Coherent control of superradiance from nitrogen ions pumped with femtosecond pulses

Abstract

Singly ionized nitrogen molecules in ambient air pumped by near-infrared femtosecond laser give rise to superradiant emission. Here we demonstrate coherent control of this superradiance by injecting a pair of resonant seeding pulses inside the nitrogen gas plasma. Strong modulation of the 391.4 nm superradiance with a period of 1.3 fs is observed when the delay between the two seeding pulses are finely tuned, pinpointing the essential role of macroscopic coherence in this lasing process. Based on this time-resolved method, the complex temporal evolution of the macroscopic coherence between two involved energy levels has been experimentally revealed, which is found to last for around 10 picoseconds in the low gas pressure range. These observations provide a new level of control on the "air lasing" based on nitrogen ions, which can find potential applications in optical remote sensing.

References in corpus (8)

• High gain backward lasing in air
• High-brightness switchable multi-wavelength remote laser in air
• Population Redistribution among Multiple Electronic States of Molecular Nitrogen Ions in Strong Laser Fields
• Recollision induced superradiance of ionized nitrogen molecules
• Self-seeded lasing in ionized air pumped by 800 nm femtosecond laser pulses
• Backward stimulated radiation from filaments in Nitrogen gas and air pumped by circularly polarized 800 nm femtosecond laser pulses
• Remote creation of strong and coherent emissions in air with two-color ultrafast laser pulses
• Signature of superradiance from a nitrogen gas plasma channel produced by strong field ionization

Cited by in corpus (6)

• Rotational Quantum Beat Lasing Without Inversion
• Role of rotational coherence in femtosecond-pulse-driven nitrogen ion lasing
• Structured air lasing of N2+
• Control of ${\text{N}}_2^{+}$ Air Lasing
• Controlling the polarization of nitrogen ion lasing
• Ramsey interferometry through coherent $X^2{\Sigma }_g^{+}-A^2{\Pi }_u-B^2{\Sigma }_u^{+}$ coupling and population transfer in N${}_2^{+}$ air laser