Method and apparatus for phase-matched optical and RF wave propagations for semiconductor-based MZM modulators
AssigneeNeoPhotonics Corporation
InventorJianying Zhou
Life of this patent
Estimating the term…
Abstract
Optical modulators with semiconductor based optical waveguides interacting with an RF waveguide in a traveling wave structure. The semiconductor optical waveguide generally comprise a p-n junction along the waveguide. To reduce the phase walk-off between the optical signal and the RF signal, the traveling wave structure can comprise one or more compensation sections where the phase walk-off is reversed. The compensation sections can comprise a change in dopant concentrations, extra length for the optical waveguide and/or extra length for the RF waveguide. Corresponding methods are described.
Claims15
An optical modulator comprising:
- a silicon-based optical waveguide, and
- an RF waveguide;
- wherein the silicon-based optical waveguide and the RF waveguide are configured with one or more coupling regions to provide an RF electromagnetic field within the silicon-based optical waveguide and with one or more compensation sections with lengths of optical waveguide and/or RF waveguide that have substantially reduced or eliminated electro-optical coupling to reduce accumulated phase difference between an optical transmission in the silicon-based optical waveguide and an RF signal in the RF waveguide;
- and
- wherein the RF waveguide forms a continuous waveguide structure connecting adjacent coupling regions of each of the one or more compensation sections.
A method for modulating an optical signal comprising:
- propagating optical laser light down a silicon-based optical waveguide;
- and
- propagating RF signal along a RF waveguide;
- wherein the silicon-based optical waveguide and the RF waveguide are configured in a traveling wave modulator structure to provide electro-optical coupling, wherein the traveling wave modulator structure comprise one or more compensation sections at which relative phase of the propagating optical laser light and the propagating RF signal are corrected for a propagating speed differential and wherein the optical signal is modulated by a single RF signal.
Dependencies are inferred from the claim text.