Dead-zone free single-shot three-dimensional measurement using a high-repetition-rate Yb:fiber comb

• Published in: Optics continuum Vol. 1; no. 11; p. 2374
• Main Authors: Kurata, Shintaro, Ishii, Hirotaka, Terada, Kazuhiro, Morito, Tamaki, Tian, Haochen, Kato, Takashi, Minoshima, Kaoru
• Format: Journal Article
• Language: English
• Published: 15.11.2022
• ISSN: 2770-0208; 2770-0208
• DOI: 10.1364/OPTCON.474016

Using spectral interference from a highly chirped and high-repetition-rate optical frequency comb, a technique for dead-zone free one-shot three-dimensional (3D) imaging was developed. We generated continuously emitted pulse train (dead-zone-free pulse) using a highly chirped pulse from a 750-MHz repetition mode-locked Yb fiber comb. The measurement performances of the system were evaluated using an optical spectrum analyzer, and a longitudinal delay length resolution of 31 µm was obtained at arbitrary position for more than 400 mm range. Using an imaging spectrometer capable of multipoint spectroscopy, a delay length resolution of 81 µm was demonstrated. Finally, for a proof-of-concept measurement of 3D imaging, line profiles of three mirrors located in the middle of 200-mm-distance, corresponding to pulse-to-pulse interval, were measured without any scanning with an uncertainty of 0.7 mm. The uncertainty could be further improved by optical alignment and analysis to the level of 10 ∼ 100 µm at arbitrary position over the range not limited to pulse-to-pulse interval.