Intellectual Merit. This research is aimed at developing improved methods for controlling the velocity with which light pulses propagate through material systems and at developing technologically important applications of these techniques. One of these applications is the development of interferometers with increased spectral sensitivity. Simple theoretical arguments show that the sensitivity of an interferometer can be increased by a factor as large as the group index of a material placed in one arm of the interferometer. In another study, fast-light techniques will be implemented to prevent the occurrence of laser damage in high-power laser systems. When a light pulse enters a material for which the group index is positive but smaller than unity, the pulse becomes stretched in space, and thus the energy density is lowered. This effect tends to suppress the occurrence of laser damage. Furthermore, studies will be performed of how the coherence properties of light beams are transformed on propagation through materials with extreme group velocities. A novel physical process for controlling the velocity of light will also be studied. This process involves the nonlinear response of the strongly driven two-level atom. In the presence of an intense laser field, the absorption spectrum of a two-level atom is strongly modified and is split into three components, each of which has properties that can be used to control the velocity of light. Both gain and absorption features are present, leading to both slow and fast light speeds, with modulation bandwidths as large as several GHz.
Broader Impact. The broader impact of the proposed activity includes the following: This work will be conducted by a research group consisting of students and post-doctoral scientists from diverse ethnic and cultural backgrounds. They are encouraged to work collaboratively and to explore the intellectual underpinnings of their research projects. In addition, the subject area of the proposed effort is one of great interest to the general public. Effort will be made at broadcasting the results of this research program to a community broader than the academic research community. In this manner, this project will strive to foster interest in science and engineering within the general public and especially among underrepresented minorities.
