Coherent Control of Vibrational State Population in a Nonpolar Molecule

TL;DR

This paper proposes a theoretical method for controlling vibrational state populations in nonpolar molecules using chirped laser pulses, enabling selective and complete population transfer through two-photon transitions.

Contribution

It introduces a novel coherent control scheme utilizing chirped pulses for vibrational state manipulation in nonpolar molecules, supported by numerical simulations.

Findings

Complete vibrational population transfer achievable with single or multiple chirped pulses.

Selective two-photon transition via coupling with dissociative states demonstrated.

Effects of focal averaging on control efficiency discussed.

Abstract

A coherent control scheme for the population distribution in the vibrational states of nonpolar molecules is proposed. Our theoretical analysis and results of numerical simulations for the interaction of the hydrogen molecular ion in its electronic ground state with an infrared laser pulse reveal a selective two-photon transition between the vibrational states via a coupling with the first excited dissociative state. We demonstrate that for a given temporal intensity profile the population transfer between vibrational states, or a superposition of vibrational states, can be made complete for a single chirped pulse or a train of chirped pulses, which accounts for the accumulated phase difference due to the AC Stark effect. Effects of a spatial intensity (or, focal) averaging are discussed.