Tunable ultraslow light propagation in ruby

Abstract

Ruby is one of the best solids for generation of slow light at room temperature. Ultraslow light propagation to ∼2.8 m/s has been demonstrated experimentally in ruby rod of length 7.6 cm. The systematic variation of optical delay with the modulation frequency, laser power and depth of focus has been studied. Fine tuning from ∼12 ms to ∼20 ms has been achieved by using laser power and depth of focus as a knob, at a modulation frequency of 1.8 Hz. These studies suggest that ruby rod may find potential applications in developing the tunable optical delay-based devices.