Multi-Channel Selective Femtosecond Coherent Control Based on Symmetry Properties

TL;DR

This paper introduces a novel femtosecond coherent control scheme leveraging symmetry properties to independently tune multi-channel excitation yields, enabling precise manipulation of atomic absorption processes.

Contribution

It presents a new pulse shaping method that exploits symmetry invariance to achieve independent control of two-photon and three-photon absorption channels.

Findings

Independent tuning of multi-channel absorption yields achieved.

Two-photon dark pulses can induce tunable three-photon absorption.

Control range spans over an order of magnitude.

Abstract

We present and implement a new scheme for extended multi-channel selective femtosecond coherent control based on symmetry properties of the excitation channels. Here, an atomic non-resonant two-photon absorption channel is coherently incorporated in a resonance-mediated (2+1) three-photon absorption channel. By proper pulse shaping, utilizing the invariance of the two-photon absorption to specific phase transformations of the pulse, the three-photon absorption is tuned independently over order-of-magnitude yield range for any possible two-photon absorption yield. Noticeable is a set of two-photon dark pulses inducing widely-tunable three-photon absorption.