Abstract: An optical source includes a set of N light sources that provide a corresponding set of N optical signals having N carrier wavelengths. These optical signals are combined into a seed optical signal and transported to a substrate using an optical fiber. This substrate includes a set of K optical amplifiers that amplify the seed optical signal and provide a set of M output optical signals on a corresponding set of M output optical waveguides (where M is less than K). In this way, a total power of the set of M output optical signals may be significantly larger than that of the seed optical signal, thereby ensuring that a majority of a power efficiency of the optical source is associated with power efficiencies of the set of K optical amplifiers instead of power efficiencies of the set of N light sources.

Abstract: A chip package includes a substrate having a positive feature, which is defined on a surface of the substrate and which protrudes above a region on the surface proximate to the positive feature. Furthermore, the chip package includes a mechanical reinforcement mechanism defined on the substrate proximate to the positive feature that increases a lateral shear strength of the positive feature relative to the substrate. In this way, the chip package may facilitate increased reliability of a multi-chip module (MCM) that includes the chip package.

Abstract: A multi-chip module (MCM) that includes at least two substrates, having facing surfaces, which are mechanically coupled by a set of coupling elements having a reflow characteristic, is described. One of the two substrates includes another set of coupling elements having another reflow characteristic, which is different than the reflow characteristic. These different reflow characteristics of the sets of coupling elements allow different temperature profiles to be used when bonding the two substrates to each other than when bonding the one of the two substrates to a carrier. For example, the temperature profiles may have different peak temperatures and/or different durations from one another. These reflow characteristics may facilitate low-cost, high-yield assembly and alignment of the substrates in the MCM, and may allow temperature-sensitive components to be included in the MCM.

Abstract: A chip package is described which includes a first chip having a first surface and first sides having a first side-wall angle, and a second chip having a second surface and second sides having a second side-wall angle, which faces and is mechanically coupled to the first chip. The chip package is fabricated using a batch process, and the chips in the chip package were singulated from their respective wafers after the chip package is assembled. This is accomplished by etching the first and second side-wall angles and thinning the wafer thicknesses prior to assembling the chip package. For example, the first and/or the second side walls can be fabricated using wet etching or dry etching. Therefore, the first and/or the second side-wall angles may be other than vertical or approximately vertical.

Abstract: An optical device implemented on a substrate (such as silicon) is described. This optical device includes a wavelength-sensitive optical component with a high thermal resistance to a surrounding external environment and a low thermal resistance to a localized thermal-tuning mechanism (such as a heater), which modifies a temperature of the wavelength-sensitive optical component, thereby specifying an operating wavelength of the wavelength-sensitive optical component. In particular, the thermal resistance associated with a thermal dissipation path from the thermal-tuning mechanism to the external environment via the substrate is increased by removing a portion of the substrate to create a gap that is proximate to the thermal-tuning mechanism and the wavelength-sensitive optical component. Furthermore, the optical device includes a binder material mechanically coupled to the substrate and proximate to the gap, thereby maintaining a mechanical strength of the optical device.

Abstract: An optical connector is described. This optical connector spatially segregates optical coupling between an optical fiber and an optical component, which relaxes the associated mechanical-alignment requirements. In particular, the optical connector includes an optical spreader component disposed on a substrate. This optical spreader component is optically coupled to the optical fiber at a first coupling region, and is configured to optically couple to the optical component at a second coupling region that is at a different location on the substrate than the first coupling region. Moreover, the first coupling region and the second coupling region are optically coupled by an optical waveguide.

Abstract: An optical connector is described. This optical connector spatially segregates optical coupling between an optical fiber and an optical component, which relaxes the associated mechanical-alignment requirements. In particular, the optical connector includes an optical spreader component disposed on a substrate. This optical spreader component is optically coupled to the optical fiber at a first coupling region, and is configured to optically couple to the optical component at a second coupling region that is at a different location on the substrate than the first coupling region. Moreover, the first coupling region and the second coupling region are optically coupled by an optical waveguide.

Abstract: In an MCM, an optical signal is conveyed by an optical waveguide disposed on a surface of a first substrate to a first optical coupler. This first optical coupler redirects the optical signal out of the plane of the optical waveguide. Then, an optical interposer guides the optical signal between the first optical coupler and a second optical coupler on a surface of a second substrate, thereby reducing spatial expansion of the optical signal between the optical couplers. Moreover, the second optical coupler redirects the optical signal into a plane of an optical waveguide disposed on a surface of the second substrate, which then conveys the optical signal.

Abstract: In an MCM, an optical signal is conveyed by an optical waveguide disposed on a surface of a first substrate to an optical coupler having a vertical facet. This optical coupler has an optical mode that is different than the optical mode of the optical waveguide. For example, the spatial extent of the optical mode associated with the optical coupler may be larger, thereby reducing optical losses and sensitivity to alignment errors. Then, the optical signal is directly coupled from the vertical facet to a facing vertical facet of an identical optical coupler on another substrate, and the optical signal is conveyed in another optical waveguide disposed on the other substrate.

Abstract: A processing technique facilitating the fabrication of the integrated circuit with microsprings at different vertical positions relative to a surface of a substrate is described. During the fabrication technique, microsprings are lithographically defined on surfaces of a first substrate and a second substrate. Then, a hole is created through a first substrate. Moreover, the integrated circuit may be created by rigidly mechanically coupling the two substrates to each other such that the microsprings on the surface of the second substrate are within a region defined at least in part by an edge around the hole. Subsequently, photoresist that constrains the microsprings on the surfaces of the two substrates may be removed. In this way, microsprings at the different vertical positions can be fabricated.

Abstract: An MCM includes a two-dimensional array of facing chips, including island chips and bridge chips that communicate with each other using overlapping connectors. In order to maintain the relative vertical spacing of these connectors, compressible structures are in cavities in a substrate, which house the bridge chips, provide a compressive force on back surfaces of the bridge chips. These compressible structures include a compliant material with shape and volume compression. In this way, the MCM may ensure that facing surfaces of the island chips and the bridge chips, as well as connectors on these surfaces, are approximately coplanar without bending the bridge chips.

Abstract: An optical source includes a set of N light sources that provide a corresponding set of N optical signals having N carrier wavelengths. These optical signals are combined into a seed optical signal and transported to a substrate using an optical fiber. This substrate includes a set of K optical amplifiers that amplify the seed optical signal and provide a set of M output optical signals on a corresponding set of M output optical waveguides (where M is less than K). In this way, a total power of the set of M output optical signals may be significantly larger than that of the seed optical signal, thereby ensuring that a majority of a power efficiency of the optical source is associated with power efficiencies of the set of K optical amplifiers instead of power efficiencies of the set of N light sources.

Abstract: In an MCM, an optical signal is conveyed by an optical waveguide disposed on a surface of a first substrate to a first optical coupler. This first optical coupler redirects the optical signal out of the plane of the optical waveguide. Then, an optical interposer guides the optical signal between the first optical coupler and a second optical coupler on a surface of a second substrate, thereby reducing spatial expansion of the optical signal between the optical couplers. Moreover, the second optical coupler redirects the optical signal into a plane of an optical waveguide disposed on a surface of the second substrate, which then conveys the optical signal.

Abstract: During operation of an electro-absorption modulator, an optical signal is conveyed, using an optical waveguide in the electro-absorption modulator, to a semiconductor layer that substantially fills a gap between two portions of the optical waveguide. Then, the optical signal is electro-absorption modulated by selectively applying a voltage to electrodes that produces an electric field, approximately perpendicular to the midline of the optical waveguide, in the semiconductor layer. These electrodes are coupled to the edges of the semiconductor layer at the periphery along the width of the semiconductor layer by intervening layers. Furthermore, the intervening layers include a material that has a lower index of refraction than the semiconductor layer, and a lower optical absorption than the electrodes.

Abstract: In an MCM, an optical signal is conveyed by an optical waveguide disposed on a surface of a first substrate to an optical coupler having a vertical facet. This optical coupler has an optical mode that is different than the optical mode of the optical waveguide. For example, the spatial extent of the optical mode associated with the optical coupler may be larger, thereby reducing optical losses and sensitivity to alignment errors. Then, the optical signal is directly coupled from the vertical facet to a facing vertical facet of an identical optical coupler on another substrate, and the optical signal is conveyed in another optical waveguide disposed on the other substrate.

Abstract: A hybrid integrated module includes a semiconductor die mechanically coupled face-to-face to an integrated device in which the substrate has been removed. For example, the integrated circuit may include an optical waveguide that conveys an optical signal, which is fabricated on a silicon-on-insulator (SOI) wafer in which the back-side silicon substrate or handler has been completely removed. Moreover, an optical device may be disposed on the bottom surface of an oxide layer (such as a buried-oxide layer) in the integrated device, and the geometry and materials in the integrated device may be selected and/or defined so that the optical signal is evanescently coupled between the optical waveguide and the optical device.

Abstract: An integrated circuit that includes an optical waveguide defined in a semiconductor layer is described. In this integrated circuit, light is coupled between the optical waveguide and an optical modulator, which is disposed on the optical waveguide, using 3-dimensional (3-D) taper structures that are proximate to the ends of the optical modulator. The cross-sectional areas of these 3-D taper structures transition, over a distance, from that of the optical waveguide (distal from the optical modulator) to that of optical modulator (proximate to the ends of the optical modulator). In this way, a spatial extent of an optical mode in the optical waveguide and a spatial extent of the optical mode in the optical modulator may be approximately matched to reduce the optical loss when the light is coupled to or from the optical modulator.

Abstract: A method of arbitrating data transmissions to prevent data collisions in an optical data interconnect system including a transmitting node, a plurality of receiving nodes, and one or more remaining nodes connected through an optical data channel. The method involves transmitting a transmission request signal from the transmitting node over an arbitration channel corresponding to the transmitting node, monitoring, at the transmitting node, a plurality of arbitration channels corresponding to each of the plurality of receiving nodes and the one or more remaining nodes at the transmitting node for a predetermined period of time, determining a start time for a data transmission from the transmitting node based on the monitored signals to prevent a data collision, and initiating a data transmission of a data signal from the transmitting node over the optical data channel at the determined start time.

Abstract: An integrated circuit is described. This integrated circuit includes an optical waveguide defined in a semiconductor layer, and an optical detector disposed on top of the optical waveguide. Moreover, the optical waveguide has an end with a reflecting facet. For example, the reflective facet may be defined using an anisotropic etch of the semiconductor layer. This reflecting facet reflects light propagating in a plane of the optical waveguide out of the plane into the optical detector, thereby providing a photodetector with high optical responsivity, including an extremely low dark current (and, thus, high photosensitivity) and an extremely small capacitance (and, thus, high electrical bandwidth).

Abstract: In a hybrid integrated module, a semiconductor die is mechanically coupled face-to-face to an integrated device in which the substrate has been removed. For example, the integrated circuit may include an optical device fabricated on a silicon-on-insulator (SOI) wafer in which the backside silicon handler has been completely removed, thereby facilitating improved device performance and highly efficient thermal tuning of the operating wavelength of the optical device. Moreover, the semiconductor die may be a VLSI chip that provides power, and serves as a mechanical handler and/or an electrical driver. The thermal tuning efficiency of the substrateless optical device may be enhanced by over 100× relative to an optical device with an intact substrate, and by 5× relative to an optical device in which the substrate has only been removed in proximity to the optical device.