A double-program short-coherence instantaneous phase-shifting interferometer and measurement method for spherical surface feature detection

Abstract

The invention discloses an octave type short coherence transient phase-shifting interferometer and a measurement method used for detecting spherical topographic characteristics and relates to the technical field of optical detection. The problems that a traditional time domain phase-shifting interference measurement device is narrow in detection range and low in measurement precision and is influenced by environmental factors are solved. The interferometer comprises a short coherence laser, a spatial filter, a beam splitter prism, an optical fiber coupling mirror, a polarization splitting prism, a lambda / 4 wave plate, a 4f beam-expanding system, a micro objective, a plane mirror, a single mode optical fiber, an optical fiber collimating lens, a corner cube mirror, a cube-corner prism, a lambda / 2 wave plate, a polarization splitting prism, a first parallel beam splitter, a second parallel beam splitter, a wave plate group, a polarizing film, an area array charge coupled device (CCD) and a computer. A positioning relationship among four interference images is obtained through four interference patterns of the area array CCD through the computer, so that the initial phase difference which corresponds to each pixel point in an interference field is solved, the optical path difference is further solved, and the spherical morphology is measured. The interferometer is suitable for detection of spherical topographic characteristics.

Description

technical field [0001] The invention relates to the technical field of optical detection, in particular to the technical field of optical detection of the three-dimensional shape of space objects. Background technique [0002] As one of the most commonly used component shapes, microspheres are used in many fields such as aerospace, military, industry, and medical treatment. The accuracy of their surface shape has a crucial impact on their performance. Although traditional detection methods, such as atomic force microscopes and confocal microscopes, have high longitudinal measurement accuracy, when the single measurement range is very small and high-precision mechanical scanning motion devices are required to achieve overall three-dimensional shape measurement, they are affected by mechanical motion. The impact of errors is serious, and at the same time, due to the single-point scanning measurement, there are problems such as low detection efficiency, poor lateral resolution,...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problems of the traditional time-domain phase-shifting interferometry device, the detection range of a single measurement is too small, the measurement accuracy is low, and it is easily affected by environmental factors, it provides a double-order short-coherent instantaneous Phase shifting interferometer and measuring method

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