TeraHop: 800G Coherent Lite LR2

TeraHop’s 800G Coherent Lite LR2 is optimized for 10–40 km metro and short-reach data center interconnection (DCI) applications. By streamlining the DSP pipeline and removing long-haul–oriented processing blocks—such as advanced nonlinear compensation and heavy long-reach FEC mechanisms—the solution achieves a carefully balanced trade-off between performance, power efficiency, and system cost. The module integrates a silicon-photonics-based coherent PIC, enabling higher optical integration and stability. At the system level, the coherent Lite DSP employs an optimized dispersion-compensation strategy and a simplified MIMO equalization flow, providing adequate link margin for 800G transmission while maintaining substantially lower power consumption than full-featured coherent implementations. The reduced complexity also minimizes electrical interface requirements, power-delivery constraints, thermal load, and packaging overhead, making LR2 particularly suitable for high-density, power-sensitive DCI and cloud-edge deployments. 

Judge’s comment: “Coherent Lite will become the technology for campus-scale DC interconnect (up to 40 km) at a lower cost and power consumption than full coherent communication.”