Temporal coherent control of superfluorescent pulses

Area of Science:

• Atomic physics
• Quantum optics
• Laser spectroscopy

Background:

• Superfluorescence (SF) is a coherent, light-induced emission from an ensemble of excited atoms.
• Investigating collective atomic phenomena requires precise control over atomic excitation and emission.
• Understanding quantum interferences is crucial for developing advanced optical technologies.

Purpose of the Study:

• To demonstrate that collective atomic interferences can be studied by measuring superfluorescence time delay.
• To explore the influence of controlled excitation parameters on superfluorescence characteristics.

Main Methods:

• Coherent excitation of rubidium (Rb) atoms using a pair of ultrashort, broadband laser pulses with variable delay.
• Measurement of superfluorescent pulses at 420 nm using a picosecond streak camera.
• Analysis of superfluorescence intensity and time delay as a function of input pulse delay.

Main Results:

• Both the intensity and time delay of the 420 nm superfluorescence pulse were significantly altered by varying the input pulse delay.
• The normalized 420 nm superfluorescence time delay exhibited oscillations with multiple periods.
• Observed phenomena were attributed to atomic and quantum interferences from two-photon excitation pathways.

Conclusions:

• Superfluorescence time delay is a sensitive probe for investigating collective atomic interferences.
• Quantum interference effects in two-photon excitation pathways influence superfluorescence dynamics.
• This method offers a novel approach to studying fundamental quantum phenomena in atomic systems.