School of Physics, Trinity College Dublin, Dublin 2, Republic of Ireland.
J Phys Condens Matter. 2010 Mar 5;22(8):084018. doi: 10.1088/0953-8984/22/8/084018.
Optical techniques for probing surface and interface structure are introduced and recent developments in the field are discussed. These techniques offer significant advantages over conventional surface probes: all pressure ranges of gas-condensed matter interfaces are accessible and liquid-liquid, liquid-solid and solid-solid interfaces can be probed, due to the large penetration depth of the optical radiation. Sensitivity and discrimination from the bulk are the two challenges facing optical techniques in probing surface and interface structure. Where instrumental improvements have resulted in enhanced sensitivity, conventional optical techniques can be used to characterize heterogeneous adsorbed layers on a substrate, often with sub-monolayer resolution. Nanoscale lateral resolution is possible using scanning near-field optics. A separate class of techniques, which includes reflection anisotropy spectroscopy, and nonlinear optical probes such as second-harmonic and sum-frequency generation, uses the difference in symmetry between the bulk and the surface or interface to suppress the bulk contribution. A perspective is presented of likely future developments in this rapidly expanding field.
介绍了用于探测表面和界面结构的光学技术，并讨论了该领域的最新发展。与传统的表面探针相比，这些技术具有显著的优势：由于光学辐射的穿透深度大，所有气相凝聚态物质界面的压力范围都可以被探测到，并且可以探测液-液、液-固和固-固界面。探测表面和界面结构时，光学技术面临的两个挑战是灵敏度和与体相的区分。在仪器改进提高了灵敏度的地方，传统的光学技术可用于对衬底上的非均相吸附层进行表征，通常具有亚单层分辨率。利用扫描近场光学技术可以实现纳米级的横向分辨率。另一类技术包括反射各向异性光谱学以及二次谐波和和频产生等非线性光学探针，它们利用体相与表面或界面之间的对称性差异来抑制体相的贡献。本文对这一快速发展领域未来可能的发展趋势进行了展望。
