Coherent Amplification of Continuous Laser Field via Superfluorescence

Area of Science:

• Quantum optics
• Atomic, molecular, and optical physics

Background:

• Superfluorescence (SF) is a quantum optical phenomenon involving collective spontaneous emission.
• The emission process is initiated by the first photon, leading to synchronized, intense single-pulse emission.
• A key challenge in SF is the stochastic nature of the process, resulting in random shot-to-shot phase variations.

Purpose of the Study:

• To demonstrate control over the absolute phase of superfluorescence.
• To investigate the effect of seeding SF with a resonant continuous-wave (CW) laser.
• To explore the potential for coherent amplification in seeded SF.

Main Methods:

• Seeding the SF process with a weak resonant CW laser below the stimulated emission threshold.
• Utilizing cross-correlation measurements to analyze the interaction between the seeded SF and the CW laser.
• Quantifying the amplification factor of the seed light by the SF.

Main Results:

• Successful control of the SF absolute phase was achieved through CW laser seeding.
• The seed light was found to be coherently amplified by the SF emission.
• An amplification factor of 7 orders of magnitude for instantaneous intensity was measured.

Conclusions:

• Seeding provides a method to control the phase of superfluorescence, overcoming its inherent stochasticity.
• Coherent amplification of weak seed light by SF demonstrates a novel quantum optical effect.
• These findings offer a foundation for developing advanced quantum optical amplifiers and related technologies.