Cascadable planar-integrated fan-out module for parallel free-space optical short-haul interconnects

We report about design, fabrication, and test of a cascadable planar-integrated free-space optical fan-out module that can be used in an optical cross-connect switch for short-haul interconnects. For a 1 x 4 fan-out a coupling efficiency of -11.4 dB per channel was obtained.