Electrode structures for optical modulators

A device comprising:

• a substrate;
• an optical waveguide formed in or on the substrate;
• a signal electrode extending along a longitudinal axis, comprising:
• a first signal portion comprising a first end proximate to the optical waveguide to induce a signal from the signal electrode to the optical waveguide, and a second end distal from the optical waveguide, and
• a second signal portion at least partially connected to the second end of the first signal portion;
• and
• a ground electrode comprising:
• first ground portions adjacent to the substrate and on opposite lateral sides of the first signal portion, and
• second ground portions, including a first portion and a second portion,
• the first signal portion extending through a gap between the first portion and the second portion, and
• the second signal portion overlapping a portion of a length of the first portion and a portion of a length of the second portion, and
• the ground electrode forming an enclosure that encloses the signal electrode with regard to the substrate.

A device comprising:

• a substrate;
• an optical waveguide formed on or in the substrate;
• and
• an electrode structure on the substrate extending along a longitudinal axis, the electrode structure comprising:
• an enclosure comprising a ground electrode and a signal electrode,
• the ground electrode comprising:
• an interior member, including a first portion and a second portion, dividing the enclosure into a first space and a second space,
• the interior member including one or more gaps connecting the first space to the second space, and
• a gap, of the one or more gaps, separating the first portion from the second portion, and
• the signal electrode comprising a first signal portion and a second signal portion,
• the first signal portion extending from the first space through at least one of the one or more gaps into the second space, and
• at least part of the first signal portion being proximate to the optical waveguide to induce a signal from the signal electrode to the optical waveguide, and
• the second signal portion in the second space being connected to the first signal portion to reduce radio frequency loss associated with the electrode structure,
• the second signal portion overlapping a portion of a length of the first portion and a portion of a length of the second portion, and
• the signal electrode being enclosed, with regard to a surface of the substrate, by the enclosure in a plane perpendicular to the longitudinal axis.