Modulator with signal electrode enclosed by ground electrode

A device, comprising:

• a substrate;
• one or more waveguides formed upon or formed in the substrate;
• a signal electrode including an outer surface;
• and
• a ground electrode including an inner surface that is radially spaced from the outer surface of the signal electrode,
• a gap length between the inner surface and the outer surface being substantially constant in each radial direction from the signal electrode, and
• the ground electrode at least partially overlapping a portion of a width of the signal electrode.

A device, comprising:

• a substrate;
• one or more waveguides formed upon or formed in the substrate;
• a signal electrode including an outer surface;
• and
• a ground electrode including an inner surface,
• the ground electrode at least partially overlapping a portion of a width of the signal electrode and extending above the signal electrode in a direction perpendicular to the width of the signal electrode and along a length of the signal electrode, and
• the inner surface comprising a plurality of surfaces that form a curved inner surface.