Tolerance Analysis for Multilayer Optical Interconnections Integrated on a Printed Circuit Board

Polymer multilayer optical interconnections have gained interest over the past few years in view of their ability to increase the integration density, increase the routing flexibility, and make full use of the characteristics of 2D optoelectronic elements. The alignment between the functional elements in the different optical layers has to be sufficiently accurate in ensuring a high overall efficiency of the system. Numerical simulations have been used as a tool to determine whether laser ablation can be used as an alternative technology for the structuring of the functional elements of optical interconnections into a polymer optical layer. The experimentally achievable alignment accuracies are compared to tolerance ranges for an excess loss ¿ 1 dB obtained from the numerical study. The experimental achievements show that the alignment accuracies fall within the numerical tolerance ranges and have a good reproducibility. Experimental realizations of a two-layer multimode waveguide and inter- and out-of-plane- coupling structures are discussed and shown.