Warsaw University of Technology, Institute of Micromechanics and Photonics, 8 Sw A Boboli St, Warsaw 02-525, Poland.
Opt Lett. 2013 Jun 1;38(11):1878-80. doi: 10.1364/OL.38.001878.
In this Letter, a novel concept based on superresolution technique that enables the measurement of high gradient and deep topography objects using digital holographic (DH) microscopy is introduced. The major problem of DH systems is limited NA that prohibits the metrological characterization of object features of high frequencies. The proposed technique has the ability to extend spatial frequency spectrum of the measured topography by applying multidirectional plane wave illumination, which is experimentally realized with a grating. The technique recovers sample topography from the set of object waves with different object spectra that are converted into a set of topographies by using an algorithm which takes into account refraction. Application of this novel approach is experimentally validated by characterization of high gradient topography objects with maximum angle of tangent 65°.
在这封信件中，提出了一种基于超分辨率技术的新概念，该技术可利用数字全息（DH）显微镜测量高梯度和深形貌物体。DH 系统的主要问题是有限的数值孔径（NA），这限制了对高频对象特征的计量特性的描述。所提出的技术具有通过应用多方向平面波照明来扩展测量形貌的空间频谱的能力，这通过光栅在实验中得以实现。该技术通过使用考虑折射的算法，从一组具有不同对象谱的物波中恢复样本形貌，该算法将对象谱转换为一组形貌。通过对最大正切角为 65°的高梯度形貌物体的特征化，实验验证了这种新颖方法的应用。
