微纳光子学中超快光谱的若干应用

Ultrafast time-resolved spectroscopy and its applications in micro-nano photonics

在光电器件的工作单元已经小到微米甚至纳米尺寸的今天,只有充分研究和了解单一元件及其复合系统的光物理性质,才能为进一步提高器件性能提出更好的可行性方案。将研究物质激发态过程的超快光谱技术引入微纳光子学,用来研究可能成为微纳光电器件中基本功能单元的纳米光电材料的光物理特性,探索微纳尺度下光与物质的相互作用基本规律,便能为更好地理解现有微纳光电器件的工作机理提供重要的研究手段,为以后新型微纳光电器件的制备和改进提供可靠的实验依据。文章简单介绍了超快光谱的工作原理,重点介绍了超快光谱技术在半导体纳米晶和荧光碳纳米材料的光物理性质研究中的应用及其在微纳光子学中的应用前景。最后,对同时具有高时间分辨与高空间分辨能力的四维时间分辨显微光谱进行了简要介绍。

Nowadays, the size of elements in optoelectronic devices has decreased to the micro-nano scale. For more feasible designs and improvement of device performance we need to have a deep understanding of the photophysics of the functional elements and composite systems. In this aspect, ultrafast spectroscopy is a powerful tool for unraveling the excited-state processes in condensed matter. Thus, the combinination of ultrafast spectroscopy with micro-nano photonics not only enables us to understand the fundamental photophysical properties of micro-nano opto-electronic elements and the basic principles of light-matter interactions at the micro-nanoscale, but also helps us to understand the mechanisms of current micro-nano optoelectronic devices. The experimental results from these interdisciplinary studies will also be helpful for the fabrication and improvement of the next generation of devices. Here we first introduce the fundamental principles of ultrafast spectroscopy, then review the recent progress in ultrafast spectroscopic studies on the photophysics of semiconductor nanocrystals and fluorescent carbon nanomaterials. Finally, a brief introduction to four-dimensional electron microscopy is presented.