Characterization of surface topography by confocal microscopy: II. The micro and macro surface irregularities

Abstract

In part I, considering the autofocus and intensity methods of measurement, the principles and performance of a confocal microscope were discussed. In this part, the details of the experiments, conducted to measure and assess micro and macro surface irregularities of various machined planar and cylindrical surfaces, using a confocal scanning optical microscope (CSOM) are described. The three-dimensional surface topographies of various machined planar surfaces and also the form errors, like roundness and cylindricity, are measured and analysed. The significance of the set of new parameters, proposed for characterizing three-dimensional surface roughness and roundness measurements, is indicated. The effect of filtering on the variation in values of three-dimensional surface-topography parameters is studied. The performance of the CSOM is compared with those of conventional stylus and interferometric methods. The system is shown to have a great number of advantages in terms of three-dimensional surface mapping of planar and cylindrical surfaces and recognition of details and analysis for characterization of surfaces.

A lateral super-resolution differential confocal technology with phase-only pupil filter

“…When a pinhole has an offset of u M in the axial direction, the axial intensity response function [3] is…”

“…Confocal microscopes (CMs) are now widely used as important tools for measurement of surface contours because of their good 3D chromatographic imaging capabilities [1][2][3][4]. The basic principle of the differential confocal microscopy (DCM) is to use the slopes of the CM's axial response curves to measure surface contours, and have been used to achieve an axial resolution of 2 nm [1].…”

“…A confocal scanning optical microscope based on DCM principle has been proposed for surface topography measurement and analysis [2]. In order to further improve the measurement accuracy and resolution of DCM, a new heterodyne confocal sensor based on DCM has been developed for the measurement of discontinuous surface profile, and it uses two heterodyne detectors in the receiving optical path to improve the common-mode rejection ratio, linearity and axial resolution of DCM [3]. Based on Ref.…”

“…Based on Ref. [3], a triheterodyne CM was built up to improve the DCM axial resolution and signal-to-noise ratio by dividing the CM measurement light path into three paths, and using three sets of focusing lenses, detectors and pinholes placed behind, on and before the focal plane to form three detection systems, and then, improving the DCM axial resolution and anti-environmental interference capability through pairwise heterodyne subtraction of three intensity signals with given phases received by the three detection systems and data processing [5].…”

Study on the Dot Gain and Tone Reproduction of Tissue Paper

“…The formation of ink film with the desired optical density on paper substrates is consequentially dependent on the ink receptivity by paper, which is determined by structure and optical properties of paper surface [6]. The development of print gloss is related to the rate at which the ink film hardens or sets, which in turn may be related to the pore structure of the paper surface [7][8][9]. Tissue paper can not perform the role of substrate smoothly.…”