Extreme nonlinear Raman interaction of an ultrashort nitrogen ion laser with an impulsively excited molecular wavepacket

Abstract

We report generation of cascaded rotational Raman scattering up to 58th orders in coherently excited CO_2 molecules. The high-order Raman scattering, which produces a quasiperiodic frequency comb with more than 600 sidebands, is obtained using an intense femtosecond laser to impulsively excite rotational coherence and the femtosecond-laser-induced N_2^+ lasing to generate cascaded Raman signals. The novel configuration allows this experiment to be performed with a single femtosecond laser beam at free-space standoff locations. It is revealed that the efficient spectral extension of Raman signals is attributed to the specific spectra-temporal structures of N_2^+ lasing, the ideal spatial overlap of femtosecond laser and N2+ lasing, and the guiding effect of molecular alignment. The Raman spectrum extending above 2000 cm^-1 naturally corresponds to a femtosecond pulse train due to the periodic revivals of molecular rotational wavepackets.

arXiv comment17 pages, 4 figures

References in corpus (5)

• Optical frequency comb technology for ultra-broadband radio-frequency photonics
• Recollision induced superradiance of ionized nitrogen molecules
• 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
• Generation of Spectral Clusters in a Mixture of Noble and Raman-Active Gases

Cited by in corpus (2)

• Amplification of light pulses with orbital angular momentum (OAM) in nitrogen ions lasing
• Revisiting self-seeding mechanism by generating vector ultraviolet N${}_2^{+}$ lasing