Controlling rotational air lasing lineshape by carrier-envelope offset phase.

ABSTRACT: The carrier-envelope offset phase (CEP) of a few-cycle optical pulse is commonly used to control electron dynamics on the attosecond timescale, whereas lasing spectra from transitions between rotational states are generally emitted over much longer durations, typically nanoseconds. Here, we demonstrate CEP control of the rotational lasing spectra corresponding to the transition from B2Σu+(0) to X2Σg+(1) in N2+ cations, transforming its lineshape from a symmetric Lorentzian profile to an asymmetric Fano type-and vice versa. This lineshape modulation arises from the interference between the B-X coherence initiated by the main pulse and the supercontinuum (self seed) by self-phase modulation, resembling an "f-to-3f" interferometry. Additionally, for lasing lines with lower rotational quantum

SUBMITTER: Gao J 

PROVIDER: S-EPMC12579218 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature