Cost-effective waveguide integration method for large-scale electrical-opticalcircuit-board production

Based on KMnO₄ wet etching technology, a low-cost waveguide integration technique of polydimethysiloxane (PDMS) based electrical-optical-circuit-board (EOCB) with FR4 substrates was developed, which is quite suitable for large-scale EOCB production. The optical and mechanical properties of the PDMS waveguide layer remained unchanged before and after waveguide integration. The mechanical stability limit of the tested EOCBs is determined only by the intrinsic mechanical stability of the used PDMS materials. The optical waveguide propagation loss at 850 nm is less than 0.1 dB/cm after surviving the defined environmental test procedures.