Physical Mechanism and Response Characteristics of Unsaturated Optical Stopping-Based Amorphous Arsenic Sulfide Thin-Film Waveguides

Optical stopping can serve as a light-controlled solution to implementing photonic components. In contrast to saturated optical stopping that provides enough excited electrons to entirely absorb signal lights, unsaturated optical stopping introduces a photon competition mechanism for signal lights and pump lights due to insufficient excited electrons. This photon competition mechanism produces a kind of regular signals, which is very similar to the signals applied in pulse-coupled neural network. However, due to its unclear physical mechanism, it is impossible to further improve performances of the unsaturated optical stopping-based components. Here, we propose a kinetic model to reveal physical mechanism of the unsaturated optical stopping and establish a corresponding formalism that enables calculation of time response of the unsaturated optical stopping-based amorphous arsenic sulfide thin-film waveguides. Our work provides a new insight into the physical phenomenon of unsaturated optical stopping and builds a theoretical foundation for further research on response characteristics of amorphous arsenic sulfide thin-film waveguides.