Silicon photonics (SiPh) modules using DML are generally available for short-reach applications, but delivery times can vary depending on demand and supply constraints, with high-speed AI data center deployments potentially facing lead times of several months.

Current Availability and Lead Times

Silicon photonics technology integrates optical and electronic components on a single silicon chip, leveraging CMOS manufacturing processes. This allows for faster production scaling and lower costs compared to traditional EML-based modules, especially for 400G and above optical transceivers . DML (Directly Modulated Laser) is typically used for short-reach links (≤10 km) and is cost-effective, making it suitable for high-volume data center deployments . However, the delivery time for DML-based SiPh modules depends on several factors:

• High demand from AI and hyperscale data centers has increased pressure on optical module supply chains, particularly for EML lasers, which are constrained and expensive .
• SiPh modules using DML are less affected by EML shortages because they rely on external CW lasers, which are easier to source and manufacture at scale .
• Typical lead times for standard SiPh modules can range from a few weeks to several months, depending on order volume, customization, and supplier capacity. For high-volume AI deployments, some modules may have delivery timelines extending into late 2026 due to global demand .

Comparison with EML and CW Lasers

• DML + SiPh: Best for short-reach, high-volume applications; lower cost and faster to produce than EML-based modules.
• EML: Preferred for long-reach or high-performance PAM4 links; currently experiencing supply bottlenecks, leading to delivery delays beyond 2027 for some high-speed modules .
• CW + SiPh: Scales efficiently for high-density, high-speed optics (400G → 1.6T+), with multiple suppliers and shorter lead times compared to EML .

Practical Implications

For organizations planning 400G or 800G deployments:

• Short-reach links (≤10 km): DML-based SiPh modules are a reliable choice with moderate lead times.
• Medium to long-reach links (>10 km): Consider CW + SiPh or EML, but factor in potential delays due to EML supply constraints.
• High-volume AI data centers: Early engagement with suppliers is recommended to secure delivery slots and avoid extended lead times . In summary, DML-based silicon photonics modules are generally available and scalable, but delivery times can vary based on order size, customization, and market demand. For short-reach applications, they offer a cost-effective and faster-to-deliver solution compared to EML, while CW + SiPh is the preferred path for high-density, high-speed deployments.