Abstract
Two common-path interferometers based on ${{\rm CO}_2}$ and ${\rm Nd}{:}{{\rm Y}_3}{{\rm Al}_5}{{\rm O}_{12}}$ (Nd:YAG) lasers are benchmarked with a two-arm microwave interferometer on a hydrogen plasma produced by an RF discharge and injected into a large magnetic-confinement vessel. The ${\sim}{10^{19}}\;{{\rm m}^{- 2}}$ line-integrated electron density is clearly measured in agreement by the interferometers. The frequency spectrum of the measured data is analyzed on the 20 kHz range for all interferometers and up to 600 kHz for the Nd:YAG laser-based interferometer. Mechanical vibration measurements performed on the components of the two common-path interferometers result in a peak-to-peak displacement up to about one and twenty wavelengths for the ${{\rm CO}_2}$ and Nd:YAG laser-based interferometers, respectively. Such results set for the first time, to the best of our knowledge, a quantitative limit for the displacement that the two second-harmonic dispersion interferometers can sustain while still providing a high sensitivity for accurate plasma density measurements.
© 2020 Optical Society of America
Full Article | PDF ArticleMore Like This
Shishi Li, Meirong Dong, Lihua Cheng, Fasheng Luo, Weihao Zhao, and Jidong Lu
Appl. Opt. 59(25) 7638-7645 (2020)
Esrom Kifle, Pavel Loiko, Lauren Guillemot, Jean-Louis Doualan, Florent Starecki, Alain Braud, Thierry Georges, Julien Rouvillain, and Patrice Camy
Appl. Opt. 59(25) 7530-7539 (2020)
Daniel Matteo, Jeremy Pigeon, Sergei Tochitsky, Ilan Ben-Zvi, and Chan Joshi
Appl. Opt. 59(26) 7912-7917 (2020)