Why it s not recommended to buy optical modules

Buying traditional optical modules is increasingly risky due to supply chain fragility, reliability issues, and the industry shift toward co-packaged optics (CPO) and silicon photonics.

Supply Chain and Reliability Concerns

Optical modules are highly sensitive components, and even small variations in manufacturing can lead to failures. For example, a hyperscale network operator found that 12% of 400G DR4 modules failed within 90 days due to a change in laser bonding adhesive, which caused lens clouding under heat, despite passing standard compliance tests. Batch-to-batch variations in VCSEL bandwidth, DSP equalizer settings, and PCB surface finish can bypass standard qualification, creating hidden reliability risks.

Modules may pass lab tests but fail under real-world thermal and network conditions, leading to increased bit error rates and reduced system performance.

Technological Obsolescence

The optical module market is being disrupted by co-packaged optics (CPO) and silicon photonics. Companies like Nvidia are embedding optical engines directly into ASIC switch packages, eliminating the need for traditional pluggable modules. This integration reduces costs, improves energy efficiency, and increases reliability, but it also renders standalone optical modules less relevant.

As a result, the market for conventional modules is shrinking, and suppliers may be squeezed out, making future support and availability uncertain.

Cost and Maintenance Implications

Traditional optical modules are expensive, often costing $600–$2000 each, with a significant portion of the price being supplier markup.

With CP

O, the optical portion is integrated, eliminating housing, connectors, and DSP retimers, which reduces costs and centralizes control. Additionally, servicing CPO systems is more complex; failures require removing or replacing the entire switch, whereas pluggable modules can be swapped easily. This makes investing in traditional modules less cost-effective in the long term.

Market and Supply Constraints

The rapid growth of AI infrastructure has created a bottleneck in optical module supply, particularly for high-speed lasers like EMLs. Lead times are extended, and strategic customers often pre-allocate capacity, making it difficult to secure modules for large-scale deployments. This scarcity, combined with the shift to integrated optics, increases the risk of investing in modules that may soon be obsolete or hard to source.

Conclusion

Purchasing traditional optical modules is not recommended due to high failure risk, supply chain fragility, escalating costs, and impending obsolescence driven by the transition to CPO and silicon photonics. Organizations planning for AI or hyperscale data center deployments should consider integrated optical solutions or closely monitor the evolving market to avoid stranded investments.