Snively Christopher M, Pellerin Christian, Rabolt John F, Chase D Bruce
Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA.
Anal Chem. 2004 Apr 1;76(7):1811-6. doi: 10.1021/ac0499118.
A novel method is presented that is capable of collecting time-resolved vibrational spectroscopic information with sub-100-micros temporal resolution. Unlike previous step scan FT-IR approaches, the phenomena under study do not necessarily need to be repeatable. The methodology described herein is based on the planar array infrared (PA-IR) technique, which utilizes a spectrograph for wavelength dispersion and a mid-infrared focal plane array (FPA) detector for simultaneous detection of multiple wavelengths. Unlike previous PA-IR approaches, a rolling mode FPA is employed. This unique data readout mode, where data are read out of the array two rows at a time, is exploited to generate increased temporal resolution. The capabilities of this technique are demonstrated using the example of the electric field-induced Freedericksz transition of a nematic liquid crystal. It is shown that the orientational dynamics of a single transition can be tracked over a spectral range of 154 cm(-)(1) with a temporal resolution of 99.17 micros while requiring a total experimental time of less than 1 s.
本文提出了一种新方法，该方法能够以低于100微秒的时间分辨率收集时间分辨振动光谱信息。与以往的步进扫描傅里叶变换红外（FT-IR）方法不同，所研究的现象不一定需要是可重复的。本文所述方法基于平面阵列红外（PA-IR）技术，该技术利用光谱仪进行波长色散，并使用中红外焦平面阵列（FPA）探测器同时检测多个波长。与以往的PA-IR方法不同，采用了滚动模式FPA。这种独特的数据读出模式，即每次从阵列中读出两行数据，被用来提高时间分辨率。以向列型液晶的电场诱导弗雷德里克兹转变为例，展示了该技术的能力。结果表明，单个转变的取向动力学可以在154 cm⁻¹的光谱范围内以99.17微秒的时间分辨率进行跟踪，而总实验时间不到1秒。
