Abstract: A phase modulation waveguide structure includes one of a semiconductor and a semiconductor-on-insulator substrate, a doped semiconductor layer formed over the one of a semiconductor and a semiconductor-on-insulator substrate, the doped semiconductor portion including a waveguide rib protruding from a surface thereof not in contact with the one of a semiconductor and a semiconductor-on-insulator substrate, and an electrical contact on top of the waveguide rib. The electrical contact is formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the waveguide rib and the electrical contact and lower than the optical refractive index of the doped semiconductor layer. During propagation of an optical mode within the waveguide structure, the electrical contact isolates the optical mode between the doped semiconductor layer and a metal electrode contact on top of the electrical contact.

Abstract: A system for optical data communication, including: a first sending node including a first data item for transmission to a first receiving node during a first timeslot; a second sending node including a second data item for transmission during a second timeslot; a first optical data link (ODL) and a second ODL; a first output switch configured to switch the first data item from the first sending node onto the first ODL during the first timeslot; a second output switch configured to switch the second data item from the second sending node onto the first ODL during the second timeslot; an optical coupler connecting the first and second ODL; and a first input switch operatively connecting the first receiving node with the second ODL and configured to switch the first data item from the second ODL to the first receiving node during the first timeslot.

Abstract: A system including first and second sending nodes, a horizontal optical data link (ODL) having optical signals propagating in opposite directions in first and second waveguide segments, a vertical ODL having optical signals propagating in the same direction throughout third and fourth waveguide segments, a first optical output switch operatively connecting the first sending node and the first waveguide segment and configured to switch first data item onto the first waveguide segment during a first timeslot, a second optical output switch operatively connecting the second sending node and the second waveguide segment and configured to switch second data item onto the second waveguide segment during a second timeslot, and an optical coupler pair operatively connecting the first and second waveguide segments to the third and fourth waveguide segments, respectively, and redirecting the first and the second data items from the horizontal to the vertical ODL.

Abstract: A method for arbitration including selecting, for an arbitration interval corresponding to a timeslot, a sending node from a plurality of sending nodes in an arbitration domain, where the plurality of sending nodes include a plurality of source counters; broadcasting, by the sending node and in response to selecting the sending node, a transmitter arbitration request for the timeslot during the arbitration interval; receiving, by the plurality of sending nodes, the transmitter arbitration request; incrementing the plurality of source counters in response to receiving the transmitter arbitration request; and sending, during the timeslot, a data item from the sending node to a receiving node via an optical data channel.

Abstract: An integrated circuit that includes an optical waveguide to convey an optical signal via an optical mode in an on-chip optical waveguide is described. In this integrated circuit, a cross-sectional area of the optical waveguide may be tapered in proximity to an electro-optic modulator in the integrated circuit, such as a germanium electro-optic modulator or a quantum-well (QW) electro-optic modulator. In particular, the cross-sectional area may be tapered from a first diameter distal from the electro-optic modulator to a second diameter proximate to the electro-optic modulator. This so-called ‘inverse taper’ may increase the spatial extent or size of the optical mode, thereby allowing the optical signal to be optically coupled to or from the electro-optic modulator with low optical loss.

Abstract: A multi-chip module (MCM) is described. This MCM includes multiple sites, where a given site in the multiple sites includes multiple chips with proximity connectors that communicate information through proximity communication within the MCM via multiple components associated with the given site. Note that the MCM includes global redundancy and local redundancy at the given site. In particular, the global redundancy involves providing one or more redundant sites in the multiple sites. Furthermore, the local redundancy involves providing one or more redundant chips in the multiple chips and one or more redundant components in the multiple components.

Abstract: A method for arbitration in an arbitration domain. The method includes: receiving, by each node of a plurality of nodes in the arbitration domain, an arbitration request from each sending node of the plurality of nodes in the arbitration domain, where the plurality of nodes in the arbitration domain each use a shared data channel to send data to a set of receiving nodes; assigning, by each node in the arbitration domain, consecutive time slots to each sending node based on a plurality of priorities assigned to the plurality of nodes in the arbitration domain; for each time slot: sending, from the arbitration domain, a switch request to a receiving node designated by the sending node, where the receiving node is in the set of receiving nodes; and sending, by the sending node, data to the receiving node via the shared data channel during the time slot.

Abstract: A multi-chip module (MCM), which includes a three-dimensional (3D) stack of chips that are coupled using optical interconnects, is described. In this MCM, disposed on a first surface of a middle chip in the 3D stack, there are: a first optical coupler, an optical waveguide, which is coupled to the first optical coupler, and a second optical coupler, which is coupled to the optical waveguide. The first optical coupler redirects an optical signal from the optical waveguide to a first direction (which is not in the plane of the first surface), or from the first direction to the optical waveguide. Moreover, the second optical coupler redirects the optical signal from the optical waveguide to a second direction (which is not in the plane of the first surface), or from the second direction to the optical waveguide. Note that an optical path associated with the second direction passes through an opening in a substrate in the middle chip.

Abstract: A multi-chip module (MCM) is described. This MCM includes two substrates having facing surfaces. Disposed on a surface of a first of these substrates, there is an optical waveguide, having an eigenmode in the plane of the surface, and an optical coupler, which redirects optical signals to and/or from the optical waveguide and a direction normal to the surface. Furthermore, disposed on a surface of a second of the substrates, which faces the surface of the first substrate, and which overlaps the optical coupler, there is an optoelectronic device. This optoelectronic device, which has an eigenmode in a direction perpendicular to the surface of the second substrate, selectively receives or provides the optical signal to and/or from the optical coupler. For example, the selective receiving or providing may be controlled by selectively applying a potential to the quantum-well device, thereby changing the optical properties of the optoelectronic device.

Abstract: An optical module is described. This optical module includes at least two optical devices that communicate with each other using edge-to-edge optical coupling of an optical signal between optical components in the two optical devices. Note that the edge-to-edge optical coupling may occur without mode converters at edges of either of the optical devices. Furthermore, the edge-to-edge optical coupling may be facilitated by an alignment substrate, which is mechanically coupled to the two optical devices. This alignment substrate aligns the edges of the two optical devices so that they are approximately parallel to each other, and aligns the optical components in the two optical devices.

Abstract: Embodiments of a system are described. This system includes an array of chip modules (CMs) that are configured to communicate data signals with each other via optical communication. In a given CM module, optical signal paths, such as waveguides, are routed in the same way as in the other CMs in the array. In this way, a common optical design in the CMs may be used in the system to prevent data conflicts during the optical communication.

Abstract: An optical device that includes multiple optical modulators having actual operating wavelengths at a given temperature is described. Because of differences between the actual operating wavelengths and target operating wavelengths of the optical modulators, heating elements may be used to thermally tune the optical modulators so that the actual operating wavelengths match corresponding carrier wavelengths in a set of optical signals. Furthermore, control logic in the optical device may assign the optical modulators to the corresponding carrier wavelengths based at least on differences between the carrier wavelengths and the actual operating wavelengths, thereby reducing an average thermal tuning energy associated with the heating elements.

Abstract: Embodiments of an optical device, an array of optical devices, and a technique for fabricating the optical device or the array are described. This optical device is implemented on a substrate (such as silicon), and includes a thermally tunable optical waveguide that has good thermal isolation from its surroundings. In particular, a portion of a semiconductor in the optical device, which includes the optical waveguide, is free standing above a gap between the semiconductor layer and the substrate. By reducing the thermal coupling between the optical waveguide and the external environment, the optical device can be thermally tuned with significantly less power consumption.

Abstract: Embodiments of an optical device, an array of optical devices, and a technique for fabricating the optical device or the array are described. This optical device is implemented on a substrate (such as silicon), and includes a thermally tunable optical waveguide that has good thermal isolation from its surroundings. In particular, a portion of a semiconductor in the optical device, which includes the optical waveguide, is free standing above a gap between the semiconductor layer and the substrate. By reducing the thermal coupling between the optical waveguide and the external environment, the optical device can be thermally tuned with significantly less power consumption.

Abstract: A system for transmitting data, including: a transmitter node having a setup path packet and multiple data packets; a receiver node connected to the transmitter node by a first optical channel (OC); and a first intermediate node having a first forwarding module and connected to the transmitter node by a second OC and to the receiver node by a third OC, where the transmitter node transmits the setup path packet and a first subset of the multiple data packets to the first intermediate node using the second OC, where the first forwarding module relays, in response to receiving the setup packet, the first subset to the receiver node by switching the first subset from the second OC to the third OC, and where the receiver node receives a second subset of the multiple data packets from the transmitter node using the first OC.

Abstract: Embodiments of a system are described. This system includes an array of chip modules (CMs) that are configured to communicate data signals with each other via optical communication. In a given CM module, optical signal paths, such as waveguides, are routed in the same way as in the other CMs in the array. In this way, a common optical design in the CMs may be used in the system to prevent data conflicts during the optical communication.

Abstract: Embodiments of an optical device, an array of optical devices, and a technique for fabricating the optical device or the array are described. This optical device is implemented on a substrate (such as silicon), and includes a thermally tunable optical waveguide with a high thermal resistance to the surrounding external environment and a low thermal resistance to a localized heater. In particular, the thermal resistances associated with thermal dissipation paths from a heater in the optical device to an external environment via electrodes and via the substrate are increased, while the thermal resistance between the optical waveguide and the heater is decreased.

Abstract: Embodiments of an optical device, an array of optical devices, and a technique for fabricating the optical device or the array are described. This optical device is implemented using two semiconductor layers (such as silicon), one of which includes a heater and the other includes a thermally tunable optical waveguide. Spatially separating these two functions in the optical device results in more efficient heat transfer between the heater and the optical waveguide, reduced heat transfer to the surroundings, and reduced optical losses in the optical waveguide relative to existing silicon-based optical devices.

Abstract: Embodiments of an optical device, an array of optical devices, and a technique for fabricating the optical device or the array are described. This optical device is implemented on a substrate (such as silicon), and includes a thermally tunable optical waveguide that has good thermal isolation from its surroundings. In particular, a portion of a semiconductor in the optical device, which includes the optical waveguide, is free standing above a gap between the semiconductor layer and the substrate. By reducing the thermal coupling between the optical waveguide and the external environment, the optical device can be thermally tuned with significantly less power consumption.

Abstract: A phase modulation waveguide structure includes one of a semiconductor and a semiconductor-on-insulator substrate, a doped semiconductor layer formed over the one of a semiconductor and a semiconductor-on-insulator substrate, the doped semiconductor portion including a waveguide rib protruding from a surface thereof not in contact with the one of a semiconductor and a semiconductor-on-insulator substrate, and an electrical contact on top of the waveguide rib. The electrical contact is formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the waveguide rib and the electrical contact and lower than the optical refractive index of the doped semiconductor layer. During propagation of an optical mode within the waveguide structure, the electrical contact isolates the optical mode between the doped semiconductor layer and a metal electrode contact on top of the electrical contact.