Abstract: A method for adjusting the value of the characteristic impedance Zo of a microstrip transmission line printed on an outer layer of a printed circuit board (PCB) comprises performing a post-manufacturing process directly on the artwork of a production PCB.

Abstract: A network element (36) includes circuitry and at least one port (72). The at least one port is coupled to an optical fabric (32) including one or more optical switches (40) that provide optical paths between the at least one port and multiple destination nodes, at predefined time slots. The circuitry is configured to hold a schedule plan (84) that specifies which of the destination nodes are accessible via the optical fabric at which of the time slots, to queue packets that are destined to the destination nodes, and to transmit the queued packets via the at least one port in accordance with the schedule plan.

Abstract: A universal multi-core fiber (UMCF) interconnect includes multiple optical fiber cores and a shared cladding. Each of the optical fiber cores is configured to convey first optical communication signals having a first carrier wavelength using multi-mode propagation, and to convey second optical communication signals having a second carrier wavelength using single-mode propagation. The shared cladding encloses the multiple optical fiber cores.

Abstract: An electro-optical (EO) interconnect assembly includes an optical fiber, and first and second EO transceivers. The first and second EO transceivers, which are coupled to respective ends of the optical fiber, are configured to (i) connect to respective first and second network devices, (ii) exchange electrical signals with the first and second network devices, (iii) convert between the electrical signals and optical signals, and exchange the optical signals with one another over the optical fiber, and (iv) conduct with one another, over the optical fiber, a secure challenge-response transaction, and to initiate a responsive action upon failure of the challenge-response transaction.

Abstract: A layout for a vertical-cavity surface-emitting laser (VCSEL) is provided. In an example embodiment, the layout comprises a VCSEL, an etched shape around a mesa of the VCSEL, a signal contact layer deposited on section of the mesa, and a ground contact layer. The ground contact layer comprises three parts and is positioned around a first section of the etched shape. The first part of the ground contact layer is deposited on a second section of the etched shape. The second and third parts of the ground contact layer comprise two legs off of the first part. The two legs are symmetrically positioned about two sides of the signal contact layer to form a ground-signal-ground configuration.

Abstract: A vertical-cavity surface-emitting laser (VCSEL) is provided. The VCSEL includes a mesa structure disposed on a substrate. The mesa structure has a first reflector, a second reflector, and an active cavity material structure disposed between the first and second reflectors. The mesa structure defines an optical window through which the VCSEL is configured to emit light. The mesa structure further includes a passivation layer disposed at least within the optical window. The passivation layer is designed to seal the mesa structure to reduce the humidity sensitivity of the VCSEL and to protect the VCSEL from contaminants. The passivation layer also provides an improvement in overshoot control, broader modulation bandwidth, and faster pulsing of the VCSEL such that the VCSEL may provide a high speed, high bandwidth signal with controlled overshoot and dumping behavior.

Abstract: An optoelectronic device includes a substrate and first thin film layers disposed on the substrate and patterned to define a vertical-cavity surface-emitting laser (VCSEL), which is configured to emit optical radiation along an optical axis perpendicular to the substrate. Second thin film layers are disposed over the first thin film layers and are patterned to define an optical modulator in which the optical radiation propagates in a direction parallel to the substrate, and an optical coupler configured to couple the optical radiation from the VCSEL into the optical modulator.

Abstract: Embodiments are disclosed for driving a vertical cavity surface emitting laser (VCSEL). An example method includes injecting, via a universal driver, a direct current (DC) bias current to a VCSEL. The VCSEL is configured to convert the modulated signal into an optical signal encoding one or more bits. The example method further includes providing a modulated signal to the VCSEL. The modulated signal encodes a digital sequence comprising the one or more bits using a modulation method.

Abstract: A network device includes an enclosure, a multi-chip module (MCM), an optical-to-optical connector, and a multi-core fiber (MCF) interconnect. The enclosure has a panel. The MCM is inside the enclosure. The optical-to-optical connector, which is mounted on the panel of the enclosure, is configured to transfer a plurality of optical communication signals. The MCF interconnect has a first end coupled to the MCM and a second end connected to the optical-to-optical connector on the panel, for routing the plurality of optical communication signals between the MCM and the panel.

Abstract: Methods for fabricating vertical cavity surface emitting lasers (VCSELs) on a large wafer are provided. An un-patterned epi layer form is bonded onto a first reflector form. The first reflector form includes a first reflector layer and a wafer of a first substrate type. The un-patterned epi layer form includes a plurality of un-patterned layers on a wafer of a second substrate type. The first and second substrate types have different thermal expansion coefficients. A resulting bonded blank is substantially non-varying in a plane that is normal to an intended emission direction of the VCSEL. A first regrowth is performed to form first regrowth layers, some of which are patterned to form a tunnel junction pattern. A second regrowth is performed to form second regrowth layers. A second reflector form is bonded onto the second regrowth layers, wherein the second reflector form includes a second reflector layer.

Abstract: A network device includes an enclosure, a multi-chip module (MCM), an optical-to-optical connector, and a multi-core fiber (MCF) interconnect. The enclosure has a panel. The MCM is inside the enclosure. The optical-to-optical connector, which is mounted on the panel of the enclosure, is configured to transfer a plurality of optical communication signals. The MCF interconnect includes multiple fiber cores for routing the plurality of optical communication signals between the MCF and the panel. The MCF has a first end at which the multiple fiber cores are coupled to the MCM, and a second end at which the multiple fiber cores are connected to the optical-to-optical connector on the panel.

Abstract: A VCSEL includes an active region between a top distributed Bragg reflector (DBR) and a bottom DBR each having alternating GaAs and AlGaAs layers. The active region includes quantum wells (QW) confined between top and bottom GaAs-containing current-spreading layers (CSL), an aperture layer having an optical aperture and a tunnel junction layer above the QW. A GaAs intermediate layer configured to have an open top air gap is disposed over a boundary layer of the active region and the top DBR. The air gap is made wider than the optical aperture and has a height equal to one quarter of VCSEL's emission wavelength in air. The top DBR is attached to the intermediate layer by applying wafer bonding techniques. VCSEL output, the air gap, and the optical aperture are aligned on the same optical axis. The bottom DBR is epitaxially grown on a silicon or a GaAs substrate.

Abstract: Embodiments are disclosed for a lookup table-based coding mechanism for communication systems. An example method includes receiving a signal to be transmitted, converting the signal into a converted analog signal using a digital to analog converter, receiving channel state information for a channel, calibrating the lookup table based on the channel state information, utilizing the calibrated lookup table to generate a coded analog signal based on the converted signal, and transmitting the coded analog signal, wherein the coded signal compensates for channel distortion of the channel.

Abstract: A modulator and method of fabrication thereof are provided. In various embodiments, the modulator is a Franz-Keldysh (FK) effect electro-absorption modulator. In an example embodiment, the modulator comprises a waveguide column formed from waveguide material deposited onto a substrate; a first contact layer doped with a P-type dopant and deposited on a first side of the waveguide column; a second contact layer doped with an N-type dopant and deposited on a second side of the waveguide column; and first and second contacts. The first contact is in electrical communication with the first contact layer and the second contact is in electrical communication with the second contact layer.

Abstract: A vertical-cavity surface-emitting laser (VCSEL) is provided that includes a mesa structure disposed on a substrate. The mesa structure defines an emission axis of the VCSEL. The mesa structure includes a first reflector, a second reflector, and a cascaded active region structure disposed between the first reflector and the second reflector. The cascaded active region structure includes a plurality of cascaded active region layers disposed along the emission axis, where each of the cascade active region layers includes an active region having multi-quantum well and/or dots layers (MQLs), a tunnel junction aligned with the emission axis, and an oxide confinement layer. The oxide confinement layer is disposed between the tunnel junction and MQLs, and has an electrical current aperture defined therein. The mesa structure defines an optical window through which the VCSEL is configured to emit light.

Abstract: A distributed computing network includes a quantum computation network and a processor. The quantum computation network includes one or more quantum processor units (QPUs) interconnected one with the other using quantum interconnects including each a quantum link and quantum network interface cards (QNICs), where each QPU is further connected to, using the QNIC, a quantum memory. The processor is configured to receive a quantum computation task, and, using a network interface card (NIC) (i) allocate the quantum computation task to the computation network, by activating any of the quantum interconnects between the QPUs according to the quantum computation task, and (ii) solve the quantum computation task using the quantum computation network.

Abstract: In one embodiment, an optical network system including a plurality of optical switches configured to switch beams of light which are modulated to carry information, a plurality of host computers comprising respective optical network interface controllers (NICs), optical fibers connecting the optical NICs and the optical switches forming an optically-switched communication network, over which optical circuit connections are established between pairs of the optical NICs over ones of the optical fibers via ones of the optical switches, the optically-switched communication network which including the optical NICs and the optical switches.

Abstract: An optical coupler and method of assembly are described that provide efficient coupling from the photonic integrated circuit (PIC) waveguide layer to external components, such as optical fibers, VCSELs, photodetectors, and gain blocks, among others. The optical coupler includes a PIC that can be supported by a printed circuit board, an optoelectronic transducer supported by the PIC that can convert between optical signals and corresponding electrical signals, and a coupled waveguide assembly. The coupled waveguide assembly includes a low-index waveguide, a high-index waveguide, and a reflective surface that changes a pathway of the optical signals to direct the optical signals from the optoelectronic transducer into the low-index waveguide or from the low-index waveguide into the optoelectronic transducer.

Abstract: One or more blocks of dynamic random access memory are embedded together with a processor and a data bus on an integrated circuit. The data bus has a bandwidth b for general operation including memory access, the block of dynamic random access memory further requiring data refresh at a refresh rate r. The block thus forms an eDRAM on the integrated circuit, typically an ASIC. A refresh controller embedded with the eDRAM may control refresh by clocking the data bus at a rate higher than the rate of the data bus to accommodate both the required memory access and the required data refresh.

Abstract: A tunable vertical-cavity surface-emitting laser (VCSEL) is provided. The VCSEL includes a VCSEL emission structure, piezoelectric material, and a piezoelectric electrode. The VCSEL emission structure includes a first reflector; a second reflector; and an active cavity material structure disposed between the first and second reflectors. The active cavity material structure includes an active region. The piezoelectric material is mechanically coupled to the VCSEL emission structure such that when the piezoelectric material experiences a mechanical stress, the mechanical stress is transferred to the active cavity material structure of the VCSEL emission structure. The piezoelectric electrode is designed to cause an electric field within the piezoelectric material.