Abstract: A device includes two or more waveguide portions that are adjacent to each other, and each of the two or more waveguide portions includes a first n-doped semiconductor structure and a p-doped semiconductor structure in contact with the first n-doped semiconductor structure at a bottom surface and two lateral walls on opposite ends of the first n-doped semiconductor structure. The device includes an undoped semiconductor structure in contact with each of the p-doped semiconductor structures and free of contact with each of the first n-doped semiconductor structures, and the undoped semiconductor structure includes an optical waveguide core embedded within the undoped semiconductor structure. The device includes a second n-doped semiconductor structure in contact with the undoped semiconductor structure and free of contact with each of the first n-doped semiconductor structures and the p-doped semiconductor structures.

Abstract: A device includes two or more waveguide portions that are adjacent to each other, and each of the two or more waveguide portions includes a first n-doped semiconductor structure and a p-doped semiconductor structure in contact with the first n-doped semiconductor structure at a bottom surface and two lateral walls on opposite ends of the first n-doped semiconductor structure. The device includes an undoped semiconductor structure in contact with each of the p-doped semiconductor structures and free of contact with each of the first n-doped semiconductor structures, and the undoped semiconductor structure includes an optical waveguide core embedded within the undoped semiconductor structure. The device includes a second n-doped semiconductor structure in contact with the undoped semiconductor structure and free of contact with each of the first n-doped semiconductor structures and the p-doped semiconductor structures.

Abstract: A method includes obtaining a Photonic Integrated Circuit (PIC) with a butt-joint between a first core and a second core, wherein the butt-joint includes a poor quality region, wherein the first core is associated with a first optical device and the second core is associated with a second optical device, and wherein the first optical device and the second optical device are each on the PIC; etching away at least part of the poor quality region to form an etch trench between the first core and the second core; and growing an interconnect core between the first core and the second core in the etch trench.

Abstract: A Mach-Zehnder optical modulator with a travelling wave electrode having one or more signal transmission line conductors and one or more ground transmission line conductors is provided. The modulator includes a ground strip conductor extending substantially in parallel to the ground transmission line conductors, and a distributed bridging structure electrically connecting the ground strip conductor and at least one of the ground transmission line conductors along a substantial portion of a length thereof. The distributed bridging structure may be embodied by a plurality of electrical connections at disposed regularly spaced intervals.