Wavelength Multiplexing Is the Way to Scale Optical Bandwidth

Scintil Photonics CEO Matt Crowley argues that optical scale-up must be multiplexed, favoring wavelength scaling over higher symbol rates.

• Main announcement: Matt Crowley makes the case that scale-up networks should prioritize wavelength multiplexing (multiply channels) rather than increasing symbol rates; specific recommended parameters include ~50 gigabits per second per channel using NRZ encoding, with examples of 4 → 8 → 16 wavelengths delivering 200 → 400 → 800 Gbps (the article uses 8×50Gbps = 400Gbps and 16×50Gbps = 800Gbps) per fiber. The piece frames four wavelengths as a production floor, with higher counts multiplying capacity on the same fiber plant.
• Background and details: The article contrasts wavelength scaling with faster symbol-rate approaches (e.g., NRZ → PAM-4 tradeoffs), noting higher symbol rates raise power, latency, signal processing, and heat costs across GPU clusters; it highlights heterogeneous integration (bonding lasers onto silicon photonics wafers) as the manufacturing path that lets additional wavelengths follow a compounding cost curve. The post also references a forthcoming capstone covering the OCI MSA and manufacturing implications.