Controllable optical waveguide
First Claim
1. A controllable optical waveguide, comprising:
- a core through which light can propagate;
cladding provided around the core, the cladding having an outer surface on a side thereof remote from the core and including a plurality of portions made of a material having a refractive index which varies in respones to an applied electric field; and
a plurality of first electrode pairs, each of the electrode pairs including two electrodes located adjacent the outer surface of the cladding and arranged to apply an electric field to a respective one of the portions of the cladding, each of the electrodes having a plurality of fingers, and the fingers of one of the electrodes of each said pair being interdigitated with the fingers of the other electrode of such pair;
wherein a respective electric potential can be applied to each said pair of electrodes and, as the electric potential at one of the pairs of electrodes is changed from a first value to a second value, the refractive index of the corresponding portion of the cladding changes from a first value at which light propagating through the core and impinging on such portion of the cladding is reflected back into the core to a second value at which light propagating through the core and impinging on such portion passes through such portion and thereby escapes from the waveguide.
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Accused Products
Abstract
A controllable optical waveguide includes a core through which light can propagate and cladding around the core, at least one of the core and cladding having plural portions made of a material having a refractive index which varies in response to an applied electric field. A plurality of electrode pairs are arranged so as to each be able to apply an electric field to a respective one of the portions of the material in a manner effecting a change in its refractive index. Each electrode pair includes two electrodes which each have a plurality of fingers, the fingers of one electrode of each pair being interdigitated with those of the other electrode of the pair. As the electric field produced by a given electrode pair varies, the refractive index of the corresponding portion of the material varies in a manner causing the waveguide to retain light or to allow light to escape through such portion.
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Citations
16 Claims
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1. A controllable optical waveguide, comprising:
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a core through which light can propagate; cladding provided around the core, the cladding having an outer surface on a side thereof remote from the core and including a plurality of portions made of a material having a refractive index which varies in respones to an applied electric field; and a plurality of first electrode pairs, each of the electrode pairs including two electrodes located adjacent the outer surface of the cladding and arranged to apply an electric field to a respective one of the portions of the cladding, each of the electrodes having a plurality of fingers, and the fingers of one of the electrodes of each said pair being interdigitated with the fingers of the other electrode of such pair; wherein a respective electric potential can be applied to each said pair of electrodes and, as the electric potential at one of the pairs of electrodes is changed from a first value to a second value, the refractive index of the corresponding portion of the cladding changes from a first value at which light propagating through the core and impinging on such portion of the cladding is reflected back into the core to a second value at which light propagating through the core and impinging on such portion passes through such portion and thereby escapes from the waveguide. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A display device, comprising:
a plurality of controllable optical waveguides arranged side by side, each said waveguide including;
a core through which light can propagate;
cladding provided around the core, the cladding having an outer surface on a side thereof remote from the core and including a plurality of portions made of a material having a refractive index which varies in response to an applied electric field; and
a plurality of first electrode pairs, each of the electrode pairs including two electrodes located adjacent the outer surface of the cladding and arranged to apply an electric field to a respective one of the portions of the cladding, each of the electrodes having a plurality of fingers, and the fingers of one of the electrodes of each said pair being interdigitated with the fingers of the other electrode of such pair;
wherein a respective electric potential can be applied to each said pair of electrodes and, as the electric potential at one of the pairs of electrodes is changed from a first value to a second value, the refractive index of the corresponding portion of the cladding changes from a first value at which light traveling through the core and impinging on such portion of the cladding is reflected back into the core to a second value at which light traveling through the core and impinging on such portion passes through such portion and thereby escapes from the waveguide; and
wherein each of the first electrode pairs is common to all of the waveguides and is arranged to simultaneously apply an electric field to the corresponding portion of the cladding of each of the waveguides; and
including means for directing light into each of the waveguides.- View Dependent Claims (15, 16)
Specification