Nanometer-precision surface metrology of millimeter-size stepped objects using full-cascade-linked synthetic-wavelength digital holography using a line-by-line full-mode-extracted optical frequency comb
Abstract
Digital holography (DH) is a powerful tool for surface profilometry of objects with sub-wavelength precision. In this article, we demonstrate full-cascade-linked synthetic-wavelength DH (FCL-SW-DH) for nanometer-precision surface metrology of millimeter-size stepped objects. 300 modes of optical frequency comb (OFC) with different wavelengths are sequentially extracted at a step of mode spacing from a 10GHz-spacing, 3.72THz-spanning electro-optic modulator OFC (EOM-OFC). The resulting 299 synthetic wavelengths and a single optical wavelength are used to generate a fine-step wide-range cascade link covering within a wavelength range of 1.54 um to 29.7 mm. We determine the 0.1000mm-stepped surface with axial uncertainty of 6.1 nm within the maximum axial range of 14.85 mm.
Keywords
Cite
@article{arxiv.2301.10476,
title = {Nanometer-precision surface metrology of millimeter-size stepped objects using full-cascade-linked synthetic-wavelength digital holography using a line-by-line full-mode-extracted optical frequency comb},
author = {Eiji Hase and Yu Tokizane and Kazuki Sadahiro and Takeo Minamikawa and Isao Morohashi and Takeshi Yasui},
journal= {arXiv preprint arXiv:2301.10476},
year = {2023}
}
Comments
22 pages, 6 figures