• Current Optics and Photonics
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• v.7 no.4
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• pp.325-336
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• 2023

We review recent research related to shearing interferometry, reported over the last two decades. Shearing interferometry is categorized as azimuthal, radial, or lateral shearing interferometers by its fundamental principle to generate interference. In this review the research trends for each technique are provided, with a summary of experimental results containing theoretical background, the optical configuration, analysis, and perspective on its application fields.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.25-26
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• 2006

The method measuring the absolute position of a point diffraction source emitting a spherical wavefront in three-dimension is proposed. Two-dimensional interference of spherical wavefronts is used to overcome ambiguity of phase order. The spherical wavefront is explicated by Taylor series expansion, from which a radius of curvature of a spherical wavefront and its center position in three-dimension are obtainable. The spherical wavefront is reconstructed by a modified lateral shearing interferometer, which uses single-mode fiber as a point diffraction source.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.161-166
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• 1997

A improved method to measure the wavefront aberration of aspheric lens is described. In this study, which is a kind of lateral shearing interferometry, a sinusoidal diffraction grating is used for better quality of interferogram. Also,the grating is inclined to horizontal axis for obtaining the two orthogonal derivatives and minimizing moving error simultaneously. Measurement result shows that the repeatability is about 6 times better then that of previouse Ronchi Test.

• Korean Journal of Optics and Photonics
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• v.34 no.6
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• pp.261-268
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• 2023

We propose a compact differential interference contrast microscopic module, which enables snapshot measurements for quantitative phase imaging. The proposed module adopts the lateral shearing interferometric principle, which can obtain self-interference without a reference. Due to the absence of the reference, the system is more stable than the typical interferometric systems. It uses a polarization grating to generate two laterally shifted wavefronts based on its birefringence and polarizing beam-splitting characteristics. Furthermore, the use of a polarization camera does not require sequential measurements for the phase extraction. In the experiments, we observe and measure the timely varying changes of various specimens to verify the system performance with the bright field images and phase contrast images. Because the proposed microscopic module also has the merit of being adaptable to typical microscopy instead of using an imaging camera, it can conveniently replace conventional contrast microscopy.