// Coherent Optics
DWDM Open Line System Optical Networking 400ZR 400ZR+ Alien Wavelength Disaggregated ROADM EDFA Coherent Optics TIP Goldstone Hyperscale Network Architecture OSNR Spectrum Management

Open Line Systems — Breaking the DWDM Vendor Lock

Your DWDM line system and your transponders come from the same vendor. The amplifiers, the mux/demux, the management plane, the optics. One PO, one support contract, one vendor'

Rene Fichtmueller / 2026-05-01 / ~4 min read min read
Silicon Photonics Indium Phosphide Optical Networking SiPh InP Photonic Integrated Circuit CMOS Coherent Optics Supply Chain Intel Cisco Lumentum Coherent Corp Foundry Semiconductor

Silicon Photonics vs Indium Phosphide — The Foundry War Behind Your Optics

Two materials. Two manufacturing ecosystems. Two different bets on the future of optical networking. The choice between Silicon Photonics and Indium Phosphide determines who can build your optics, how fast,

Rene Fichtmueller / 2026-04-30 / ~3 min read min read
400G Firmware CMIS QSFP-DD EEPROM DSP Optical Transceiver Troubleshooting Network Engineering State Machine Optics Compatibility DataPathActivated Coherent Optics Flexbox Programmer Optical Networking

Firmware Hell — Why Your Optics Break After Upgrade

A system runs stable for months, then starts showing intermittent link resets after a routine update. Nothing is technically broken. The system behavior has changed.

Rene Fichtmueller / 2026-04-14 / ~3 min read min read
400G 400ZR 400ZR+ Coherent Optics QSFP-DD OSFP DWDM Optical Networking Data Center Network Design Supply Chain Capacity Planning Lead Time DP-16QAM Indium Phosphide Optical Transceiver ECMP

Coherent 400G ZR+ — When Lead Time Becomes a Design Problem

The design is complete. Procurement comes back: 400ZR+ optics are not available for four to five months. That is not a supply chain problem. It is a design assumption problem.

Rene Fichtmueller / 2026-04-13 / ~3 min read min read