Development of a Scanning Near-field Infrared Microscope Based on a Free Electron Laser

为发展最先进的扫描近场红外显微镜提供了资金，该显微镜涉及使用高度准直、可调谐的红外源，如自由电子激光器。该仪器预计将在材料科学和生物系统中有许多应用，因为它结合了红外光谱的精细光谱分辨率和低至0.05微米的高分辨率成像，而不影响传统红外光谱的频率分辨率。此外，本质上大的特征吸收系数在红外意味着它是有可能获得图像的对比度大1分之一的105而不诉诸任何染色程序。所提出的显微镜应满足长期以来对一种成像技术的需要，这种技术能够无损地识别表面的化学成分。长期以来，人们一直认识到红外光谱与成像技术的结合将为无损检测表面提供一种有价值的技术。然而，当与传统成像技术一起使用时，这种技术的前景受到红外辐射长波所设定的较差空间分辨率的限制。在这项工作中，利用光学近场扫描探针显微镜的最新突破，以及自由电子激光器等高度准直、可调红外光源的可用性，构建了一个空间分辨率为0.05微米的红外近场显微光谱仪。这种新型仪器有可能彻底改变材料的表征。

Funds are provided for the development of a state-of-art scanning near-field infrared microscope that involves the use of highly collimated, tunable infrared sources such as free electron lasers. This instrument is expected to have many applications in both materials science and biological systems, because it combines the exquisite spectral resolution of infrared spectroscopy with high-resolution imaging down to 0.05 micrometers without compromising on the frequency resolution of conventional IR spectroscopy. Furthermore, the intrinsically large characteristic absorption coefficients in the infrared mean that it is possible to obtain images with contrast as large as 1 part in 105 without resorting to any staining procedures. The proposed microscope should satisfy a long-felt need for an imaging technique that is capable of non-destructive identification of the chemical composition of surfaces. %%% It has long been appreciated that the combination of infrared spectroscopy with imaging would provide a valuable technique for examining surfaces non-destructively. However, the promise of this technique was limited by the poor spatial resolution set by the long wavelengths of the infrared radiation when used with conventional imaging techniques. In this work, the recent breakthroughs in optical near-field scanning probe microscopy, and the availability of highly collimated, tunable infrared sources such as free electron lasers, are used to construct an infrared near-field microspectroscope that can achieve a spatial resolution of 0.05 micrometers. This novel instrument has the potential for revolutionizing the characterization of materials.