Editing Openai/69109937-2170-8005-9304-da49840bb5b9 (section)

==== - You are right to zoom in on coupling efficiency — it’s one of the few technical parameters that can really kill the promised cost advantage if it is off by even 1–2 dB. ====
* Based on public info, POET’s claimed coupling performance is compatible with high-end 400G/800G specs, and their interposer architecture is explicitly optimized for low-loss passive alignment.
* The old rule of thumb “active = better efficiency, passive = cheaper” is too crude here: - For ad-hoc geometries, still true. - For purpose-designed interposer platforms, passive can be almost as good on efficiency and vastly better on cost/throughput.

If you like, next step could be to build a simple link-budget comparison:
* Plug in reasonable per-interface losses for an “old-school” actively aligned TOSA vs a POET-style interposer engine and see how much margin and power you gain/lose in each case. That often makes the trade-offs painfully clear.