Dynamics of a Photochromic-Actuated Slot Microring Photonic Memristor

In electronic circuits, memristors have been defined as resistors whose resistance depends on past signals. Such elements have promise as low-power weighting and self-learning elements in electronic neuromorphic circuits. Photonic memristors, elements whose transmission depends on past optical signals, are experiencing renewed study alongside the rise in interest in neuromorphic photonics. One potential route to creating photonic memristors involves incorporating photochromic materials, whose optical properties continuously change with optical illumination, into photonic integrated circuits (PICs). In this manuscript we lay out a theoretical model to study the transmission dynamics of devices incorporating photochromic compounds into SiN planar microring resonators which utilize slot waveguide structure, and show that such devices fulfill the criteria for memristive behaviour. This represents a practical path towards incorporating photonic memristors into a technologically mature material platform with minimal additional fabrication processes.