Electrode Placement for Active Tuning of Silicon-on-Insulator (SOI) Ring Resonator Structure Clad in Nematic Liquid Crystals.

摘要

This technical report analyzes the optimum electrode placement for electrically tunable ring resonators. Combining these resonators with nematic liquid crystals enables easily tunable devices where the tuning is performed through either electrical or optical means. Electrode placement determines the total amount of a resonance shift that can be achieved. Simulation results contained within this report were performed using COMSOL Multiphysics(registered trademark) for a 500-nm wide, 250-nm tall silicon waveguide surrounded by SiO2 and liquid crystals. The 500-nm wide waveguide confines most of the optical mode to its core. The effect of electrode placement for electrically tunable ring resonators was analyzed. The symmetric ring resonator geometry plays a role in the total amount of achievable resonance shift. Factors governing the overall amount of resonance shift include the perimeter of the ring, the amount of the ring covered by SiO2, and the waveguide propagation loss influenced by the location of the metal layer above the buried oxide (BOX).