Velocity matching electrode structure for electro-optic modulators

An electro-optic modulator comprising:

• an electro-optic substrate;
• at least one optical waveguide defined within the substrate having an optical signal propagating at an optical velocity;
• an electrode structure having a transmission line and conductive legs, the conductive legs extending the transmission line from the substrate, the transmission line having a signal electrode and at least one ground electrode;
• an electrical signal propagating at an electrical velocity along the transmission line, the electrical velocity substantially matching the optical velocity;
• and
• a dielectric layer disposed adjacent the signal electrode and the ground electrode, the dielectric layer having a dielectric constant lower than the substrate.

An electro-optic modulator comprising:

• an electro-optic substrate;
• at least one optical waveguide defined within the substrate having an optical signal propagating at an optical velocity;
• an electrode structure having a transmission line and conductive legs, the transmission line having a signal electrode and at least one ground electrode, the conductive legs extending the signal electrode from the substrate, the ground electrode being disposed directly over a surface of the substrate;
• an electrical signal propagating at an electrical velocity along the transmission line, the electrical velocity substantially matching the optical velocity;
• and
• a dielectric layer disposed adjacent the signal electrode, the dielectric layer having a dielectric constant lower than the substrate.

An electro-optic modulator comprising:

• an electro-optic substrate;
• at least one optical waveguide defined within the substrate having an optical signal propagating at an optical velocity;
• an electrode structure having an microstrip transmission line and conductive legs, the microstrip transmission line having a signal electrode and a ground electrode, the signal electrode having arms extending substantially perpendicular from the signal electrode, the conductive legs extending from the arms of the signal electrode to a surface of the substrate toward the waveguide, the ground electrode being disposed directly over a surface of the substrate;
• and
• an electrical signal propagating at an electrical velocity along the transmission line, the electrical velocity substantially matching the optical velocity.