Fourier transform infrared imaging: Theory and practice
Fourier transform infrared imaging: Theory and practice
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DOI：
10.1021/ac010380m
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发表时间：
2001-11-01
影响因子：
7.4
通讯作者：
Levin, IW
中科院分区：
文献类型：
--
作者：
Bhargava, R;Levin, IW
分析了采用阶跃扫描干涉仪和焦平面阵列探测器的微成像傅里叶变换红外光谱仪组件获得的光谱数据的信噪比。基于数据采集方法，给出了性能特性的理论描述，从理论上解释了捕获参数对信噪比的定量影响，并与实验进行了比较。为了获得在给定时间间隔内达到最高信噪比或在最短时间内达到给定信噪比的最佳策略，引入了特征图的概念。将理论分析推广到使用连续扫描干涉仪的红外显微成像中，列举了快速图像采集的优点，同时讨论了镜面定位误差引起的信噪比限制。为了更快地收集数据，提出了一种步进式扫描方法，其中保留了最佳探测器响应和信噪比优势。根据本文提出的表达式从理论上获得的信噪比可以很好地预测实验确定的值，并且可以用来了解改进性能所需的发展。最后，比较了显微成像系统和常规显微光谱仪器的信噪比。
The signal-to-noise ratio (SNR) of spectral data obtained from a microimaging Fourier transform infrared (FT-IR) spectrometer assembly, employing a step-scan interferometer and focal plane array detector, is analyzed. Based on the methodology of data collection, a theoretical description for the performance characteristics is proposed and quantitative effects of the acquisition parameters on the SNR are explained theoretically and compared to experiment. To obtain the best strategy for achieving either the highest SNR in a given time interval or for attaining a given SNR in the shortest time period, the concept of characteristic plots is introduced. The theoretical analysis is extended to Fr-IR microimaging employing continuous scan interferometers in which the advantages of fast image collection are enumerated, while SNR limitations arising from mirror positioning errors are discussed. A step-scan method is suggested for faster data collection in which an optimal detector response and SNR benefits are retained. Theoretically obtained SNRs based upon the expressions proposed in this paper predict experimentally determined values quite well and can be used to obtain an understanding of the required developments for improved performance. Finally, SNRs for both microimaging systems and conventional microspectroscopic instrumentation are compared.