Abstract

We extend rainbow refractometry to quantify the oscillations of a droplet in its fundamental mode. The oscillation parameters (frequency and amplitude damping), extracted using the time-resolved rainbow angular shift, are utilized to measure surface tension and viscosity of the liquid. Proof-of-concept experiments on an oscillating droplet stream produced by a monodisperse droplet generator are conducted. Results show that the relative measurement errors of surface tension and viscosity are 1.5% and 8.4% for water and 5.3% and 2.5% for ethanol. This approach provides an alternative mean for characterizing liquid surface properties, e.g., dynamic surface tension and viscosity, especially for liquids with a low Ohnesorge number.

© 2020 Optical Society of America

Surface temperature measurement of cooling and heating droplets by rainbow refractometry

Qimeng Lv, Yingchun Wu, and Xuecheng Wu
Appl. Opt. 61(25) 7455-7462 (2022)

Phase rainbow refractometry for accurate droplet variation characterization

Yingchun Wu, Jantarat Promvongsa, Sawitree Saengkaew, Xuecheng Wu, Jia Chen, and Gérard Gréhan
Opt. Lett. 41(20) 4672-4675 (2016)

Planar rainbow refractometry

Can Li, Qimeng Lv, Ning Li, Yingchun Wu, Xuecheng Wu, Chunsheng Weng, and Cameron Tropea
Opt. Lett. 46(23) 5898-5901 (2021)

Synthetic aperture rainbow refractometry

Xinhao Wang, Yingchun Wu, Dongyan Xu, Botong Wen, Qimeng Lv, and Xuecheng Wu
Opt. Lett. 47(20) 5272-5275 (2022)

Composition measurements of binary mixture droplets by rainbow refractometry

J. Wilms and B. Weigand
Appl. Opt. 46(11) 2109-2118 (2007)