In the field of high-speed optical interconnect, CPO, NPO, LPO, and OCS represent different technologies or packaging forms. The following is a detailed introduction to each of them:
CPO (Co-Packaged Optics):
This is a new type of optoelectronic integration technology. By packaging the optical module and the switching chip closely together, it significantly reduces the distance signals travel during electrical-optical conversion and transmission. This substantially lowers power consumption, improves signal integrity, reduces latency, and decreases physical size. It is mainly used in front-end networks connecting data center servers.
NPO (Near-Packaged Optics):
This technology decouples the optical engine and the switch chip, then assembles them on the same system board. Compared to CPO, the modules in NPO are located farther from the host ASIC. CPO achieves lower channel loss and power consumption.
LPO (Linear Drive Pluggable Optics):
This is an optical module packaging technology that replaces traditional DSPs with linear drive technology, achieving advantages in system power reduction and lower latency, but at the cost of system bit error rate and transmission distance. It eliminates the Digital Signal Processor (DSP) by using Trans-Impedance Amplifiers (TIA) and driver chips with excellent linearity and equalization capabilities to replace the DSP, removing the need for signal re-timing and reducing processing overhead and system latency. It is particularly suitable for GPU communication scenarios in High-Performance Computing (HPC) centers with extremely high timing requirements.
OCS (Optical Circuit Switching):
An all-optical switching device that establishes end-to-end physical connections directly in the optical domain, without any optical-electrical-optical (O-E-O) conversion throughout the entire process.
