Silicon optical modulator, method for making the same

An optical modulator comprising:

• a silicon-on-insulator substrate;
• and
• a first waveguide and a second waveguide arranged parallel to each other in the silicon-on-insulator substrate, the first waveguide comprising a first PN junction, the second waveguide comprising a second PN junction, at least one of the first PN junction and the second PN junction being disposed at an interface between a P type doped region and a N type doped region, the interface having an irregular shape that is not perpendicular to a plane in which the silicon-on-insulator substrate lies, the interface separating the P type doped region and the N type doped region being along an L-shaped line that is slanted relative to an axis perpendicular to the plane in which the silicon-on-insulator substrate lies.

An optical modulator comprising:

• a silicon-on-insulator substrate;
• and
• a first waveguide and a second waveguide arranged parallel to each other in the silicon-on-insulator substrate, the first waveguide comprising a first PN junction, the second waveguide comprising a second PN junction, at least one of the first PN junction and the second PN junction being disposed at an interface between a P type doped region and a N type doped region, the interface having an irregular shape that is not perpendicular to a plane in which the silicon-on-insulator substrate lies, the interface separating the P type doped region and the N type doped region being along a line that is slanted relative to an axis perpendicular to the plane in which the silicon-on-insulator substrate lies, each of the P type doped region and the N type doped region comprising a plurality of portions, each respective portion having a doping level that is different from at least one other portion of the same type.

An optical modulator comprising:

• a silicon-on-insulator substrate;
• and
• a first waveguide and a second waveguide arranged parallel to each other in the silicon-on-insulator substrate, the first waveguide comprising a first PN junction, the second waveguide comprising a second PN junction, at least one of the first PN junction and the second PN junction being disposed at an interface between a P type doped region and a N type doped region, the interface having an irregular shape that is not perpendicular to a plane in which the silicon-on-insulator substrate lies, the interface separating the P type doped region and the N type doped region being along a line that is slanted relative to an axis perpendicular to the plane in which the silicon-on-insulator substrate lies, the respective P type doped region and N type doped region comprising a plurality of portions having different depths and different doping levels compared to at least one other portion of the same type.

An optical modulator comprising:

• a silicon-on-insulator substrate;
• and
• a first waveguide and a second waveguide arranged parallel to each other in the silicon-on-insulator substrate, the first waveguide comprising a first PN junction, the second waveguide comprising a second PN junction, at least one of the first PN junction and the second PN junction being disposed at an interface between a P type doped region and a N type doped region, the interface having an irregular shape that is not perpendicular to a plane in which the silicon-on-insulator substrate lies, the interface separating the P type doped region and the N type doped region being along a line that is slanted relative to an axis perpendicular to the plane in which the silicon-on-insulator substrate lies, each P type doped region and each N type doped region comprising a plurality of portions with mutually different doping levels, and at least one of the portions in one of the P type doped region and the N type doped region overlapping with at least one of the portions in the other of the P type doped region and the N type doped region.