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Fuad E. Doany

Fuad E. Doany
IBM · Communication and Computation Subsystems

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145
Publications
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4,107
Citations

Publications

Publications (145)
Conference Paper
We demonstrate a fully-packaged digitally programmable 8×8 strictly nonblocking electrooptic silicon photonics switch module. We measured fiber-to-fiber loss between 7.5 and 10.5 dB, crosstalk <−30 dB, and reconfiguration time <10 ns.
Article
We present a strictly nonblocking 4×4 electrooptic silicon photonic switch fabric with on-chip gain. The switch integrates 12 Mach-Zehnder cells in a 3-stage topology equipped with fast electrooptic phase shifters, and thermooptic phase trimmers. To compensate for the losses of the fabric, a 4-channel GaInAsP/InP semiconductor optical amplifier arr...
Conference Paper
We report on efforts to develop a high speed, low cost, low energy chip scale optical module for co-packaging on a first-level organic substrate for HPC and Data Center applications.
Conference Paper
We report on efforts to develop optical and electrically packaged photonic switch modules in monolithically integrated CMOS technology and to interface these modules with an FPGA-based control plane facilitating reconfiguration in tens of nanoseconds.
Conference Paper
We present a silicon photonic switch assembly integrating a nonblocking 4×4 Mach-Zehnder switch and a flip-chipped SOA array. The switch provides close to net-neutral-loss in the full C-band for all states and shows nanosecond-scale reconfiguration time.
Article
This paper presents an analysis on the loop dynamics of the digital clock and data recovery (CDR) circuits and the design details of a non-return to zero optical receiver (RX) in a 14-nm bulk CMOS finFET technology with high jitter tolerance (JTOL) performance, which is designed based on the analysis. The digital CDR logic is designed full custom i...
Article
A 64-Gb/s high-sensitivity non-return to zero receiver (RX) data-path is demonstrated in the 14-nm-bulk FinFET CMOS technology. To achieve high sensitivity, the RX incorporates a transimpedance amplifier whose gain and bandwidth are co-optimized with a 1-tap decision feedback equalization (DFE). The DFE, which operates at quarter-rate, features a l...
Conference Paper
We demonstrate for the first time a 4x50Gb/s NRZ SWDM VCSEL link over 50m OM4 multimode fiber achieving error free operation (BER<1E-12). Transmission of 4×44Gb/s SWDM over 100m OM4 fiber with error free is also presented.
Article
We demonstrate a 1530 nm VCSEL that can operate error-free without DSP or FEC to 56 Gb/s. At 50 Gb/s, error-free operation is attained up to 2 km of SMF. A two-tap FFE driver is used to precompensate the response of the VCSEL. The optical spectrum of the VCSEL under equalization at 50 Gb/s is analyzed and the chirp properties are reported. The low...
Conference Paper
Hybrid integration of a 4 -- channel semiconductor optical amplifier array onto a silicon photonic carrier with integrated SiN waveguides has been demonstrated. Custom packaging features are designed into the silicon photonic carrier, including efficient waveguide optical coupling structures, an etched trench with metal lines and AuSn solder pads f...
Article
Full-text available
Grating couplers are proposed for polarization-independent coupling of light between a single-mode fiber and a 220-nm-thick channel waveguide on silicon-on-insulator. The grating couplers have nonuniform grating periods that are composed of the intersection or union of a set of two near-optimal TE- and TM-grating periods. The proposed grating coupl...
Conference Paper
We demonstrate a 1530 nm VCSEL that can operate error-free without DSP or FEC to 56 Gb/s. At 50 Gb/s, error-free operation is attained up to 2 km of SMF. A 2-tap FFE driver is used to pre-compensate the VCSEL.
Conference Paper
Full-text available
We have fabricated InP SOAs with lithographically-defined etched facets. Their more precisely-controlled length compared to cleaved SOAs promises improved coupling tolerances for PICs with flip-chip attached gain blocks. Measured gain is around 20dB and noise figures are 5–6dB.
Article
We report on the design, fabrication, packaging and characterization of a 4-channel semiconductor optical amplifier (SOA) flip-chip mounted on a photonic carrier. Significant loss occurs across high radix silicon photonic switching platforms due to multiple switching stages, waveguide crossings and I/O coupling elements. To overcome these losses, w...
Article
Full-text available
The bandwidth capacity of 50/125 μm multimode fiber is extended by using four VCSELs with wavelengths coarsely separated at 30nm and with each wavelength operating at 40Gb/s. All four wavelengths achieve BER <1E-12 at 100m.
Article
Full-text available
We report error free ( $textrm {BER}<10^{-12}$ ) operation of a directly non-return-to-zero modulated 850-nm vertical cavity surface-emitting laser (VCSEL) link operating to 71 Gb/s. This is the highest error free modulation rate for a directly modulated laser of any type. The optical link consists of a 130-nm BiCMOS driver IC with two-tap feed-for...
Conference Paper
A novel optical transceiver with 4 transmitter plus 4 receiver channels designed for coupling to multicore multimode fiber has been fabricated and characterized. The transceiver is based on the holey Optochip concept where 4-channel VCSEL and photodiode arrays are flip-chip attached to a single-chip SiGe IC using AuSn solder. Optical vias (holes) a...
Patent
Full-text available
A differential amplifier stage and method for offset cancellation include an amplifier having an input and an output. An internal offset cancellation circuit has an input for receiving a control signal to control offset cancellation in the amplifier. The offset cancellation circuit is integrated with the amplifier but isolated from the input and th...
Conference Paper
Full-text available
We present complete characterizations of multimode GaAs photodetectors for high-speed VCSEL-based optical links and compare SiGe receiver IC performances in a 62Gbps back-to-back link for different photodiode designs.
Conference Paper
High Performance Computing systems with > 105 optical links are deployed today. Chip-scale optical transceivers for next generation systems can simultaneously achieve high bandwidth and high density while minimizing power and cost.
Conference Paper
Investigation of connector performance for D-shaped multi-core MMF found that worst case equivalent connector offset >5.5m is possible with >2dB loss. Statistical simulations indicate that with proper launch conditions less than 0.75dB loss is possible.
Patent
Full-text available
A method and structure for coupling to a plurality of multicore optical fiber strands. A first plurality of optoelectronic devices is provided on a surface of a substrate, the first optoelectronic devices being arranged in a 2D array pattern that corresponds to a 2D array pattern corresponding to different light cores of a first multicore optical f...
Conference Paper
Optical 4 + 4 transceivers based on holey Optochip design using IBM BiCMOS8HP technology have been successfully assembled and characterized. The transceiver Optochip consists of an 8-channel single chip SiGe IC, containing all of the transmitter (TX) and receiver (RX) amplification circuitry, with flip-chip attached 4-channel VCSEL and photodiode a...
Patent
Fabricating a semiconductor chip with backside optical vias is provided. A silicon wafer is received for processing. The silicon wafer includes an optically transparent oxide layer on a frontside of the silicon wafer. A complementary metal-oxide-semiconductor layer is formed on top of the optically transparent oxide layer. A backside of the silicon...
Conference Paper
Full-text available
We report a directly modulated 850nm VCSEL-based optical link operating at 56.1Gb/s (BER
Article
An electrical packaging platform to support the testing of high-speed IC transceivers with aggregate data rates up to 0.48 Tb/s Tx + 0.48 Tb/s Rx (24 transmitters and 24 receivers up to 20 Gb/s per channel) is presented. The design requirements, potential solutions, and considerations for a successful implementation are discussed together with the...
Article
We report an 850-nm, vertical-cavity surface-emitting laser (VCSEL)-based optical link that achieves new benchmarks in speed and power efficiency. The laser diode driver and receiver ICs are fabricated in standard 90-nm bulk CMOS, and the gallium arsenide optoelectronic devices are commercial components. An operation at a bit-error rate less than 1...
Conference Paper
A compact optical transceiver module providing 0.48 Tb/s transmitter plus 0.48 Tb/s receiver throughput has been demonstrated using a second-generation single-chip holey CMOS transceiver IC. The single-chip CMOS transceiver IC designed in standard 90nm IBM CMOS has 24 receiver and 24 laser driver circuits each with a corresponding through-substrate...
Article
We report here on the design, fabrication and characterization of 48-channel parallel optical transceivers demonstrating terabit/sec data transfer rate. The 0.48 Tb/s transmit plus 0.48 Tb/s receive throughput was achieved using a second-generation single-chip holey CMOS transceiver IC. In addition to 24 receiver (RX) and 24 laser diode driver circ...
Article
We report here on the design, fabrication, and characterization of highly integrated parallel optical transceivers designed for Tb/s-class module-to-module data transfer through polymer waveguides integrated into optical printed circuit boards (o-PCBs). The parallel optical transceiver is based on a through-silicon-via silicon carrier as the platfo...
Article
Full-text available
The effect of applying feed-forward equalization (FFE) on the transmitter side is studied for three different full optical links. In contrast to all previous works, the FFE settings are optimized for a complete link, rather than just the vertical-cavity surface-emitting laser output. The approach results in dramatic improvements in total link perfo...
Article
Future fiber systems in computer communications applications must meet growing bandwidth requirements, while maintaining feasible power and cost targets in addition to maintaining manageable volumes of fiber cabling. Therefore, bandwidth-per-fiber represents a critical design metric for next-generation systems. Here, a multicore fiber technology ba...
Article
Full-text available
This paper describes the design and measured performance of three different silicon photonic switches: a 2$\,\times\,$ 2 switch, a 1$\,\times\,$ 2 switch, and a 4$\,\times\,$ 4 switch. All of the devices have been hybrid integrated with a corresponding custom 90-nm CMOS driver. The 2 $\,\times\,$2 switch is based on a wavelength-insensitive Mach–Ze...
Article
We report an 850-nm, vertical-cavity surface-emitting laser (VCSEL)-based optical link that achieves new benchmarks in speed and power efficiency. The laser diode driver and receiver ICs are fabricated in standard 90-nm bulk CMOS, and the gallium arsenide optoelectronic devices are commercial components. An operation at a bit-error rate less than 1...
Article
Future challenges to bandwidth scaling within computing systems are considered, including the current unsustainable increase in the number of fibers per system. Several approaches to increase the bandwidth per fiber in future systems are outlined.
Conference Paper
We report here on the design, fabrication and characterization of an integrated optical data bus designed for terabit/sec-class module-to-module on-board data transfer using integrated optical transceivers. The parallel optical transceiver is based on a through-silicon-via (TSV) silicon carrier as the platform for integration of 24-channel VCSEL an...
Conference Paper
Full-text available
Optical interconnects are common in today's petascale supercomputers, and will become pervasive at the exascale during this decade. Technologies that can meet the challenging technological and economic requirements for the exascale will be reviewed.
Article
A custom 90-nm bulk digital CMOS switch driver is codesigned and integrated with a silicon photonic switch. A photonic device model is created within the electronic design environment, facilitating driver optimization and performance evaluation prior to fabrication. The fabricated drivers implemented in two variations produce transition times as lo...
Article
Full-text available
We report several firsts for CMOS-driven, VCSEL-based, multimode transmitters and receivers: serial links up to 20 Gb/s; unprecedented full-link power efficiencies from 8 pJ/bit (15 Gb/s) to 17 pJ/bit (20 Gb/s); and >25-Gb/s transmitter operation. OCIS codes: (060.2360) Fiber optics links and subsystems; (060.2380) Fiber optics sources and detector...
Article
Full-text available
Silicon 4x4 switch array based on carrier-injection for switching of multiple 40Gbps WDM channels is reported. Operation in all 9 unique switch states and 12 possible I/O routings is verified with crosstalk less than 10dB.
Article
We report a bidirectional optical link through polymer waveguides integrated on PCB. With 15 channels at 15 Gb/s (BER <10-12 and <10 pJ/bit), the channel and aggregate bandwidths are the highest reported for waveguide interconnects.
Article
A multichannel tapered coupler interfacing standard 250-$\mu$m-pitch low-numerical-aperture (NA) polarization-maintaining fiber arrays with ultradense 20-$\mu$m-pitch high-NA silicon waveguides is designed and fabricated. The coupler is based on an array of 12 dual-core glass waveguides on 250-$\mu$m pitch that are tapered to a 20-$\mu$m pitch, sim...
Conference Paper
Full-text available
The emerging field of silicon photonics targets monolithic integration of optical components in the CMOS process, potentially enabling high bandwidth, high density interconnects with dramatically reduced cost and power dissipation. A broadband photonic switch is a key component of reconfigurable networks which retain data in the optical domain, thu...
Article
A novel, compact 48-channel optical transceiver module has been designed and fabricated based on a "holey" Optochip - a single-chip CMOS transceiver IC with 24 receiver and 24 laser driver circuits each with a corresponding throughsubstrate optical via (hole). The holes enable 24-channel 850-nm VCSEL and photodiode arrays to be directly flip-chip s...
Article
Full-text available
We report here on the design, fabrication, and high-speed performance of a compact 48-channel optical transceiver module enabled by a key novel component: a “holey” Optochip. A single CMOS transceiver chip with 24 receiver (RX) and 24 laser diode driver circuits, measuring 5.2 mm$\,\times\,$5.8 mm, becomes a holey Optochip with the fabrication of f...
Article
Full-text available
We present a 4x4 spatially non-blocking Mach-Zehnder based silicon optical switch fabricated using processes fully compatible with standard CMOS. We successfully demonstrate operation in all 9 unique switch states and 12 possible I/O routing configurations, with worst-case cross-talk levels lower than −9 dB, and common spectral bandwidth of 7 nm. H...
Conference Paper
We report several firsts for CMOS-driven, VCSEL-based, multimode transmitters and receivers: serial links up to 20 Gb/s; unprecedented full-link power efficiencies from 8 pJ/bit (15 Gb/s) to 17 pJ/bit (20 Gb/s); and >;25-Gb/s transmitter operation.
Conference Paper
Today's petascale supercomputers make substantial use of optical interconnects. For the exascale, optics will become pervasive, but must meet challenging technological and economic requirements. The optics technologies that can meet these requirements are reviewed.
Article
We review results on design and development of 4×4 silicon nanophotonic non-blocking switch arrays integrated with driving analog CMOS circuits for circuit-switched optical networks. Such high-radix optical routers are envisioned for future Exascale computer systems.
Article
A 24-channel multimode optical transceiver is developed for interfacing four six-core strands of multicore multimode fiber. The multicore fiber transmitter demonstrates 120-Gb/s/fiber low-crosstalk aggregate transmission, while the receiver has a circuit-limited bandwidth of 15 Gb/s/channel.
Conference Paper
In the last 10 years interconnects in many high performance servers and supercomputers transitioned from copper interconnects to optical interconnects. In this presentation a technological roadmap towards will be reviewed, focusing on the evolution of interconnect power and density efficiencies.
Article
At IBM, we have now developed a first-of-its-kind optical data-transfer system, or bus, built right onto the circuit board. With it, we will soon unveil computer systems 100 times as fast as anything available today. With that much muscle, scientists will at last be able to visualize wondrous things in detail: how the climate will react to man-made...
Conference Paper
Full-text available
Over 100 Gb/s is carried across a single 100-m strand of multicore multimode fiber. A custom VCSEL array transmits 16.7 to 20 Gb/s/channel into six cores housed within a 125-μm cladding. Negligible crosstalk is observed.
Conference Paper
We report here on the design, fabrication and characterization of highly-integrated 3-D Optochips consisting of a Si carrier platform with 4 flip-chip attached components: two 24-channel 850-nm optoelectronic (OE) arrays (VCSELs and photodiodes) and two 24-channel CMOS ICs (receivers and laser drivers). The Si carrier incorporates three copper wiri...
Conference Paper
A novel, compact 48-channel optical transceiver module has been designed and fabricated. At the heart of the assembly is a “holey” Optochip — a single-chip CMOS transceiver integrated circuit (IC) with 24 receiver and 24 laser driver circuits each with a corresponding through-substrate optical via (hole). The holes enable 24-channel 850-nm VCSEL an...
Article
Full-text available
A CMOS driver and broadband silicon photonic switch are co-designed and wire-bond packaged. The integrated switch demonstrates less than 2.1-ns transition times, better than 15-dB extinction, and 5.9-mW total power consumption.
Article
Multimode optical transmitters and receivers are demonstrated with record low power consumptions and at data rates up to 20 Gb/s using 90-nm CMOS analog integrated circuits and GaAs-based VCSELs and photodiodes.
Article
A multichannel tapered coupler interfacing standard 250-μm-pitch low-NA polarization-maintaining fiber arrays with ultra-dense 20-μm-pitch high-NA silicon waveguides is designed, fabricated, and tested, demonstrating coupling losses below 1 dB and injection bandwidths of 160 Gb/s/channel.
Article
We demonstrate VCSEL and PD arrays which operate at 25 Gb/s per channel, 600 Gb/s with 24 channels, for low-power parallel optical module applications. We report a complete 25 Gb/s VCSEL to PD back-to-back link.
Article
24-channel 850nm optical transceiver modules based on silicon carriers with through-silicon electrical and optical vias have been assembled and tested at 12.5Gb/s/channel. Packaged on an organic carrier, the modules enable waveguide-connected multichip modules.
Article
Increasing performance in supercomputers requires a concomitant increase in intrasystem interconnect bandwidth. We review the status and prospects of technologies required to build low power, high density board and chip level interconnects.
Article
We report developments at Emcore on serial 850 nm vertical-cavity surface-emitting lasers (VCSELs) operated up to 25 Gb/s. They have been designed to provide a solution not only to meet stringent 10 Gb/s IEEE and Fiber Channel specifications but also for emerging demands of 17 Gb/s Fiber Channel serial and 100 Gb/s (4x25 Gb/s or 5x20 Gb/s) parallel...
Conference Paper
24-channel 850nm optical transceiver modules based on silicon carriers with through-silicon electrical and optical vias have been assembled and tested at 12.5Gb/s/channel. Packaged on an organic carrier, the modules enable waveguide-connected multichip modules.
Conference Paper
We design, fabricate and demonstrate 850 nm VCSEL and PD arrays which operate at 25 Gb/s per channel, up to 600 Gb/s with 24 channels, for low-power parallel optical module applications. We also report a complete 25 Gb/s VCSEL to PD back-to-back link.
Conference Paper
Multimode optical transmitters and receivers are demonstrated with record low power consumptions and at data rates up to 20 Gb/s using 90-nm CMOS analog integrated circuits and GaAs-based VCSELs and photodiodes.
Article
We have developed parallel optical interconnect technologies designed to support terabit/s-class chip-to-chip data transfer through polymer waveguides integrated in printed circuit boards (PCBs). The board-level links represent a highly integrated packaging approach based on a novel parallel optical module, or Optomodule, with 16 transmitter and 16...
Article
We report here on the design, fabrication, and high-speed performance of a parallel optical transceiver based on a single CMOS amplifier chip incorporating 16 transmitter and 16 receiver channels. The optical interfaces to the chip are provided by 16-channel photodiode (PD) and VCSEL arrays that are directly flip-chip soldered to the CMOS IC. The s...
Article
We report here on a parallel optical transceiver based on a single 0.13 mum CMOS amplifier chip with 16 transmitter and 16 receiver channels. The transceiver is designed to support very low-power, chip-to-chip optical data buses on printed circuit boards at data rates up to 10 Gb/s/channel. Optical interfaces to the chip are provided by 16-channel...
Article
Full-text available
Scaling computing systems to Exaflops (1018 floating point operations per second) will require tremendous increases in communications bandwidth but with greatly reduced power consumption per communicated bit as compared to today's petaflop machines. Reaching the required performance in both density and power consumption will be extremely challengin...
Article
Optical interconnects using polymer waveguides on circuit boards have been demonstrated. Wirebond-free ultradense transceivers provide 160 Gb/s bidirectional throughput with 16 parallel waveguide-connected transmitters and receivers. Initial designs use 985 nm VCSELs. Migration to the industry-standard 850 nm VCSEL wavelength is underway, also prov...
Conference Paper
Full-text available
A parallel optical transceiver module with 24-transmitter plus 24-receiver channels has been designed and fabricated. The transceiver Optochip relies on silicon carrier technology to provide a high level of integration of the electrical and optical components onto a single substrate with high density interconnection. The transceiver Optochip consis...
Conference Paper
A single-chip CMOS parallel optical transceiver, or Optochip, is presented that addresses the key metrics of power consumption, density, bandwidth, and cost, to enable large-scale parallel optical links through fiber or waveguide-arrays.
Article
Full-text available
Aggregate chip bandwidths in server and high performance computing have exceeding Tb/s, and if present trends are to continue would lead to doubling the number of signal pins in each generation. For high bandwidth switch and server applications, bandwidth requirements could exceed the package pin limit as early as 2012. We defined metrics to compar...
Article
We report a compact, low-profile transceiver with 24 transmitter and 24 receiver channels, each operating at 12.5 Gb/s. The achieved 300 Gb/s aggregate bi-directional data rate is the highest ever reported for parallel optical modules.
Article
Full-text available
In this paper we summarize production data from serial 10 Gb/s devices and report on 850 nm VCSEL arrays with channel speeds up to 25 Gb/s. The production data demonstrates that robustness of the basic technology as well as its suitability for cost effective, high volume production. The >10 Gb/s measurements on two dimensional arrays show that 850...
Article
We have demonstrated 160-Gb/s bidirectional optical data buses using parallel optical transceivers with 16-transmitter plus 16-receiver 10-Gb/s channels on optical printed circuit boards with 32 polymer waveguides, providing requisite technologies for chip-to-chip board-level optical interconnects.
Article
Full-text available
The IBM Terabus program has developed parallel optical interconnects for terabit/sec-class chip-to-chip communications through printed circuit boards with integrated optical waveguides. 16 TX + 16 RX channel transceiver "Optomodules" were assembled and fully characterized, with fiber-coupled full links operating up to 15 Gb/s, for an aggregate bi-d...
Conference Paper
A chip-to-chip optical interconnect on a printed circuit board achieves a 160-Gb/s aggregate bidirectional data rate through 32 parallel polymer waveguides at 13.5 mW/Gb/s. This is the fastest, widest, and most integrated optical bus ever demonstrated.