We investigate superfluorescence (SF) in a degenerate system, where two polarization modes of SF were emitted in competition with each other. A circularly polarized femtosecond laser pulse is used to excite Rb atoms in a heated gas cell from the $5S$ ground to $6P$ state, followed by the SF decay process $6P\to 6S\to 5P\to 5S$. Because the $6S$ and $5P$ levels degenerate into two and four states, respectively, four degenerate transitions are optically allowed between the two levels. Therefore, the left- or right-circularly polarized SF is emitted with a relative intensity determined by the Clebsch-Gordan coefficients of all degenerate transitions. We investigate the polarization characteristics of all SF fields emitted during the decay process. Furthermore, we demonstrate the possibility of switching the dominant polarization component of the SF on the $6S\to 5P$ transition by seeding it with a weak resonant circularly polarized continuous laser field.

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• Atomic & molecular processes in external fields
• Collective effects in atomic physics
• Spontaneous emission