Method and system for a low-voltage integrated silicon high-speed modulator

A system for communication, the system comprising:

• an optical modulator comprising first and second optical waveguides and two optical phase shifters, wherein each of the two optical phase shifters comprises a p-n junction with a horizontal section and a vertical section, wherein in each of the two optical phase shifters, a first of a p-doped region and an n-doped region is in a slab waveguide portion and in a rib waveguide portion of the phase shifters and a second of the p-doped region and n-doped region is only in the slab waveguide portion, wherein in each of the two optical phase shifters, p+ and p++ regions and n+ and n++ regions extend above a top surface of the waveguide portion of the phase shifters such that the p++ and n++ regions are at a same height as a top of the rib waveguide portion, and wherein the optical modulator is operable to:
• receive an optical signal in the first optical waveguide,
• couple a portion of the optical signal from the first waveguide to the second optical waveguide;
• modulate a phase of at least one optical signal in the first and second waveguides utilizing the optical phase shifters;
• and
• couple a portion of the phase modulated optical signals between the first and second waveguides, thereby generating output signals into both output waveguides of the modulator.

A system for communication, the system comprising:

• an optical modulator in a silicon photonic transceiver, said optical modulator comprising:
• first and second optical waveguides;
• first and second optical phase shifters, each of the two optical phase shifters comprising a rib waveguide section on top of a slab waveguide section and a p-n junction with a horizontal section and a vertical section, wherein the horizontal section is formed by a portion of an n-doped layer formed on a p-doped layer where the p-doped layer is only in the slab waveguide section, and the vertical portion is formed by another portion of the n-doped layer that is in the same plane as the p-doped layer, and wherein in each of the first and second optical phase shifters, p+ and p++ regions and n+ and n++ regions extend above a top surface of the slab waveguide section of the phase shifters such that the p++ and n++ regions are at a same height as a top of the rib waveguide section, and wherein the optical modulator is operable to:
• receive an optical signal in the first optical waveguide,
• couple a portion of the optical signal from the first waveguide to the second optical waveguide;
• modulate a phase of at least one optical signal in the first and second waveguides utilizing the optical phase shifters;
• and
• couple a portion of the phase modulated optical signals between the first and second optical waveguides, thereby generating output signals into both output waveguides of the modulator.