveguide core portions, said waveguide core portions having a longitudinal light propagation axis and a core refractive index within a first range;
(b) a cladding layer having an initial ordinary index of refraction overlying a waveguide core portion and evanescently optically coupled thereto and comprising a substantially uniformly ordered layer of ferroelectric liquid crystal (FLC) having a cladding index of refraction which increases from said initial index of refraction in response to a change in voltage applied thereto, causing said cladding index to assume an index within a second range, lower than the first range of the refractive core index of said waveguides and not overlapping said first range; and
(c) voltage supply means for impressing a voltage across said cladding layer of a magnitude to cause the cladding index of said cladding layer to be increased to a sufficient extent to change the effective index of refraction of the guided modes within said core portion.
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Abstract
A tiny, high speed, low cost electrooptic switch is provided having co-planar waveguides of silicon oxynitride and a ferro-electric liquid crystal layer overlying the waveguides. A voltage source causes the molecular optic axis of the liquid crystal to rotate 45-90 degrees within the plane of the liquid crystal layer to cause a change of state of the switch.
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15 Claims
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1. An electro-optic switch comprising:
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(a) coplanar light transmissive optical channel waveguide core portions for supporting guided modes of light polarized substantially parallel to the plane of the waveguide core portions, said waveguide core portions having a longitudinal light propagation axis and a core refractive index within a first range; (b) a cladding layer having an initial ordinary index of refraction overlying a waveguide core portion and evanescently optically coupled thereto and comprising a substantially uniformly ordered layer of ferroelectric liquid crystal (FLC) having a cladding index of refraction which increases from said initial index of refraction in response to a change in voltage applied thereto, causing said cladding index to assume an index within a second range, lower than the first range of the refractive core index of said waveguides and not overlapping said first range; and (c) voltage supply means for impressing a voltage across said cladding layer of a magnitude to cause the cladding index of said cladding layer to be increased to a sufficient extent to change the effective index of refraction of the guided modes within said core portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification