Houle W A, Engel W, Willig F, Rempfer G F, Griffith O H
Ultramicroscopy. 1982;7(4):371-80. doi: 10.1016/0304-3991(82)90261-3.
The depth of information is defined as the distance below the surface of a specimen from which information is contributed at a specific resolution. A simplified model of photoemission is used to explore the relationship between electron escape depths and depth of information in photoelectron microscopy (PEM or photoemission electron microscopy). The depth of information is equal to the escape depth when the escape depth is small relative to the instrument resolution. When the escape depth is large compared to the instrument resolution or when information is carried for example by reflected light, the image consists of well resolved surface detail at the instrument resolution and dimmer, more diffuse, images of detail below the surface. Thus the same sample can exhibit different depths of information depending on the image details of interest. Other mechanisms of transmitting information to the surface, for example induced topography, are discussed, and experimental examples are given.
信息深度定义为标本表面以下能以特定分辨率提供信息的距离。使用光发射的简化模型来探究光电子显微镜（PEM或光发射电子显微镜）中电子逸出深度与信息深度之间的关系。当逸出深度相对于仪器分辨率较小时，信息深度等于逸出深度。当逸出深度比仪器分辨率大时，或者当例如由反射光携带信息时，图像由仪器分辨率下清晰分辨的表面细节以及表面以下较暗、更弥散的细节图像组成。因此，根据感兴趣的图像细节，同一标本可以呈现不同的信息深度。还讨论了将信息传输到表面的其他机制，例如诱导形貌，并给出了实验示例。
