共焦显微测量是一种很有前景的技术，具有非接触测量和高精度位移识别能力，广泛应用在芯片加工、高精密仪器制造、生物医学、材料化学、工业检测等领域。其沿轴向位置高精度扫描的二维图像可用于三维重建，然而，扫描的速度限制了图像的采集速率，为了克服这一局限性，研究人员提出了许多方法对传统的共聚焦显微镜系统进行了改进。例如，基于扫描振镜光束扫描型共焦显微镜、基于数字微镜装置的共焦显微镜、差分式扫描共焦显微镜等。本文主要讨论了各种共聚焦显微镜的工作原理、物镜类型、扫描方法、优缺点及应用。随着光学核心部件的升级和各种准确、高效算法的出现，未来共焦显微镜的扫描速度会更快、应用范围更广、分辨率更高。

We present a unified electromagnetic modeling of coherence scanning interferometry, confocal microscopy, and focus variation microscopy as the most common techniques for surface topography inspection with micro- and nanometer resolution. The model aims at analyzing the instrument response and predicting systematic deviations. Since the main focus lies on the modeling of the microscopes, the light–surface interaction is considered, based on the Kirchhoff approximation extended to vectorial imaging theory. However, it can be replaced by rigorous methods without changing the microscope model. We demonstrate that all of the measuring instruments mentioned above can be modeled using the same theory with some adaption to the respective instrument. For validation, simulated results are confirmed by comparison with measurement results.

Line-field Confocal Optical Coherence Tomography (LC-OCT) is an imaging modality based on a combination of time-domain optical coherence tomography and reflectance confocal microscopy. LC-OCT provides three-dimensional images of semi-transparent samples with a spatial resolution of ∼1 μm. The technique is primarily applied to in vivo skin imaging. The image contrast in LC-OCT arises from the backscattering of incident light by the sample microstructures, which is determined by the optical scattering properties of the sample, characterized by the scattering coefficient μ_s and the scattering anisotropy factor g. In biological tissues, the scattering properties are determined by the organization, structure and refractive indexes of the sample. The measurement of these properties using LC-OCT would therefore allow a quantitative characterization of tissues in vivo. We present a method for extracting the two scattering properties μ_s and g of tissue-mimicking phantoms from 3D LC-OCT images. The method provides the mean values of μ_s and g over a lateral field of view of 1.2 mm × 0.5 mm (x × y). It can be applied to monolayered and bilayered samples, where it allows extraction of μ_s and g of each layer. Our approach is based on a calibration using a phantom with known optical scattering properties and on the application of a theoretical model to the intensity depth profiles acquired by LC-OCT. It was experimentally tested against integrating spheres and collimated transmission measurements for a set of monolayered and bilayered scattering phantoms.

共聚焦显微镜具有较高的空间分辨率和信号背景比，能对生物样品进行三维层析成像，在医学与生物学领域有着广泛的应用。近红外二区（NIR-II，900~1 880 nm）波段的光在生物组织中具有适中的吸收、较低的散射，以及非常弱的生物组织自发荧光，因此，NIR-II荧光活体成像具有大深度、高对比度等优势。点激发、点探测的NIR-II共聚焦显微技术结合了上述二者的优势，在大深度生物成像中具有高空间分辨率和高信号背景比等优点，因此在生物医学领域得到了广泛应用。此综述将从NIR-II共聚焦显微技术的原理出发，阐述其发展进程、以及基于此项技术开展的生物医学成像应用，探讨NIR-II共聚焦显微技术未来的改进和发展方向。