The performance of optical interconnection has improved dramatically in recent years.Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which ...The performance of optical interconnection has improved dramatically in recent years.Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip,but also improves the system performance through advanced heterogeneous integrated packaging.This paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical interconnection.The research status,development trend and application of ultra-low loss optical waveguides,high-speed detectors,high-speed modulators,lasers and 2D,2.5D,3D and monolithic integration are focused on.展开更多
Orbital angular momentum(OAM),described by an azimuthal phase term expej lθT,has unbound orthogonal states with different topological charges l.Therefore,with the explosive growth of global communication capacity,esp...Orbital angular momentum(OAM),described by an azimuthal phase term expej lθT,has unbound orthogonal states with different topological charges l.Therefore,with the explosive growth of global communication capacity,especially for short-distance optical interconnects,light-carrying OAM has proved its great potential to improve transmission capacity and spectral efficiency in the space-division multiplexing system due to its orthogonality,security,and compatibility with other techniques.Meanwhile,100-m freespace optical interconnects become an alternative solution for the“last mile”problem and provide interbuilding communication.We experimentally demonstrate a 260-m secure optical interconnect using OAM multiplexing and 16-ary quadrature amplitude modulation(16-QAM)signals.We study the beam wandering,power fluctuation,channel cross talk,bit-error-rate performance,and link security.Additionally,we also investigate the link performance for 1-to-9 multicasting at the range of 260 m.Considering that the power distribution may be affected by atmospheric turbulence,we introduce an offline feedback process to make it flexibly controllable.展开更多
We describe the structure and testing of one-dimensional array parallel-optics photo-detectors with 16 photodiodes of which each diode operates up to 8 Gb/s. The single element is vertical and top illuminated 30μm-di...We describe the structure and testing of one-dimensional array parallel-optics photo-detectors with 16 photodiodes of which each diode operates up to 8 Gb/s. The single element is vertical and top illuminated 30μm-diameter silicon on insulator （Ge-on-SOI） PIN photodetector. High-quality Ge absorption layer is epitaxially grown on SO1 substrate by the ultra-high vacuum chemical vapor deposition （UHV-CVD）. The photodiode exhibits a good responsivity of 0.20 A/W at a wavelength of 1550 nm. The dark current is as low as 0.36/aA at a reverse bias of 1 V, and the corresponding current density is about 51 mA/cm2. The detector with a diameter of 30 t.trn is measured at an incident light of 1.55 μm and 0.5 mW, and the 3-dB bandwidth is 7.39 GHz without bias and 13.9 GHz at a reverse bias of 3 V. The 16 devices show a good consistency.展开更多
A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP...A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.展开更多
This paper reviews the recently developed optical interconnect technologies designed for scalable, low latency and high-throughput comunications within datacenters or high perforrmnce computers. The three typical arch...This paper reviews the recently developed optical interconnect technologies designed for scalable, low latency and high-throughput comunications within datacenters or high perforrmnce computers. The three typical architectures including the broadcast-and-select based Optical Shared Memory Supercomputer Interconnect System （OSMOSIS） switch, the defection routing based Data Vortex switch and the arrayed waveguide grating based Low-latency Interconnect Optical Network Switch （LIONS） switch are discussed in detail. In particular, we investigate the various Ioopback buffering technologies in LIONS and present a proof of principle testbed demonstration showing feasibility of LIONS architecture. Moreover, the performance of LIONS, Data Vortex and OSMOSIS with traditional state-of-the-art electrical switching network based on the Flattened-ButterFly （FBF） architecture in terms of throughput and latency are compared. The sinmlation based perfortmnce study shows that the latency of LIONS is almost independent of the number of input ports and does not saturate even at very high input load.展开更多
This paper analyzes the physical potential, computing performance benefi t and power consumption of optical interconnects. Compared with electrical interconnections, optical ones show undoubted advantages based on phy...This paper analyzes the physical potential, computing performance benefi t and power consumption of optical interconnects. Compared with electrical interconnections, optical ones show undoubted advantages based on physical factor analysis. At the same time, since the recent developments drive us to think about whether these optical interconnect technologies with higher bandwidth but higher cost are worthy to be deployed, the computing performance comparison is performed. To meet the increasing demand of large-scale parallel or multi-processor computing tasks, an analytic method to evaluate parallel computing performance ofinterconnect systems is proposed in this paper. Both bandwidth-limit model and full-bandwidth model are under our investigation. Speedup and effi ciency are selected to represent the parallel performance of an interconnect system. Deploying the proposed models, we depict the performance gap between the optical and electrically interconnected systems. Another investigation on power consumption of commercial products showed that if the parallel interconnections are deployed, the unit power consumption will be reduced. Therefore, from the analysis of computing influence and power dissipation, we found that parallel optical interconnect is valuable combination of high performance and low energy consumption. Considering the possible data center under construction, huge power could be saved if parallel optical interconnects technologies are used.展开更多
Electric router is widely used for multi-core system to interconnect each other. However, with the increasing number of processor cores, the probability of communication conflict between processor cores increases, and...Electric router is widely used for multi-core system to interconnect each other. However, with the increasing number of processor cores, the probability of communication conflict between processor cores increases, and the data delay increases dramatically. With the advent of optical router, the traditional electrical interconnection mode has changed to optical interconnection mode. In the packet switched optical interconnection network, the data communication mechanism consists of 3 processes: link establishment, data transmission and link termination, but the circuit-switched data transmission method greatly limits the utilization of resources. The number of micro-ring resonators in the on-chip large-scale optical interconnect network is an important parameter affecting the insertion loss. The proposed λ-route, GWOR, Crossbar structure has a large overall network insertion loss due to the use of many micro-ring resonators. How to use the least micro-ring resonator to realize non-blocking communication between multiple cores has been a research hotspot. In order to improve bandwidth and reduce access latency, an optical interconnection structure called multilevel switching optical network on chip(MSONoC) is proposed in this paper. The broadband micro-ring resonators(BMRs) are employed to reduce the number of micro-ring resonators(MRs) in the network, and the structure can provide the service of non-blocking point to point communication with the wavelength division multiplexing(WDM) technology. The results show that compared to λ-route, GWOR, Crossbar and the new topology structure, the number of micro-ring resonators of MSONoC are reduced by 95.5%, 95.5%, 87.5%, and 60% respectively. The insertion loss of the minimum link of new topology, mesh and MSONoC structure is 0.73 dB, 0.725 dB and 0.38 dB.展开更多
In recent years, explosively increasing data traffic has been boosting the con?tinuous demand of high speed optical interconnection inside or among data centers, high performance computers and even consumer electronic...In recent years, explosively increasing data traffic has been boosting the con?tinuous demand of high speed optical interconnection inside or among data centers, high performance computers and even consumer electronics. To pursue the improved intercon?nection performance of capacity, energy efficiency and simplicity, effective approaches are demonstrated including particularly advanced digital signal processing (DSP) meth?ods. In this paper, we present a review about the enabling adaptive DSP methods for opti?cal interconnection applications, and a detailed summary of our recent and ongoing works in this field. In brief, our works focus on dealing with the specific issues for short-reach interconnection scenarios with adaptive operation, including signal-to-noise-ratio (SNR) limitation, level nonlinearity distortion, energy efficiency consideration and the de?cision precision.展开更多
The rapid growth of new services has led to a significant increase in data traffic,which brings challenges for data centers in supporting high-speed processing of large volumes of data.Traditional electrical interconn...The rapid growth of new services has led to a significant increase in data traffic,which brings challenges for data centers in supporting high-speed processing of large volumes of data.Traditional electrical interconnects are becoming increasingly inadequate,leading to increasing attention to optical interconnects to achieve high-speed data center interconnects(DCIs).Visible light laser communication(VLLC)inherits the advantages of free-space optics(FSO),allowing it to circumvent the limitations of conventional fiber-based optical interconnects.In addition,VLLC offers other advantages such as high thermal stability,low power consumption,and low packaging cost.In this Letter,a novel differential pilot coding(DPC)scheme is proposed to achieve precise channel estimation and compensation for linear impairments without halving the effective data rate.A data rate of 601.46 Gbps with a constellation size up to 1024QAM over a 1 m multimode fiber(MMF)-1 m FSO-1 m MMF link is successfully achieved based on a 50-channel wavelength division multiplexer(WDM)VLLC system utilizing DPC and bit-power-loading discrete multitone(DMT)modulation.To the best of our knowledge,this is the highest data rate and constellation size ever the reported for a WDM VLLC system,which proves that VLLC is a promising candidate solution for achieving high-capacity and cost-effective optical interconnects in data centers.展开更多
We propose a cost-effective scheme relying exclusively on pilot symbols for robust frame synchronization and high-precision,wide-range carrier recovery in short-reach optical interconnects.Our method mitigates phase o...We propose a cost-effective scheme relying exclusively on pilot symbols for robust frame synchronization and high-precision,wide-range carrier recovery in short-reach optical interconnects.Our method mitigates phase offsets and enhances phase tracking by strategically placing dual-polarization pilot symbols,both aligned and misaligned,within the frame.Compared to traditional carrier recovery schemes,our approach offers a broader frequency offset estimation range,higher carrier recovery accuracy,and significantly lower computational complexity.Experimental results show a 0.7 dB sensitivity improvement at the soft decision forward error correction threshold,outperforming Fourier transform-based frequency offset estimation combined with blind phase search.展开更多
The wavelength routing technology applied to computer interconnection networks is introduced in this paper.By analyzing the relation between wavelength and network routing,we describe a concept of wavelength used as n...The wavelength routing technology applied to computer interconnection networks is introduced in this paper.By analyzing the relation between wavelength and network routing,we describe a concept of wavelength used as network IP address,and propose a wavelength routing topology to extend the scale of a network and realize the scalability of the network.Moreover,a twin wavelength ring network that is being developed in our laboratory to implement and test the function of wavelength routing is presented,and the main units of the twin wavelength ring network are presented also.According to the testing results based on a single wavelength ring network,it proves that the optical interconnection technology is a perfect technology to provide enough communication bandwidth for computer network.展开更多
Explosive growth in demand for data traffic has prompted exploration of the spatial dimension of lightwaves, which provides a degree of freedom to expand data transmission capacity. Various techniques basedon bulky op...Explosive growth in demand for data traffic has prompted exploration of the spatial dimension of lightwaves, which provides a degree of freedom to expand data transmission capacity. Various techniques basedon bulky optical devices have been proposed to tailor light waves in the spatial dimension. However, theirinherent large size, extra loss, and precise alignment requirements make these techniques relativelydifficult to implement in a compact and flexible way. In contrast, three-dimensional (3D) photonic chips withcompact size and low loss provide a promising miniaturized candidate for tailoring light in the spatialdimension. Significantly, they are attractive for chip-assisted short-distance spatial mode optical interconnectsthat are challenging to bulky optics. Here, we propose and fabricate femtosecond laser-inscribed 3D photonicchips to tailor orbital angular momentum (OAM) modes in the spatial dimension. Various functions on theplatform of 3D photonic chips are experimentally demonstrated, including the generation, (de)multiplexing,and exchange of OAM modes. Moreover, chip-chip and chip–fiber–chip short-distance optical interconnectsusing OAM modes are demonstrated in the experiment with favorable performance. This work paves the wayto flexibly tailor light waves on 3D photonic chips and offers a compact solution for versatile opticalinterconnects and other emerging applications with spatial modes.展开更多
We have proposed and experimentally demonstrated a reconfigurable free space optical interconnect with broadcasting capability based on an eight-channel silicon integrated optical phased array.By using the silicon int...We have proposed and experimentally demonstrated a reconfigurable free space optical interconnect with broadcasting capability based on an eight-channel silicon integrated optical phased array.By using the silicon integrated beam steering and broadcasting device,10 Gb/s on-off keying data is transmitted over 15 cm in free space for up to three receivers located in three different cards.The experimental results show that the optical phased array can be used with broadcasting capability provided to multi-receivers in the card to card optical interconnects,which can significantly reduce device size,system complexity,and total costs.展开更多
Optical interconnects （OIs） are the only solution to fulfil both the requirements on large bandwidth and minimum power consumption of data centers and high-performance computers （HPCs）. Vertical-cavity surface-emi...Optical interconnects （OIs） are the only solution to fulfil both the requirements on large bandwidth and minimum power consumption of data centers and high-performance computers （HPCs）. Vertical-cavity surface-emitting lasers （VCSELs） are the ideal light sources for Ols and have been widely deployed. This paper will summarize the progress made on modulation speed, energy efficiency, and temperature stability of VCSELs. Espe- cially VCSELs with surface nanostructures will be reviewed in depth. Such lasers will provide new opportunities to further boost the performance of VCSELs and open a new door for energy-efficient OIs.展开更多
We present compact silicon-arrayed waveguide grating routers （AWGRs） with three different channel spacings of 20, 6.4, and 3.2 nm for optical interconnect systems. The AWGR with the 20 nm channel spacing shows a low...We present compact silicon-arrayed waveguide grating routers （AWGRs） with three different channel spacings of 20, 6.4, and 3.2 nm for optical interconnect systems. The AWGR with the 20 nm channel spacing shows a low loss of 2.5 dB and a low crosstalk of -20 dB and has a footprint of only 0.27 mm× 0.19 mm. The AWGR with the channel spacing of 6.4 nm has loss ranging from 3 to 8 dB, and the crosstalk is -18 dB. As for the 3.2 nm channel spacing, the loss is about 4 dB, and the crosstalk is -12 dB.展开更多
In this Letter, a pair of integrated optoelectronic transceiving chips is proposed. They are constructed by integrating a vertical cavity surface emitting laser unit above a positive-intrinsic-negative photodetector u...In this Letter, a pair of integrated optoelectronic transceiving chips is proposed. They are constructed by integrating a vertical cavity surface emitting laser unit above a positive-intrinsic-negative photodetector unit. One of the transceiving chips emits light at the wavelength of 848.1 nm with a threshold current of 0.8 mA and a slope efficiency of 0.81 W/A. It receives light between 801 and 814 nm with a quantum efficiency of higher than 70%. On its counterpart, the other one of the transceiving chips emits light at the wavelength of 805.3 nm with a threshold current of 1.1 mA and a slope efficiency of 0.86 W/A. It receives light between 838 and 855 nm with a quantum efficiency of higher than 70%. The proposed pair of integrated optoelectronic transceiving chips can work full-duplex with each other, and they can be applied to single fiber bidirectional optical interconnects.展开更多
A mode transformer based on the quasi-vertical taper is designed to enable high coupling efficiency for interboardlevel optical interconnects involving single-mode polymer waveguides and standard single-mode fibers. A...A mode transformer based on the quasi-vertical taper is designed to enable high coupling efficiency for interboardlevel optical interconnects involving single-mode polymer waveguides and standard single-mode fibers. A triangular region fabricated above the waveguide is adopted to adiabatically transform the mode from the fiber into the polymer waveguide. The effects of the geometrical parameters of the taper, including width, height, tip width,etc., on the coupling efficiency are numerically investigated. Based on this, a quasi-vertical taper for the polymer rib waveguide system is designed, fabricated, and characterized. Coupling losses of 1.79 0.30 and 2.23 0.31 dB per coupler for the quasi-TM and quasi-TE mode, respectively, are measured across the optical communication C and L bands(1535 to 1610 nm). Low-cost packaging, leading to widespread utilization of polymeric photonicdevices, is envisioned for optical interconnect applications.展开更多
An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel comput...An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel computing system. It provides an effective way to upgrade the capability of parallel computer by combining optical wavelength division multiplexing (WDM) and data packet switching technology. CWDM used in network construction, optical cross connection (OXC) based on optical switch arrays, and data packet format used in network construction were analyzed. We have also done the optimizing analysis of the number of optical switches needed in different scales of network in this paper. The architecture of the optical interconnection for 8 wavelength channels and 128 bits parallel transmission has been researched. Finally, a parallel transmission system with 4 nodes, 8 channels per node, has been designed.展开更多
A standard CMOS optical interconnect is proposed, including an octagonal-annular emitter, a field oxide, metal 1-PSG/BPSG-metal 2 dual waveguide, and an ultra high-sensitivity optical receiver integrated with a finger...A standard CMOS optical interconnect is proposed, including an octagonal-annular emitter, a field oxide, metal 1-PSG/BPSG-metal 2 dual waveguide, and an ultra high-sensitivity optical receiver integrated with a fingered P＋/N-well/P-sub dual photodiode detector. The optical interconnect is implemented in a Chartered 3.3-V 0.35-μm standard analog CMOS process with two schemes for the research of the substrate noise coupling effect on the optical interconnect performance： with or without a GND-guardring around the emitter. The experiment results show that the optical interconnect can work at 100 kHz, and it is feasible to implement optical interconnects in standard CMOS processes.展开更多
A power-aware transceiver for half-duplex bidirectional chip-to-chip optical interconnects has been designed and fabricated in a 0.13 μm complementary metal-oxide-semiconductor （CMOS） technology. The transceiver ca...A power-aware transceiver for half-duplex bidirectional chip-to-chip optical interconnects has been designed and fabricated in a 0.13 μm complementary metal-oxide-semiconductor （CMOS） technology. The transceiver can detect the presence and absence of received signals and saves 55% power in Rx enabled mode and 45% in Tx enabled mode. The chip occupies an area of 1.034 mm2 and achieves a 3-dB bandwidth of 6 GHz and 7 GHz in Tx and Rx modes, respectively. The disabled outputs for the Tx and Rx modes are isolated with 180 dB and 139 dB, respectively, from the enabled outputs. Clear eye diagrams are obtained at 4.25 Gbps for both the Tx and Rx modes.展开更多
基金Project supported in part by the National Key Research and Development Program of China(Grant No.2021YFB2206504)the National Natural Science Foundation of China(Grant No.62235017)the China Postdoctoral Science Foundation(Grant No.2021M703125).
文摘The performance of optical interconnection has improved dramatically in recent years.Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip,but also improves the system performance through advanced heterogeneous integrated packaging.This paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical interconnection.The research status,development trend and application of ultra-low loss optical waveguides,high-speed detectors,high-speed modulators,lasers and 2D,2.5D,3D and monolithic integration are focused on.
基金supported by the National Natural Science Foundation of China (Grant Nos.62125503,62261160388,and 62101198)the Natural Science Foundation of Hubei Province of China (Grant Nos.2021CFB011 and 2023AFA028)+2 种基金the Key R&D Program of Hubei Province of China (Grant Nos.2020BAB001 and 2021BAA024)Shenzhen Science and Technology Program (Grant No.JCYJ20200109114018750)the Innovation Project of Optics Valley Laboratory (Grant Nos.OVL2021BG004 and OVL2023ZD004).
文摘Orbital angular momentum(OAM),described by an azimuthal phase term expej lθT,has unbound orthogonal states with different topological charges l.Therefore,with the explosive growth of global communication capacity,especially for short-distance optical interconnects,light-carrying OAM has proved its great potential to improve transmission capacity and spectral efficiency in the space-division multiplexing system due to its orthogonality,security,and compatibility with other techniques.Meanwhile,100-m freespace optical interconnects become an alternative solution for the“last mile”problem and provide interbuilding communication.We experimentally demonstrate a 260-m secure optical interconnect using OAM multiplexing and 16-ary quadrature amplitude modulation(16-QAM)signals.We study the beam wandering,power fluctuation,channel cross talk,bit-error-rate performance,and link security.Additionally,we also investigate the link performance for 1-to-9 multicasting at the range of 260 m.Considering that the power distribution may be affected by atmospheric turbulence,we introduce an offline feedback process to make it flexibly controllable.
文摘We describe the structure and testing of one-dimensional array parallel-optics photo-detectors with 16 photodiodes of which each diode operates up to 8 Gb/s. The single element is vertical and top illuminated 30μm-diameter silicon on insulator （Ge-on-SOI） PIN photodetector. High-quality Ge absorption layer is epitaxially grown on SO1 substrate by the ultra-high vacuum chemical vapor deposition （UHV-CVD）. The photodiode exhibits a good responsivity of 0.20 A/W at a wavelength of 1550 nm. The dark current is as low as 0.36/aA at a reverse bias of 1 V, and the corresponding current density is about 51 mA/cm2. The detector with a diameter of 30 t.trn is measured at an incident light of 1.55 μm and 0.5 mW, and the 3-dB bandwidth is 7.39 GHz without bias and 13.9 GHz at a reverse bias of 3 V. The 16 devices show a good consistency.
基金Supported by the National Basic Research Program of China under Grant No 2012CB933501the National Natural Science Foundation of China under Grant Nos 61307033,61274070,61137003 and 61321063
文摘A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.
基金the Department of Defense under Contract No.#H88230-08-C-0202the Google Research Awards
文摘This paper reviews the recently developed optical interconnect technologies designed for scalable, low latency and high-throughput comunications within datacenters or high perforrmnce computers. The three typical architectures including the broadcast-and-select based Optical Shared Memory Supercomputer Interconnect System （OSMOSIS） switch, the defection routing based Data Vortex switch and the arrayed waveguide grating based Low-latency Interconnect Optical Network Switch （LIONS） switch are discussed in detail. In particular, we investigate the various Ioopback buffering technologies in LIONS and present a proof of principle testbed demonstration showing feasibility of LIONS architecture. Moreover, the performance of LIONS, Data Vortex and OSMOSIS with traditional state-of-the-art electrical switching network based on the Flattened-ButterFly （FBF） architecture in terms of throughput and latency are compared. The sinmlation based perfortmnce study shows that the latency of LIONS is almost independent of the number of input ports and does not saturate even at very high input load.
基金supported in part by National 863 Program (2009AA01Z256,No.2009AA01A345)National 973 Program (2007CB310705)the NSFC (60932004),P.R.China
文摘This paper analyzes the physical potential, computing performance benefi t and power consumption of optical interconnects. Compared with electrical interconnections, optical ones show undoubted advantages based on physical factor analysis. At the same time, since the recent developments drive us to think about whether these optical interconnect technologies with higher bandwidth but higher cost are worthy to be deployed, the computing performance comparison is performed. To meet the increasing demand of large-scale parallel or multi-processor computing tasks, an analytic method to evaluate parallel computing performance ofinterconnect systems is proposed in this paper. Both bandwidth-limit model and full-bandwidth model are under our investigation. Speedup and effi ciency are selected to represent the parallel performance of an interconnect system. Deploying the proposed models, we depict the performance gap between the optical and electrically interconnected systems. Another investigation on power consumption of commercial products showed that if the parallel interconnections are deployed, the unit power consumption will be reduced. Therefore, from the analysis of computing influence and power dissipation, we found that parallel optical interconnect is valuable combination of high performance and low energy consumption. Considering the possible data center under construction, huge power could be saved if parallel optical interconnects technologies are used.
基金Supported by the National Natural Science Foundation of China(No.61834005,61772417,61802304,61602377,61634004)Shaanxi Provincial Co-ordination Innovation Project of Science and Technology(No.2016KTZDGY02-04-02)+1 种基金Shaanxi Provincial Key R&D Plan(No.2017GY-060)Shaanxi International Science and Technology Cooperation Program(No.2018KW-006).
文摘Electric router is widely used for multi-core system to interconnect each other. However, with the increasing number of processor cores, the probability of communication conflict between processor cores increases, and the data delay increases dramatically. With the advent of optical router, the traditional electrical interconnection mode has changed to optical interconnection mode. In the packet switched optical interconnection network, the data communication mechanism consists of 3 processes: link establishment, data transmission and link termination, but the circuit-switched data transmission method greatly limits the utilization of resources. The number of micro-ring resonators in the on-chip large-scale optical interconnect network is an important parameter affecting the insertion loss. The proposed λ-route, GWOR, Crossbar structure has a large overall network insertion loss due to the use of many micro-ring resonators. How to use the least micro-ring resonator to realize non-blocking communication between multiple cores has been a research hotspot. In order to improve bandwidth and reduce access latency, an optical interconnection structure called multilevel switching optical network on chip(MSONoC) is proposed in this paper. The broadband micro-ring resonators(BMRs) are employed to reduce the number of micro-ring resonators(MRs) in the network, and the structure can provide the service of non-blocking point to point communication with the wavelength division multiplexing(WDM) technology. The results show that compared to λ-route, GWOR, Crossbar and the new topology structure, the number of micro-ring resonators of MSONoC are reduced by 95.5%, 95.5%, 87.5%, and 60% respectively. The insertion loss of the minimum link of new topology, mesh and MSONoC structure is 0.73 dB, 0.725 dB and 0.38 dB.
基金This work was supported by National Natural Science Foundation of Chi⁃na(NSFC)under Grant Nos.61935011,61875124 and 61875049.
文摘In recent years, explosively increasing data traffic has been boosting the con?tinuous demand of high speed optical interconnection inside or among data centers, high performance computers and even consumer electronics. To pursue the improved intercon?nection performance of capacity, energy efficiency and simplicity, effective approaches are demonstrated including particularly advanced digital signal processing (DSP) meth?ods. In this paper, we present a review about the enabling adaptive DSP methods for opti?cal interconnection applications, and a detailed summary of our recent and ongoing works in this field. In brief, our works focus on dealing with the specific issues for short-reach interconnection scenarios with adaptive operation, including signal-to-noise-ratio (SNR) limitation, level nonlinearity distortion, energy efficiency consideration and the de?cision precision.
基金supported by the National Natural Science Foundation of China(Nos.61925104 and 62031011)the National Key Research and Development Program of China(No.2022YFB2802803)。
文摘The rapid growth of new services has led to a significant increase in data traffic,which brings challenges for data centers in supporting high-speed processing of large volumes of data.Traditional electrical interconnects are becoming increasingly inadequate,leading to increasing attention to optical interconnects to achieve high-speed data center interconnects(DCIs).Visible light laser communication(VLLC)inherits the advantages of free-space optics(FSO),allowing it to circumvent the limitations of conventional fiber-based optical interconnects.In addition,VLLC offers other advantages such as high thermal stability,low power consumption,and low packaging cost.In this Letter,a novel differential pilot coding(DPC)scheme is proposed to achieve precise channel estimation and compensation for linear impairments without halving the effective data rate.A data rate of 601.46 Gbps with a constellation size up to 1024QAM over a 1 m multimode fiber(MMF)-1 m FSO-1 m MMF link is successfully achieved based on a 50-channel wavelength division multiplexer(WDM)VLLC system utilizing DPC and bit-power-loading discrete multitone(DMT)modulation.To the best of our knowledge,this is the highest data rate and constellation size ever the reported for a WDM VLLC system,which proves that VLLC is a promising candidate solution for achieving high-capacity and cost-effective optical interconnects in data centers.
基金supported by the National Key R&D Program of China(No.2022YFB2903103)the National Natural Science Foundation of China(No.62205023)。
文摘We propose a cost-effective scheme relying exclusively on pilot symbols for robust frame synchronization and high-precision,wide-range carrier recovery in short-reach optical interconnects.Our method mitigates phase offsets and enhances phase tracking by strategically placing dual-polarization pilot symbols,both aligned and misaligned,within the frame.Compared to traditional carrier recovery schemes,our approach offers a broader frequency offset estimation range,higher carrier recovery accuracy,and significantly lower computational complexity.Experimental results show a 0.7 dB sensitivity improvement at the soft decision forward error correction threshold,outperforming Fourier transform-based frequency offset estimation combined with blind phase search.
基金Supported by“863” high technology research and developmentprogram,No.863- 30 7- 1 4 - 2 (0 1 )
文摘The wavelength routing technology applied to computer interconnection networks is introduced in this paper.By analyzing the relation between wavelength and network routing,we describe a concept of wavelength used as network IP address,and propose a wavelength routing topology to extend the scale of a network and realize the scalability of the network.Moreover,a twin wavelength ring network that is being developed in our laboratory to implement and test the function of wavelength routing is presented,and the main units of the twin wavelength ring network are presented also.According to the testing results based on a single wavelength ring network,it proves that the optical interconnection technology is a perfect technology to provide enough communication bandwidth for computer network.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.62125503 and 62261160388)the Key R&D Program of Hubei Province of China(Grant Nos.2020BAB001 and 2021BAA024)+2 种基金the Key R&D Program of Guangdong Province(Grant No.2018B030325002)the Shenzhen Science and Technology Program(Grant No.JCYJ20200109114018750)the Innovation Project of Optics Valley Laboratory(Grant No.OVL2021BG004).
文摘Explosive growth in demand for data traffic has prompted exploration of the spatial dimension of lightwaves, which provides a degree of freedom to expand data transmission capacity. Various techniques basedon bulky optical devices have been proposed to tailor light waves in the spatial dimension. However, theirinherent large size, extra loss, and precise alignment requirements make these techniques relativelydifficult to implement in a compact and flexible way. In contrast, three-dimensional (3D) photonic chips withcompact size and low loss provide a promising miniaturized candidate for tailoring light in the spatialdimension. Significantly, they are attractive for chip-assisted short-distance spatial mode optical interconnectsthat are challenging to bulky optics. Here, we propose and fabricate femtosecond laser-inscribed 3D photonicchips to tailor orbital angular momentum (OAM) modes in the spatial dimension. Various functions on theplatform of 3D photonic chips are experimentally demonstrated, including the generation, (de)multiplexing,and exchange of OAM modes. Moreover, chip-chip and chip–fiber–chip short-distance optical interconnectsusing OAM modes are demonstrated in the experiment with favorable performance. This work paves the wayto flexibly tailor light waves on 3D photonic chips and offers a compact solution for versatile opticalinterconnects and other emerging applications with spatial modes.
基金supported by the National Key Research and Development Program of China(No.2019YFB2203203)。
文摘We have proposed and experimentally demonstrated a reconfigurable free space optical interconnect with broadcasting capability based on an eight-channel silicon integrated optical phased array.By using the silicon integrated beam steering and broadcasting device,10 Gb/s on-off keying data is transmitted over 15 cm in free space for up to three receivers located in three different cards.The experimental results show that the optical phased array can be used with broadcasting capability provided to multi-receivers in the card to card optical interconnects,which can significantly reduce device size,system complexity,and total costs.
文摘Optical interconnects （OIs） are the only solution to fulfil both the requirements on large bandwidth and minimum power consumption of data centers and high-performance computers （HPCs）. Vertical-cavity surface-emitting lasers （VCSELs） are the ideal light sources for Ols and have been widely deployed. This paper will summarize the progress made on modulation speed, energy efficiency, and temperature stability of VCSELs. Espe- cially VCSELs with surface nanostructures will be reviewed in depth. Such lasers will provide new opportunities to further boost the performance of VCSELs and open a new door for energy-efficient OIs.
基金supported by the National 863 Program of China(No.2013AA014401)the National Science Foundation of China(No.61605172)
文摘We present compact silicon-arrayed waveguide grating routers （AWGRs） with three different channel spacings of 20, 6.4, and 3.2 nm for optical interconnect systems. The AWGR with the 20 nm channel spacing shows a low loss of 2.5 dB and a low crosstalk of -20 dB and has a footprint of only 0.27 mm× 0.19 mm. The AWGR with the channel spacing of 6.4 nm has loss ranging from 3 to 8 dB, and the crosstalk is -18 dB. As for the 3.2 nm channel spacing, the loss is about 4 dB, and the crosstalk is -12 dB.
基金supported by the Fund of State Key Laboratory of Information Photonics and Optical Communications(No.IPOC2016ZT10)the National Natural Science Foundation of China(Nos.61574019,61674020,and 61674018)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20130005130001)the 111 Project(No.B07005)
文摘In this Letter, a pair of integrated optoelectronic transceiving chips is proposed. They are constructed by integrating a vertical cavity surface emitting laser unit above a positive-intrinsic-negative photodetector unit. One of the transceiving chips emits light at the wavelength of 848.1 nm with a threshold current of 0.8 mA and a slope efficiency of 0.81 W/A. It receives light between 801 and 814 nm with a quantum efficiency of higher than 70%. On its counterpart, the other one of the transceiving chips emits light at the wavelength of 805.3 nm with a threshold current of 1.1 mA and a slope efficiency of 0.86 W/A. It receives light between 838 and 855 nm with a quantum efficiency of higher than 70%. The proposed pair of integrated optoelectronic transceiving chips can work full-duplex with each other, and they can be applied to single fiber bidirectional optical interconnects.
基金supported by Air Force Office of Scientific Research (AFOSR) for supporting this work under the Small Business Technology Transfer Research (STTR) program (grant no. FA9550-14-C-0001)
文摘A mode transformer based on the quasi-vertical taper is designed to enable high coupling efficiency for interboardlevel optical interconnects involving single-mode polymer waveguides and standard single-mode fibers. A triangular region fabricated above the waveguide is adopted to adiabatically transform the mode from the fiber into the polymer waveguide. The effects of the geometrical parameters of the taper, including width, height, tip width,etc., on the coupling efficiency are numerically investigated. Based on this, a quasi-vertical taper for the polymer rib waveguide system is designed, fabricated, and characterized. Coupling losses of 1.79 0.30 and 2.23 0.31 dB per coupler for the quasi-TM and quasi-TE mode, respectively, are measured across the optical communication C and L bands(1535 to 1610 nm). Low-cost packaging, leading to widespread utilization of polymeric photonicdevices, is envisioned for optical interconnect applications.
文摘An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel computing system. It provides an effective way to upgrade the capability of parallel computer by combining optical wavelength division multiplexing (WDM) and data packet switching technology. CWDM used in network construction, optical cross connection (OXC) based on optical switch arrays, and data packet format used in network construction were analyzed. We have also done the optimizing analysis of the number of optical switches needed in different scales of network in this paper. The architecture of the optical interconnection for 8 wavelength channels and 128 bits parallel transmission has been researched. Finally, a parallel transmission system with 4 nodes, 8 channels per node, has been designed.
基金supported by the National Natural Science Foundation of China(Nos.60536030,60676038)the Tianjin Natural Science Foundation(No.06YFJZJC00200)
文摘A standard CMOS optical interconnect is proposed, including an octagonal-annular emitter, a field oxide, metal 1-PSG/BPSG-metal 2 dual waveguide, and an ultra high-sensitivity optical receiver integrated with a fingered P＋/N-well/P-sub dual photodiode detector. The optical interconnect is implemented in a Chartered 3.3-V 0.35-μm standard analog CMOS process with two schemes for the research of the substrate noise coupling effect on the optical interconnect performance： with or without a GND-guardring around the emitter. The experiment results show that the optical interconnect can work at 100 kHz, and it is feasible to implement optical interconnects in standard CMOS processes.
基金Project supported by the IT R&D Program of MKE/KEIT[No.10039230,Development of bidirectional 40 Gbps optical link module with low power in Green Data Centre for Smart Working Environment]the Center for Integrated Smart Sensors funded by the Ministry of Education,Science and Technology as Global Frontier Project(No.CISS-2012366054191)
文摘A power-aware transceiver for half-duplex bidirectional chip-to-chip optical interconnects has been designed and fabricated in a 0.13 μm complementary metal-oxide-semiconductor （CMOS） technology. The transceiver can detect the presence and absence of received signals and saves 55% power in Rx enabled mode and 45% in Tx enabled mode. The chip occupies an area of 1.034 mm2 and achieves a 3-dB bandwidth of 6 GHz and 7 GHz in Tx and Rx modes, respectively. The disabled outputs for the Tx and Rx modes are isolated with 180 dB and 139 dB, respectively, from the enabled outputs. Clear eye diagrams are obtained at 4.25 Gbps for both the Tx and Rx modes.
