Ultrafast optical switching utilizing coherent interaction is reviewed in terms of its principle, problems, applications and features in conjunction with the result of numerical calculations.
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.
We propose an optical memory cell based on ultrafast wavelength switching in coupled-cavity microlasers, featuring bistability between modes separated by several nanometers. A numerical implementation is demonstrated by simulating a two-dimensional photonic crystal microlaser. Switching times of less than 10 ps, switching energy around 15-30 fJ, and on-off contrast of more than 40 dB are achieved. Theoretical guidelines for optimizing the performance of the memory cell in terms of switching time and energy are drawn.