Theoretical Analysis of Chirped Pulse Effects on Plasma Formation in Water Liquid Jet

Abstract

We present a theoretical study of how linear chirp controls plasma density in a water jet using a two-stage framework. Stage I solves carrier-population and current equations at a single point, driven by a chirped super-Gaussian pulse. By fixing bandwidth and normalizing for intensity, we isolate a chirp-only response of plasma density, which exceeds unity and shows a consistent advantage for negative over positive chirp. Stage II propagates the field in water via the angular-spectrum method and applies the same equations across space. Normal dispersion reverses the trend: the chirp-only plasma density decreases as chirp grows, negative chirp remains less detrimental, and suppression is strongest for longer FTL pulses (e.g., 80 fs) due to dispersion-induced temporal spreading and spatio-temporal desynchronization. This study separates spectral-phase effects from bandwidth and intensity, yields testable predictions for water jets, and provides a foundation for future experiments and self-consistent propagation models.