Augulis Ramūnas, Zigmantas Donatas
Department of Chemical Physics, Lund University, Lund, Sweden.
Opt Express. 2011 Jul 4;19(14):13126-33. doi: 10.1364/OE.19.013126.
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.
在二维（2D）电子光谱的许多潜在应用中，每个脉冲的激发能量受到严格限制，而样品具有很强的散射性。我们展示了一种基于用机械斩波器对入射激光束进行双调制的技术，该技术几乎可以在任何非共线四波混频方案中实现，包括二维光谱设置。该技术实际上消除了二维光谱中由于长寿命物种的散射和积累而产生的伪像或“鬼”信号。为了说明该技术的优点，我们展示了用不同方法获得的卟啉J聚集体二维光谱的比较，并进行了讨论。
