Switched Wave Packets with Spectrally Truncated Chirped Pulses

TL;DR

This paper introduces a novel method for creating switched wave packets using spectrally truncated chirped laser pulses, demonstrated through experiments and simulations on molecular alignment, with implications for controlling molecular dynamics.

Contribution

The study presents a new spectrally truncated chirped pulse technique for generating switched wave packets, validated by experiments and numerical simulations on molecular alignment.

Findings

Alignment degree peaks at pulse maximum

Sharp drop in alignment after truncation with revivals

Excellent agreement between experiment and Schrödinger equation simulations

Abstract

A new technique for obtaining switched wave packets using spectrally truncated chirped laser pulses is demonstrated experimentally and numerically by one-dimensional alignment of both linear and asymmetric top molecules. Using a simple long-pass transmission filter, a pulse with a slow turn on and a rapid turn off is produced. The degree of alignment, characterized by $\langle\cos^2\theta_\text{2D}\rangle$ rises along with the pulse intensity and reaches a maximum at the peak of the pulse. After truncation $\langle\cos^2\theta_\text{2D}\rangle$ drops sharply but exhibits pronounced half and full revivals. The experimental alignment dynamics trace agrees very well with a numerically calculated trace based on solution of the time-dependent Schr\"odinger equation. However, the extended periods of field-free alignment of asymmetric tops following pulse truncation reported previously is not reproduced in our work.