Slow light, fast light, and their applications

Robert W. Boyd, Nikolay N. Lepeshkin, Aaron Schweinsberg +1 more

Thomas Zacharias, Liran Hareli, Alon Bahabad

Abstract Slow and fast light are light pulses moving at group velocities slower or faster than the speed of light in vacuum. Current methods to achieve slow and fast light are based on strong dispersion attainable in resonant systems. By defining slow and fast light based on the arrival of the expectation value of the pulse in time, an alternative route for achieving slow and fast light is experimentally demonstrated where no dispersion engineering is needed and thus can be applicable to any medium and system where light is propagating. The method is based on the phenomenon of superoscillations and entails a weak measurement of the arrival time of a light pulse. The findings can be useful for applications in telecommunication, interferometry, and laser radars.

Bin Luo, Hong Mei Guo

Dispersion properties of an optical medium can be greatly changed using electromagnetically induced transparency (EIT) and other nonlinear effects. Thus, the group velocity of light pulse can be much smaller (greater or even negative) than light speed in vacuum, which is called slow (fast) light. Slow and fast light are very useful in optical processing, such as optical buffer, switching, and storage devices. Usually, slow and fast light cannot be generated simultaneously in the same medium. In this paper, we propose applicable level structures to generate controllable slow and fast light simultaneously at two frequencies, with the same polarization.