Observation of arbitrary group velocities of light from superluminal to subluminal on a single atomic transition line
- Department of Physics Education, Korea National University of Education, Chung-buk, 363-791, Korea (Korea, Republic of)
We were able to arbitrarily control the speed of a light pulse from subluminal to superluminal velocity by changing only the power of the laser for coupling coherently the single transition between 6 {sup 2}S{sub 1/2}F=4 and 6 {sup 2}P{sub 3/2}F{sup '}=5 in the D{sub 2} line of a Cs atomic vapor system. With weak coupling power, a Gaussian light pulse was propagated superluminally with a negative group velocity v{sub g}=-c/14 400, which is caused by a highly anomalous dispersion related to an electromagnetically induced absorption. By increasing the coupling power at the same laser frequency, the pulses were propagated with a vacuum speed at the middle power and a subluminal group velocity v{sub g}=c/3000 at high power, which is caused by a normal dispersion related to an electromagnetically induced transparency. It was also found that group velocities depend largely on polarization combinations.
- OSTI ID:
- 20639961
- Journal Information:
- Physical Review. A, Vol. 68, Issue 1; Other Information: DOI: 10.1103/PhysRevA.68.013810; (c) 2003 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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