Published in:
Review of Scientific Instruments, 92 (2021) 12
Language:
English
DOI:
10.1063/5.0063419
ISSN:
0034-6748;
1089-7623
Origination:
Footnote:
Description:
This paper introduces an optical measurement technique to enhance knife-edge interferometry (KEI) for edge topography characterization with a high resolution by shaping a beam of light incident on the sharp edge. The enhanced KEI forms spherical wavelets as a new light source by focusing a beam before the sharp edge by using an objective lens, and those wavelets interfere with the secondary wavelets diffracted at the sharp edge along the propagation direction. Unlike a conventional KEI that is limited to low spatial resolution due to a relatively large beam diameter, the enhanced KEI can increase the fringe spatial frequency and produce more data necessary for fringe analysis toward edge topography characterization. Edge samples with various edge conditions were used for validation. As a result, the enhanced KEI improved the resolution of edge topography characterization compared to the conventional KEI. This study has the potential to be utilized in high-resolution optical microscopy for edge topography characterization.