下一代光互连.pdf

1、Andreas Bechtolsheim,Arista NetworksPeng Mike Li,AlteraNext Generation Optical InterconnectsOptics Technology TransitionsTechnologyCurrent GenerationNext GenerationHigh-speed Serdes212.5G-PAM4425G-PAM4Modulator TechnologySilicon PhotonicsInP,TFLN,OrganicOSFP Module1600G(8x200G)3200G(8x400G)Form Fact

2、orOSFP(8 Lanes)High-density(64 Lanes)Key Topics for 425G/Lane OpticsOptics require PAM4 Modulation to achieve good OSNRThis means 106 GHz Channel Bandwidth at 425G/laneCPC Connectors(Co-packaged Copper)Best way to achieve a clean high bandwidth channel New Optics Modulator TechnologiesTraditional Si

3、licon Photonics out of bandwidth Benefit of 400G is 2X densification and significant cost-reduction Significant Cost Reduction with 3200G3200G-DR8DSP 3200G-DR8 Module 1600G-DR8 Module8x400G8x400G1600G-DR8DSP8x200G8x200G3200G(8x400G)optics have same number of parts(drivers,lasers,detectors,fibers,con

4、nectors)as 1600G optics(8x200G)400G IM/DD Technology ChoicesSource:LumentumFirst Product:1600G-DR4/FR4Disadvantage is high-power gearbox DSP1600G OSFP Module with 4x400G-PAM4 LambdaElectrical interface 8x200G-PAM4Gearbox DSP converts to 4x400G-PAM4EML,InP or TFLN OpticsFirst prototype demo at OFC 20

5、25Second Product:3200G-DR8/2FR4Needs new Connector for 425G-PAM4(106 GHz Nyquist)3200G Optics Module with 8x400G-PAM4 LambdaNeeds 400G Native SERDES switch chipsLinear or LRO/TRO InterfaceEML,InP or TFLN OpticsProduction expected in 2028Main Challenge is DSP PowerWatt01020304050800G 1600G 3200GLPOLR

6、ODSPpJ/Bit improves with 3200G,but power premium for DSP is steeppJ/Bit048121620800G 1600G 3200GLPOLRODSPOther Packaging ApproachesThermal challenge can be solved with liquid coolingHigher Channel Count Pluggable Modules64 channels 400G=25.6TReduces system electrical channel lengthJust 8 Modules for