New technologies to replace optical modules

Emerging technologies like Co-Packaged Optics (CPO), Linear-drive Pluggable Optics (LPO), Near-Package Optics (NPO), and silicon photonics (SiPh) are poised to complement or replace traditional pluggable optical modules in high-speed data centers.

Co-Packaged Optics (CPO)

CPO integrates optical components such as photonic integrated circuits (PICs) and lasers directly alongside switching ASICs or processors within the same package. This reduces electrical I/O distance, lowers power consumption, improves signal integrity, and increases bandwidth density compared to traditional pluggable modules. CPO is particularly suited for AI data centers where massive data exchange between GPUs, switches, and memory systems demands high efficiency and low latency. While CPO is not expected to immediately replace pluggable modules, it represents a fundamental shift toward chip-level optical integration and is likely to coexist with traditional modules in the near term .

Linear-drive Pluggable Optics (LPO)

LPO removes digital signal processors (DSPs) and clock data recovery circuits from the module, creating a purely analog "linear direct-drive" optical link. The transmitter directly drives the optical modulator, and the receiver uses a high-linearity transimpedance amplifier (TIA) for photoelectric conversion. LPO offers lower power consumption and reduced latency, making it suitable for closed-system AI and HPC deployments. However, it currently faces challenges in error correction, transmission distance, and multi-vendor compatibility .

Near-Package Optics (NPO)

NPO places the optical engine and processing chip (GPU, NPU, or switch) side-by-side on the same high-performance PCB or substrate, with a very short electrical path. This minimizes signal loss and crosstalk, supports high bandwidth (800G and above), and allows independent thermal management. NPO provides a middle ground between traditional pluggable modules and fully integrated CPO, offering high performance while maintaining easier maintenance and replaceability .

Silicon Photonics (SiPh)

SiPh integrates optical components onto silicon substrates using CMOS manufacturing processes. It enables high-density integration, improved power efficiency, and cost reduction. SiPh is foundational for LPO and other advanced optical interconnects, allowing compact transceivers that handle high data rates without external retiming circuitry. Technologies like Mach-Zehnder modulators enhance linearity and signal integrity, critical for high-speed analog optical links .

Summary

These technologies—CPO, LPO, NPO, and SiPh—address the limitations of traditional pluggable optical modules, including power consumption, thermal management, and bandwidth density. While pluggable modules remain relevant, especially for flexible and multi-vendor environments, these emerging solutions are key enablers for next-generation AI, HPC, and hyperscale data center architectures .