Differential optical waveguide modulator
AssigneeNokia Solutions and Networks Oy
InventorsAlessandro Aimone, Philipp Thomas
Life of this patent
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Abstract
A planar electro-optic Mach-Zehnder modulator (MZM) includes two optical waveguide arms and three drive electrodes extending along the optical waveguide arms to modulate light propagating therein. A middle one of the drive electrodes is between the two optical waveguide arms, and the two optical waveguide arms are between outer ones of the drive electrodes. An electrical drive circuit is connected to provide first modulation signals to the two outer ones of the drive electrodes and a second modulation signal to the middle one of the drive electrodes, wherein the second modulation signal is voltage-inverted relative to the first modulation signals.
Claims10
An apparatus comprising:
- a planar electro-optic Mach-Zehnder modulator (MZM) disposed along a surface of a substrate and comprising:
- two optical waveguide arms extending along the surface and optically connected to receive light in parallel from an optical splitter;
- three drive electrodes extending along the optical waveguide arms to modulate light propagating therein, a middle one of the three drive electrodes being between the two optical waveguide arms, the two optical waveguide arms being between two outer ones of the three drive electrodes;
- and
- an electrical drive circuit connected to provide first modulation signals to the two outer ones of the three drive electrodes and a second modulation signal to the middle one of the three drive electrodes, wherein the second modulation signal is voltage-inverted relative to the first modulation signals;
- and
- wherein the electrical drive circuit comprises an electrical signal splitter in a signal path of the second modulation signal to the middle one of the three drive electrodes.
A method comprising:
- applying first radio-frequency (RF) electrical drive signals to two outer drive electrodes of a planar electro-optic Mach-Zehnder modulator;
- and,
- applying a second RF electrical drive signal to a middle drive electrode of the planar electro-optic Mach-Zehnder modulator, the second RF electrical drive signal being voltage-inverted relative to the first RF electrical drive signals;
- wherein the middle drive electrode is between and along two optical waveguide arms of the planar electro-optic Mach-Zehnder modulator and the two optical waveguide arms are between and along the outer drive electrodes;
- and
- wherein the method further comprises splitting a first single-ended component of a differential drive signal to produce the first drive signals and splitting the second RF drive signal to direct the second RF drive signal to the middle drive electrode along two different paths.
An apparatus comprising:
- a planar electro-optic Mach-Zehnder modulator (MZM) disposed along a surface of a substrate and comprising:
- two optical waveguide arms extending along the surface and optically connected to receive light in parallel from an optical splitter;
- three drive electrodes extending along the optical waveguide arms to modulate light propagating therein, a middle one of the three drive electrodes being between the two optical waveguide arms, the two optical waveguide arms being between two outer ones of the three drive electrodes;
- and
- an electrical drive circuit connected to provide first modulation signals to the two outer ones of the drive electrodes and a second modulation signal to the middle one of the drive electrodes, wherein the second modulation signal is voltage-inverted relative to the first modulation signals;
- and
- wherein the electrical drive circuit comprises a first electrical signal splitter for electrically coupling a first differential output port of a differential driver to the two outer ones of the drive electrodes, and a second electrical signal splitter in a signal path between a second differential output port of the differential driver and the middle one of the drive electrodes.
Dependencies are inferred from the claim text.