Y Torii, N Shiokawa, Y Matsuo, T Hirano, T Kuga
PROGRESS IN CRYSTAL GROWTH AND CHARACTERIZATION OF MATERIALS, 33(1-3) 413-417, 1996
We investigate spectroscopic properties of cold Rb-85 atoms in a magneto-optic trap. Both the transmission and the reflection spectra of the trapped atoms are recorded. The dressed-atom picture and the density-matrix formalism are appropriatery used to explain the absorption profile around the F = 3-F' = 2,3,4 and F = 2-F' = 1 transitions. Around the trapping laser frequency, phase-conjugation signals are observed (reflectivity is about 10(-4)), which are attributed to the degenerate and nearly-degenerate four-wave mixing.