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US 6,192,167 B1Granted
Differential drive optical modulator
AssigneeUniphase Telecommunications Products, Inc.
InventorsKarl Kissa, Gregory McBrien, Edward Wooten
Life of this patent
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Abstract
A differential input optical modulator, suited for an electrical driver with complementary outputs is provided by the present invention. One embodiment uses a X-cut LiNbO3 substrate, with or without a buffer layer, to reduce cost of manufacture in comparison to some known devices that employ a Z-cut LiNbO˜ substrate. These prior art devices require both buffer and charge bleed-off layers. The present invention also includes a quasi-symmetric electrode structure in which the applied fields run parallel to the surface of the substrate.
Claims28
An electro-optic modulator for use in an optical communication system having an optical signal transiting therethrough, the modulator comprising:
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- wherein said first input electrode is configured as a center electrode relative to said optical waveguide legs and said second input electrode is configured as an exterior electrode relative to said optical waveguide legs.
3 more elements
An electro-optic modulator for use in an optical communication system having an optical signal transiting therethrough, the modulator comprising:
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- a supplemental ground electrode formed on said upper substrate surface to balance electrical impedances for said first and second input electrodes.
3 more elements
An electro-optic modulator for use in an optical communication system having an optical signal transiting therethrough, the modulator comprising:
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- wherein said input electrodes are configured serially along said optical waveguide first and second legs.
3 more elements
An electro-optic modulation apparatus for modulating an optical signal transiting through an optical communication system, the apparatus comprising:
- an optical modulator having
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- an interface structure for receiving modulation signals for modulation the optical beam, said interface structure configured to be in electrical communication with said optical modulator first and second input electrodes;
- and
- wherein said first input electrode is configured as a center electrode relative to said optical waveguide legs and said second input electrode is configured as an exterior electrode relative to said optical waveguide legs.
5 more elements
An electro-optic modulation apparatus for modulating an optical signal transiting through an optical communication system, the apparatus comprising:
- an optical modulator having
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- an interface structure for receiving modulation signals for modulation the optical beam, said interface structure configured to be in electrical communication with said optical modulator first and second input electrodes;
- and
- wherein said interface structure further comprises a means for adjusting electrical impedance values for the apparatus.
6 more elements
An electro-optic modulation apparatus for modulating an optical signal transiting through an optical communication system, the apparatus comprising:
- an optical modulator having
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- an interface structure for receiving modulation signals for modulation of the optical beam, said interface structure configured to be in electrical communication with said optical modulator first and second input electrodes, said interface structure further comprising a stripline, and wherein said interface structure stripline further comprises a Y shaped conductor.
3 more elements
An electro-optic modulator for use in an optical communication system having an optical signal transiting therethrough, the modulator comprising:
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- a means for minimizing extraneous ground current outside of said ground electrodes.
3 more elements
An electro-optic modulation apparatus for modulating an optical signal transiting through an optical communication system, the apparatus comprising:
- an optical modulator having
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- an interface structure for receiving modulation signals for modulation of the optical beam, said interface structure configured to be in electrical communication with said optical modulator first and second input electrodes;
- and
- a means for providing a cascade launch of said modulation signal.
7 more elements
An electro-optic modulator for use in an optical communication system having an optical signal transiting therethrough, the modulator comprising:
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- a phase reversal region wherein minor portions of said input and ground electrodes are symmetrically displaced laterally from major portions thereof along said substrate upper surface so as to maintain electrode impedance.
3 more elements
An electro-optic modulator for use in an optical communication system having an optical signal transiting therethrough, the modulator comprising:
- an electro-optic substrate having an electro-optic axis oriented parallel to an upper surface of the substrate;
- an optical waveguide adapted to receive the optical signal and formed in the upper surface of said substrate, said optical waveguide having first and second legs spaced from one another;
- first and second input electrodes formed on said substrate upper surface and adapted to receive a modulation signal, with each of said input electrodes configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- first and second ground electrodes formed on said substrate upper surface spaced from a respective one of said input electrodes and configured to be in electro-optic communication with a corresponding one of said optical waveguide legs but substantially misregistered therewith;
- and
- a means for maintaining said ground electrodes at the same voltage.
3 more elements
Dependencies are inferred from the claim text.