Switched Wave Packets with Spectrally Truncated Chirped Pulses

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 $⟨{\cos }^2{\theta }_{\text{2D}}⟩$ rises along with the pulse intensity and reaches a maximum at the peak of the pulse. After truncation $⟨{\cos }^2{\theta }_{\text{2D}}⟩$ 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 Schrödinger equation. However, the extended periods of field-free alignment of asymmetric tops following pulse truncation reported previously is not reproduced in our work.

7 pages, 4 figures