Numerical and Experimental Analysis of On-Chip Optical Wireless Links in Presence of Obstacles

In this work, we analyze the effects of the presence of waveguides in a wireless on-chip optical channel, which act as obstacles for the rays composing the propagating signal. The analysis has been performed numerically by using the FDTD method, and the simulation results have been validated by the experimental characterization. This work focuses on the relationship between the received signal and the position of the obstacles on the circuit plane in a multilayered channel made of heterogeneous dielectric cladding. We show how the crossing waveguide perturbates the received power and we provide ad hoc guidelines for the best topological choices allowing to mitigate losses. Moreover, with a good agreement between numerical and experimental results, amounting to a variation of less than 1 dB, we have demonstrated that the effects of this perturbation in real chips can be predicted. The results of this analysis, as well as increasing the level of knowledge of on-chip optical wireless links, allow a better comprehension and control of unbound optical signals within the optical chip environment.