A silicon optical modulator is fabricated to have a multi-slab structure between the contacts and the waveguide, imparting desirable performance attributes. A first slab comprises dopant of a first level. A second slab adjacent to (e.g., on top of) the first slab, comprises a doped region proximate to a contact, and an intrinsic region proximate to the waveguide. The parallel resistance properties and low overlap between the highly doped silicon and optical mode pigtail afforded by the multi-slab configuration, allow the modulator to operate with reduced optical losses and at a high speed. Embodiments may be implemented in a Mach-Zehnder interferometer or in micro-ring resonator modulator configuration.

An optoelectronic device includes a silicon substrate, with a silicon waveguide layer disposed over the silicon substrate and including an optical waveguide. One or more through-silicon vias (TSVs) extend through the silicon substrate and contact the silicon waveguide layer. A III-V base layer is disposed over the silicon waveguide layer, and an optical amplifier is disposed on the III-V base layer and optically coupled to the optical waveguide.

An electro-optical modulator assembly including a transistor including a gate, a drain, and a source disposed on a substrate, a photonic modulator including a first waveguide structure positioned between a first electrode and a second electrode, the photonic modulator being integrated with the transistor on the substrate, and a metal connection coupled between the drain of the transistor and one of the first and second electrodes of the photonic modulator.

An optical modulating device may include a plurality of quantum dot (QD)-containing layers having QDs and a plurality of refractive index change layers. The QD-containing layers may be disposed between the refractive index change layers, respectively. The optical modulating device may be configured to modulate light-emission characteristics of the plurality of QD-containing layers. At least two of the QD-containing layers may have different central emission wavelengths. At least two of the plurality of refractive index change layers may include different materials or have different carrier densities.

A novel phase shifter design for carrier depletion based silicon modulators, based on an experimentally validated model, is described. It is believed that the heretofore neglected effect of incomplete ionization will have a significant impact on ultra-responsive phase shifters. A low VL product of 0.3 V.Math.cm associated with a low propagation loss of 20 dB/cm is expected to be observed. The phase shifter is based on overlapping implantation steps, where the doses and energies are carefully chosen to utilize counter-doping to produce an S-shaped junction. This junction has a particularly attractive VL figure of merit, while simultaneously achieving attractively low capacitance and optical loss. This improvement will enable significantly smaller Mach-Zehnder modulators to be constructed that nonetheless would have low drive voltages, with substantial decreases in insertion loss. The described fabrication process is of minimal complexity; in particular, no high-resolution lithographic step is required.

Provided is an optical modulator which is small in optical loss, is small in a size, and is low in required voltage and is operable to perform high-speed operation. The optical phase modulator 100 comprises a rib-type waveguide structure 110 including: a PN junction 106 which is formed of Si and is formed in a lateral direction on a substrate; and an Si.sub.1-xGe.sub.x layer 108 which is constituted of at least one layer and is doped with an impurity to a p-type and is superposed on the PN junction 106 so as to be electrically connected to the PN junction 106. The rib-type waveguide structure 110 has a substantially uniform structure along a light propagation direction, and in a direction parallel with the substrate and perpendicular to the light propagation direction, a position of a junction interface 106a of the PN junction 106 is offset from a center of the Si.sub.1-xGe.sub.x layer 108.

A silicon optical modulator is fabricated to have a multi-slab structure between the contacts and the waveguide, imparting desirable performance attributes. A first slab comprises dopant of a first level. A second slab adjacent to (e.g., on top of) the first slab, comprises a doped region proximate to a contact, and an intrinsic region proximate to the waveguide. The parallel resistance properties and low overlap between the highly doped silicon and optical mode pigtail afforded by the multi-slab configuration, allow the modulator to operate with reduced optical losses and at a high speed. Embodiments may be implemented in a Mach-Zehnder interferometer or in micro-ring resonator modulator configuration.

An optical modulator includes multiple segments including modulator segments and a Radio Frequency (RF) crossing segment where RF lines extending a length of the modulator cross one another. The present disclosure includes optimization of one or more of a geometry of the RF crossing and a location of the RF crossing segment along the length. The geometry is selected so that the RF crossing segment appears as another segment having similar characteristics as modulator segments. The location of the RF crossing segment is selected to balance out fabrication error and phase efficiency.

An optical modulator includes a first arm and a second arm, each arm includes an arrangement with an equal amount of p-doped material and an equal amount of n-doped material, such that mask misalignment causes a same effect in both arms; and each arm includes a plurality of segments where electrodes connect for push-pull operation of the first arm and the second arm.

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.sup.+ doped finger stripes and N.sup.+ 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.sup.+ 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.