Ultrafast, Compact, and Energy Efficient All-Optical Switches Based on a Saturable Absorbing Cavity

In this paper, we propose and theoretically investigate an ultrafast, compact, and energy efficient all-optical switch (AOS) design based on a saturable absorbing cavity. The conceptual basis of the switch design is the material absorption saturation phenomenon. The optical cavity is used to enhance the light-matter interaction locally. As a result, the device dimension is substantially reduced. Numerical studies were carried out analytically using the temporal-coupled mode theory. Cavity structural parameters and material properties related to the switch design are discussed. The figure of merit of the switch performance in terms of the insertion loss, extinction ratio, and operating energy consumption are analyzed. Finally, as a specific practical application of the developed AOS, ultrahigh-speed optical time division multiplexing operations are demonstrated.