Abstract: An EO phase shifter for modulating an electrical signal onto an optical wave is manufactured using CMOS process tools whereby a waveguide core made of EO material has intimate contacts with its electrodes. Specifically, the waveguide core is made of a Silicon-Rich Silicon Nitride (SRN) material which has a high linear refractive index n and a high third order nonlinear susceptibility. The electrodes are made of P or N doped silicon. Also, polarization of the optical wave is oriented normal to interfaces between the waveguide core and the electrodes. With this combination, the EO phase shifter exhibits high optical confinement, low propagation loss, and a high electro-optic overlap integral for modulation.
Type:
Grant
Filed:
October 24, 2019
Date of Patent:
January 19, 2021
Assignee:
VEO, INC.
Inventors:
Rajat Sharma, Chen-Kuo Sun, Robert B. Welstand
Abstract: In accordance with the present invention, an elongated phase shifting diode is provided for modulating an electrical signal onto an optical wave. Structurally, the phase shifting diode includes a p doped central stripe that extends through a phase shifting length L of a waveguide. P+ doped finger stripes and N+ doped finger stripes, which are laterally and axially offset from each other, extend into the waveguide for contact with the p doped central stripe along the length L. In combination, the plurality of N+ doped finger stripes and the p doped central stripe create a plurality of PN junctions that are structurally aligned along the p doped central stripe to establish electrically parallel phase shifting functions for the elongated diode.
Type:
Grant
Filed:
September 4, 2019
Date of Patent:
October 27, 2020
Assignee:
VEO, INC.
Inventors:
Robert B. Welstand, Chen-Kuo Sun, Rajat Sharma