Low power 7.2 Terabit Transmitter for Exascale Computing

Exascale computing for Large-Scale Numerical Simulation requires a new technology for optical communication. VCSEL based transmitters run out of bandwidth at 56 Gbps PAM4, and the latency of PAM4 is incompatible with exascale computing. Other available technologies are excessively expensive, have high power consumption, are far from proven or they require temperature control. Our proposed concept integrates an Electro-Absorption Modulator (EAM) with a Surface-Emitting (SE) laser capable of > 100 Gbps/channel NRZ which can be arrayed to > 1.2 Tbps for a 12 element array and using Course Wavelength Division Multiplexing (CWDM) with 6 wavelengths can reach > 7 Tbps. Using NRZ instead of a more complex format reduces latency dramatically. The proposed device can operate over a wide temperature range, at least 25C to 100C and potentially over the full military range (-55C to 125C) without temperature control. The SE Laser-EAM has a 50% (0.3 pJ/bit vs 0.6 pJ/bit) reduction in power per bit compared to VCSEL solutions, and the transmission distance is dramatically improved. The proposed low cost device can be manufactured by the billions. The SE Laser-EAM array can be flip-chip mounted onto silicon. This unique device has ten times the reach of VCSELs, more than sufficient for any data center or exascale computer. The SE Laser-EAM is made from elements which are already proven and understood, but put together in a manner which achieves the performance exascale computing needs. In the final product a driver circuit will be integrated with the SE Laser-EAM array along with the CWDM optics to create a 7.2 Tbps transmitter module. More »