KU Leuven showed a plastic waveguide (above) running at 120GHz sending 2.5 Gbits/s at seven meters and 12.7 Gbits at a meter. The flexible link allows manual alignment making it easier and cheaper than optical fibre.
Fujitsu Labs demonstrated the prototype silicon photonics running at 25 Gbits/s below.
Next Page: Heads up display and brain monitor
What I saw at ISSCC 2015: