MOSCAP ring resonator optical modulator

A ring resonator optical modulator, comprising:

• a ring-shaped optical region in which optical radiation can propagate in a circular path, the optical region having an inner radius and an outer radius, the outer radius being coincident with an outer perimeter of the ring resonator optical modulator;
• a ring-shaped metal-oxide-semiconductor (MOS) capacitor structure having an upper gate layer of the MOS capacitor structure and a lower body layer of the MOS capacitor structure;
• an insulating material being disposed between the upper gate layer of the MOS capacitor structure and the lower body layer of the MOS capacitor structure;
• and a cladding region comprising cladding material of lower refractive index than the refracting index of the upper gate device layer or the lower body device layer disposed radially outwardly from the outer perimeter of the ring-shaped optical region;
• the optical radiation being radially confined at the outer perimeter of the ring-shaped optical region within the optical region due to refractive index contrast between the ring-shaped optical region and the cladding material;
• and
• a first electrode electrically coupled to the upper gate layer of the MOS capacitor structure and a second electrode electrically coupled to the lower body layer of the MOS capacitor structure, the first and second electrodes being radially disposed radially inwardly from the inner radius of the optical region.

A resonant electro-optic modulator comprising:

• a closed-loop optical resonator supporting a guided-wave mode of confined optical radiation, the optical radiation mode's guidance being provided in a cross-section of the closed-loop optical resonator by refractive index confinement, the cross-section having a radially inward and a radially outward side with respect to the closed-loop optical resonator structure;
• the optical resonator including a first semiconducting material device layer having a first radially outward boundary and a second semiconducting material device layer having a second radially outward boundary, the first and second semiconducting material device layers each being doped to conduct electric charge carriers, and separated by an insulating material to form a metal-oxide-semiconductor (MOS) structure;
• the insulating material comprising a first region having a first thickness and a second region having a second thickness larger than the first thickness and disposed adjacent the first region forming a boundary between the first and second regions of the insulating material;
• wherein the first region of insulating material is disposed against the first radially outward boundary along the circumference of the structure, and the second region of insulating material is disposed radially inward from, and abutting, the first region of insulating material, such that the guided-wave mode of optical radiation is confined by refractive index confinement between the first and/or second radially outward boundary on the radially outward side of the mode of optical radiation, and the boundary between the first and second regions of the insulating material on the radially inner side of the mode of optical radiation;
• the closed-loop optical resonator further having a first conducting electrode electrically connected to the first semiconducting material device layer, and a second conducting electrode electrically connected to the second semiconducting material device layer, such that application of a voltage across the first and second electrodes effects motion of charge into and/or out of the capacitor formed by the first semiconducting device layer, the first region of insulating material and the second semiconducting layer, and changes the effective refractive index seen by the mode of optical radiation.