Perturbation Theory for Thin Cladding Layers on Silicon Photonic Systems
I develop a perturbation theory for resonant frequency shifts caused by thin layer of material added to dielectric systems. This development can be used to effectively model photonic surface-sensing systems, which use this resonance shift to measure the presence of, e.g., biomolecules attached to the sensor system. Direct modeling was previously intractable due to extremely long simulation times required to account for the cladding layers. The developed theory is verified against a special-case direct simulation and by measuring the shift caused by silicon dioxide deposited on a fabricated ring-resonator sensor.