| All-optical switches have far reaching applications in both quantum and classical information processing. Most current all-optical switches depend on intense interactions between light and nonlinear media which may be extremely inefficient. The need for high switching beam powers have prevented all-optical switching from being very useful in most applications. Our research has been primarily aimed at increasing the strength of interactions between light and matter to produce more efficient switches. We have studied several different types of all-optical switches in atomic media. Our methods employ optical resonators and tapered optical nano-fibers which increase the intensity of the switching beam, thereby increasing the interaction strength.;The switching experiments discussed here are performed in Rubidium 85 atoms. One method for switching makes use of cold atoms in a magneto optical trap. Since trapped atoms can have very narrow resonance linewidths, it will be shown that switches in cold atoms can operate at extremely low input powers. Another type of switching is performed in hot Rubidium vapor. Due to Doppler broadening and transit time effects these atoms have a significantly larger resonance linewidth. This can produce broadband high speed switching, at the expense of having to increase, somewhat, the input power. |
