Article ID Journal Published Year Pages File Type
1542740 Optics Communications 2006 10 Pages PDF
Abstract

Based on weak phase approximation and the partial coherence theory, we analyze the image characteristics of a phase object using a microscope. We show that the image of the phase object is formed by the interplay between the phase distribution and the defocus.Using this theory, we also show the image characteristics of a differential interference contrast (DIC) microscope.We develop a method for extracting the phase component from the DIC image using two images with different retardation to reconstruct the phase distribution of the object. We call our new microscope a “retardation-modulated DIC (RM-DIC) microscope”. We describe the RM-DIC microscope and confirm our method using grating samples with depths of 20 and 50 nm.To measure the three-dimensional (3D) figures of the microstructures on the object using a DIC microscope we need to extract the phase component from the DIC image and to deconvolute the phase component by means of the modulation transfer function (MTF) of the DIC microscope.We conclude that our RM-DIC microscope can take quantitative measurements of the phase distribution, making it a very useful tool for 3D measurement of an object’s microstructures.

Related Topics
Physical Sciences and Engineering Materials Science Electronic, Optical and Magnetic Materials
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