US 5,239,598 A · Electro-optic waveguide device

Abstract

An electro-optic waveguide device (10) comprises an assembly of waveguides (30) connected to a common light input region (41) and forming a common far field diffraction pattern (44). The device (10) comprises an n.sup.+ GaAs substrate (14) bearing a waveguide lower cladding layer (16) of n.sup.+ Ga.sub.0.9 Al.sub.0.1 As, which is in turn surmounted by a waveguide core layer (18) of n.sup.- GaAs. The layer (18) has grooves (20) defining the waveguides (30), each of which has a respective Schottky contact (32). Each contact (32) is biased negative with respect to the substrate (14), which reverse biases the respective Schottky diode waveguide structure. The waveguide core layer (18) has electro-optic properties, and its refractive index varies with electric field. The phase of light emerging from each waveguide is therefore independently variable by means of its applied bias voltage. The waveguides (30) are arranged to provide output confined very largely to lowest order spatial modes, so that they produce a single far field diffraction pattern (44). Varying the set of bias voltages applied to the waveguides (30) produces output phase variation which changes the position of the diffraction pattern principal maximum (46) to produce beam steering.

Claims26

Dependent claims

An electro-optic waveguide device of multilayer construction including an array of electrically biasable waveguides of electro-refractive material, said device comprising:

(a) a waveguide core layer having a refractive index and two light confinement layers sandwiching said core layer therebetween, each of said confinement layers having a refractive index lower than said core layer refractive index, said waveguide core layer comprising at least part of a diode structure and said core layer depletable of charge carriers under a reverse bias applied by means of said confinement layers;
(b) means defining grooving at least partly through said waveguide core layer and for defining individual waveguides, said individual waveguides comprising said array;
(c) a grooving medium included in said waveguide array having a refractive index at least 1.5 less than said waveguide core layer refractive index, said means defining grooving and said medium comprising a means for optically isolating adjacent waveguides;
(d) a biasing means for each respective waveguide;
(e) means for inhibiting output of unwanted spatial modes from said waveguides;
and
(f) said waveguides and said biasing means comprising a means for providing for radiation output form said waveguides to interfere and for generating a far field diffraction pattern having a main lobe steerable across an output region of the device.

4 more elements

An electro-optic waveguide device of multilayer construction including an array of electrically biasable waveguides of electro-refractive material, said device comprising:

(a) a waveguide core layer having a refractive index and two light confinement layers sandwiching said core layer therebetween, each of said confinement layers having a refractive index lower than said core layer refractive index, said waveguide core layer comprising at least part of a diode structure and said core layer depletable of charge carriers under a reverse bias applied by means of said confinement layers;
(b) means defining grooving at least partly through said waveguide core layer and for defining individual waveguides, said individual waveguides comprising said array;
(c) a grooving medium included in said waveguide array having a refractive index at least 1.5 less than said waveguide core layer refractive index, said means defining grooving and said medium comprising a means for optical coupling between adjacent waveguides;
(d) means for inhibiting output of unwanted spatial modes from said waveguides;
and
(e) means for biasing said waveguides, said means for biasing said waveguides comprising respective bond pads and conductors connected thereto, said bond pads being located around a region of a device containing the waveguides and said conductors extending over a light input region of the device.

3 more elements

An electro-optic waveguide device of multilayer construction including an array of electrically biasable waveguides of electro-refractive material, said device comprising:

(a) a waveguide core layer having a refractive index and two light confinement layers sandwiching said core layer therebetween, each of said confinement layers having a refractive index lower than said core layer refractive index, said waveguide core layer comprising at least part of a diode structure and said core layer depletable of charge carriers under a reverse bias applied by means of said confinement layers;
(b) means defining grooving at least partly through said waveguide core layer and for defining individual electro-optic waveguides, said individual electro-optic waveguides comprising said array;
(c) a grooving medium included in said waveguide array having a refractive index at least 1.5 less than said waveguide core layer refractive index, said means defining grooving and said medium comprising a means for inhibiting optical coupling between adjacent electro-optic waveguides;
(d) means for inhibiting output of unwanted spatial modes from said waveguides;
and
(e) a common analog voltage input;
(f) a signal processing means for providing a digital output corresponding to analog input voltage;
(g) a detector array, connected to said signal processing means, said detector array comprising detectors disposed along a path traversed by an electro-optic waveguide array output in response to voltage input variation;
and
(h) the number of electro-optic waveguides is m, each of said waveguides includes a respective bias electrode, each bias electrodes having a length nL, where n=1 to m and denotes the nth waveguide and electrode, and L is the length of a first electrode, the electrodes are connected to said common analog voltage input, said electro-optic waveguides and said bias electrodes comprising a means for providing said electro-optic waveguide array output focused together at said detector array.

7 more elements

An electro-optic waveguide device of multilayer construction including an array of electrically biasable waveguides of electro-refractive material, said device comprising:

(a) an electro-absorbing waveguide core layer having a refractive index and two light confinement layers sandwiching said core layer therebetween, each of said confinement layers having a refractive index lower than said core layer refractive index, said waveguide core layer comprising at least part of a diode structure and said core layer depletable of charge carriers under a reverse bias applied by means of said confinement layers, wherein said waveguide core layer is comprised of an electro-absorbing material at a light source wavelength,;
(b) means defining grooving at least partly through said waveguide core layer and for defining individual electro-optic waveguides, said individual electro-optic waveguides comprising said array;
(c) a grooving medium included in said waveguide array having a refractive index at least 1.5 less than said waveguide core layer refractive index, said means defining grooving and said medium comprising a means for inhibiting optical coupling between adjacent electro-optic waveguides;
(d) means for inhibiting output of unwanted spatial modes from said waveguides;
(e) a light source means for providing light as an input to each of said waveguides, said light source means having a wavelength for which said waveguides are electro-absorbing;
(f) respective electrical biasing means associated with each of said waveguides, said biasing means being connected to a respective source of high and low voltages corresponding to a binary digit, and each said waveguide being switchable between opaque and transmitting states in response to voltage change of said associated biasing means,
(g) light intensity weighting means, associated with said waveguides for weighting light beams transmitted by said waveguides with intensities weighted in accordance with a binary doubling scheme, and
(h) detecting means for receiving and summing weighted output beam intensities from said waveguides and said weighting means, said detecting means including means for providing an analog output voltage corresponding to said sum.

5 more elements

Dependencies are inferred from the claim text.

Electro-optic waveguide device

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Electro-optic waveguide device

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Abstract

Claims26