Once the laser is moved off the chip, someone has to catch that +20 dBm high-power light. AIST shows that polymer waveguides on low-cost glass-epoxy substrates can do it: zero degradation over six hours and only a 4.4°C temperature rise — a key feasibility endorsement for the packaging-centric CPO route.

Keio University's "Mosquito method" draws light paths into polymer with a single needle, using a graded-index core to avoid interface scattering for near-material-limit loss — and uses fluid dynamics to beat the needle-size limit for 20 µm pitch. What is the open question for the polymer waveguide route?

CPO volume production is held back by micro-lens pick-and-place and active alignment. AIST turns the lens-mirror into an opto-chiplet embedded during molding, routes light with an Optical RDL, and widens alignment tolerance to ±12 µm.

AIST × KYOCERA have lit up the long-shelved AOP concept for the first time: an embedded SiPh chip, polymer ORDL and 3D micro-mirrors deliver 112 Gbps PAM4 with 3.35 dB TDECQ, passing IEEE specs. How far has the polymer optical-redistribution route come?

Qnity builds optical waveguides into the PCB process with BCB dry film: the lowest adoption barrier, 0.07–0.11 dB/cm loss, and it survives reflow and high temperature/high humidity. It also honestly debunks the common assumption that widely spaced multimode waveguides don't crosstalk. Where is the sweet spot for board-level optical interconnect?

DNP brought polymer waveguides on glass down to a 10 µm pitch, but the real point is an iron rule: density is paid for with index contrast. Only Δ=2.3% pushes 10 µm crosstalk down to −32.3 dB. Which three material parameters decide whether polymer waveguides can compete?

KYOCERA breaks low-loss coupling for CPO modules into three parts: face-down cooling, a curved mirror and a wide-tolerance core. Coupling loss halved to 1.22 dB, ±5 µm tolerance, error-free from 0 to 70°C. Why can't you judge a coupling module by a single loss number?