Bandwidth of the optical module

Current optical modules can achieve bandwidths up to 512 Gbps, with standard high-performance modules commonly supporting 400 Gbps.

Overview of Optical Module Bandwidth

Optical modules, also known as pluggable transceivers, convert electrical signals into optical signals and vice versa, enabling high-speed data transmission over fiber networks. Their maximum bandwidth depends on factors such as the number of lanes, modulation techniques, and the form factor of the module .

Standard High-Bandwidth Modules

• 400G Optical Modules: Widely deployed in hyperscale data centers, these modules typically use PAM4 (4-Level Pulse Amplitude Modulation) to double the data rate per channel. For example, a 400G SR4 module uses 4 channels at 100G each, achieving a total of 400 Gbps . Enhanced versions like the 400G SR4.2 can use 8 channels at 50G each, maintaining 400 Gbps while extending transmission distance .
• Form Factors: Common high-speed modules include QSFP-DD, OSFP, and SFP-DD, which support multiple lanes and high-density deployment .

Record-Breaking On-Board Optics

• Kyocera On-Board Optics Module: Achieves a world-record bandwidth of 512 Gbps by integrating optical conversion directly on the PCB near the processor. This design reduces signal loss and power consumption while enabling ultra-high-speed data transfer .

Factors Affecting Maximum Bandwidth

1. Lane Count: More lanes allow parallel transmission, increasing total bandwidth.
2. Modulation Technique: PAM4 doubles the data rate compared to traditional NRZ signaling.
3. Wavelength Division Multiplexing (WDM): Using multiple wavelengths per fiber can further increase effective bandwidth.
4. Fiber Type and Distance: Multimode fiber supports shorter distances at high speeds, while single-mode fiber enables longer reach with high bandwidth .

Future Trends

Research is ongoing to develop 1.6T and 3.2T optical modules, leveraging higher lane counts, advanced modulation, and improved optical interconnects to meet the growing demands of AI, 5G, and hyperscale data centers .

Summary

• Current commercial maximum: 400 Gbps (standard modules like QSFP-DD, OSFP)
• Experimental/on-board optics: 512 Gbps (Kyocera module)
• Emerging targets: 1.6T–3.2T modules for next-generation data centers
• Key enabling technologies: PAM4 modulation, multi-lane architecture, WDM, and advanced form factors . These advancements ensure that optical modules continue to scale bandwidth to meet the exponential growth in data communication demands.