System robust optimization of ring resonator-based optical filters

Fabrication variations can have a detrimental effect on the performance of optical filters based on ring resonators. However, by using robust optimization these effects can be minimized and device yield can be significantly improved. This paper presents an efficient robust optimization technique for designing manufacturable optical filters based on serial ring resonators. The serial ring resonator is treated as a system which has computationally expensive (directional coupler section) and cheap components (ring section). Cheap mathematical models are constructed of the directional coupler sections in the resonators. The approximate system response based on the cheap model is then robustly optimized. The robust bandpass filter performance is compared against designs that do not take uncertainties into account. The optimality of the robust solutions is confirmed by simulating it on the expensive physical model as a post-processing step. Results indicate that the employed approach can provide an efficient means for robust optimization of ring resonator-based optical filters.