Demonstration of fully enabled data center subsystem with embedded optical interconnect

Pitwon, Richard; Worrall, Alex; Stevens, Paul L; Miller, Allen; Wang, Kai; Schmidtke, Katharine

doi:10.1117/12.2039865

Cited by 9 publications

(7 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Various technologies are being developed for use at the different interconnection levels: board-to-board, chip-to-chip and on-chip. Technological approaches to date have included using free-space [3], [4], fibre-based [5], [6], III-V and Si photonics [7], [8] and polymer-based interconnects [9], [10]. In particular, multimode polymer waveguides are promising for use in board-level optical interconnections as such waveguides exhibit excellent optical properties [11] and can be cost-effectively and directly integrated on standard printed circuit boards (PCBs).…”

Section: Introductionmentioning

confidence: 99%

Flexible Multimode Polymer Waveguide Arrays for Versatile High-Speed Short-Reach Communication Links

Shi

Bamiedakis

Vasil'ev

et al. 2018

J. Lightwave Technol.

View full text Add to dashboard Cite

Optical interconnects play an important role in enabling high-speed short-reach communication links within nextgeneration high-performance electronic systems. Multimode polymer waveguides in particular allow the formation of high-capacity optical backplanes and cost-effective board-level optical interconnects. Their formation on flexible substrates offers significant practical advantages and enables their deployment in environments where shape and weight conformity become particularly important, such as in cars and aircraft. However, bending and twisting of flexible multimode waveguides can have a significant effect on their optical transmission performance due to mode loss and mode coupling. Moreover, the magnitude of the induced effects strongly depends on the launch conditions employed. In this paper, therefore, we present detailed loss, crosstalk, and bandwidth studies on flexible multimode waveguide arrays for different launch conditions regarding their use in real-world systems. The minimum radius to achieve a 1 dB excess bending loss is obtained for each launch condition as well as the crosstalk degradation due to bending. It is shown that for a 50 µm MMF input, a 6 mm bending radius is required for excess losses below 1 dB, while crosstalk below −35 dB is obtained in adjacent waveguides even under strong bending. Moreover, it is found that twisting has a small effect on the loss and crosstalk performance of the samples. Excess twisting loss less than 0.1 dB and crosstalk of −40 dB are obtained for three full 360°turns under a 50 µm MMF launch. Finally, the bandwidth studies carried out on the samples indicate than no significant bandwidth degradation is induced due to sample bending, with bandwidth-length product values larger than 150 GHz × m obtained for restricted launches. The set of results presented herein specify the deployment of this flexible polymer multimode waveguide technology in real-world systems and demonstrate its strong potential to implement low-loss highbandwidth optical interconnects.

show abstract

Section: Introductionmentioning

confidence: 99%

Flexible Multimode Polymer Waveguide Arrays for Versatile High-Speed Short-Reach Communication Links

Shi

Bamiedakis

Vasil'ev

et al. 2018

J. Lightwave Technol.

View full text Add to dashboard Cite

show abstract

“…Embedded optical engines with several lane wide (x4, x8, x12, x16) and data rate (up to 28 Gbps per lane) and FPGA packages (up to 28Gbps) with optical pigtail connectors are available in the market with multiple vendors 4 . Moreover, fiber-optic sheets, polymers waveguides and glass waveguides are in development [5][6][7][8][9][10][11] . Optical links need to provide low absorption at the wavelength of interest; low modal dispersion and they need to match optical connector densities with low coupling loss and cross-talk.…”

Section: Introductionmentioning

confidence: 99%

Electro-optical line cards with multimode polymer waveguides for chip-to-chip interconnects

Zhu¹,

Immonen²,

Wu³

et al. 2014

SPIE Proceedings

View full text Add to dashboard Cite

In this paper, we report developments of electro-optical PCBs (EO-PCB) with low-loss (<0.05dB/cm) polymer waveguides. Our results shows successful fabrication of complex waveguide structures part of hybrid EO-PCBs utilizing production scale process on standard board panels. Test patterns include 90° bends of varying radii (40mm -2mm), waveguide crossing with varied crossing angles (90°-20°), cascaded bends with varying radii, splitters and tapered waveguides. Full ranges of geometric configurations are required to meet practical optical routing functions and layouts. Moreover, we report results obtained to realize structures to integrate optical connectors with waveguides. Experimental results are shown for MT in-plane and 90° out-of-plane optical connectors realized with coupling loss < 2dB and < 2.5 dB, respectively. These connectors are crucial to realize efficient light coupling from/to TX/RX chip-to-waveguide and within waveguide-to-fiber connections in practical optical PCBs. Furthermore, we show results for fabricating electrical interconnect structures e.g. tracing layers, vias, plated vias top/bottom and through optical layers. Process compatibility with accepted practices and production scale up for high volumes are key concerns to meet the yield target and cost efficiency. Results include waveguide characterization, transmission loss, misalignment tolerance, and effect of lamination. Critical link metrics are reported.

show abstract

“…ThunderValley2 is a fully optically enabled data storage array that was developed based on a 2U24 OneStor enclosure from Seagate Technology, in which all internal highspeed links were implemented optically. This required the deployment of commercial midboard optical transceivers, an electro-optical midplane and proprietary pluggable optical connectors for hard disk drives [5].…”

Section: Introductionmentioning

confidence: 99%

Evolution of System Embedded Optical Interconnect in Sub-Top-of-Rack Data Center Systems

et al. 2022

Self Cite

View full text Add to dashboard Cite

In this paper we review key technological milestones in system embedded optical interconnects in data centers that have been achieved between 2014 and 2020 on major European Union research and development projects. This includes the development of proprietary optically enabled data storage and switch systems and optically enabled data storage and compute subsystems. We report on four optically enabled data center system demonstrators: LightningValley, ThunderValley2, Pegasus and Aurora, which include advanced optical circuits based on polymer waveguides and fibers and proprietary electro-optical connectors. We also report on optically enabled subsystems including Ethernet-connected hard disk drives and microservers. Both are designed in the same pluggable carrier form factor and with embedded optical transceiver and connector interfaces, thus allowing, for the first time, both compute and storage nodes to be optically interchangeable and directly interconnectable over long distances. Finally, we present the Nexus platform, which allows different optically enabled data center test systems and subsystems to be interconnected and comparatively characterized within a data center test environment.

show abstract

Demonstration of fully enabled data center subsystem with embedded optical interconnect

Cited by 9 publications

References 4 publications

Flexible Multimode Polymer Waveguide Arrays for Versatile High-Speed Short-Reach Communication Links

Flexible Multimode Polymer Waveguide Arrays for Versatile High-Speed Short-Reach Communication Links

Electro-optical line cards with multimode polymer waveguides for chip-to-chip interconnects

Evolution of System Embedded Optical Interconnect in Sub-Top-of-Rack Data Center Systems

Contact Info

Product

Resources

About