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Updated: May 31, 2026

Construction and Characterization of External Cavity Diode Lasers for Atomic Physics
Published on: April 24, 2014
Two-dimensional electronic spectroscopy with double modulation lock-in detection: enhancement of sensitivity and
Ramūnas Augulis1, Donatas Zigmantas
1Department of Chemical Physics, Lund University, Lund, Sweden.
Abstract:
In many potential applications of two-dimensional (2D) electronic spectroscopy the excitation energies per pulse are strictly limited, while the samples are strongly scattering. We demonstrate a technique, based on double-modulation of incident laser beams with mechanical choppers, which can be implemented in almost any non-collinear four wave mixing scheme including 2D spectroscopy setup. The technique virtually eliminates artifacts or "ghost" signals in 2D spectra, which arise due to scattering and accumulation of long-lived species. To illustrate the advantages of the technique, we show a comparison of porphyrin J-aggregate 2D spectra obtained with different methods following by discussion.
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