Wang Xinhao, Wu Yingchun, Xu Dongyan, Wen Botong, Lv Qimeng, Wu Xuecheng
Opt Lett. 2022 Oct 15;47(20):5272-5275. doi: 10.1364/OL.471103.
This work proposed a synthetic aperture rainbow refractometry (SARR) by synthesizing rainbow signals of the same droplet with dual-wavelength laser beams, in order to increase the aperture of rainbow refractometry. In this way, the SARR can apply to long distance and small droplets measurement. An achromatic imaging system, which simultaneously records while separating the two rainbow signals in two channels of a color image, is elaborately designed. A data processing algorithm is developed to retrieve the optimal droplet refractive index and size. Numerical simulations of different droplet sizes from 10 m to 200 m certify the viability of the SARR. Proof-of-concept experiments of micron-sized ethanol droplets are performed with 1650 mm measurement distance. Results show that the SARR can accurately measure droplet refractive index and size with uncertainties of 2.3 × 10 and 2m, respectively. The feasibility and accuracy of the proposed SARR are successfully demonstrated, paving the way for rainbow refractometry applied to large-scale industrial applications.
这项工作通过用双波长激光束合成同一液滴的彩虹信号，提出了一种合成孔径彩虹折射仪（SARR），以增加彩虹折射仪的孔径。通过这种方式，SARR可应用于远距离和小液滴测量。精心设计了一种消色差成像系统，该系统在彩色图像的两个通道中分离两个彩虹信号的同时进行记录。开发了一种数据处理算法来检索最佳液滴折射率和尺寸。对10μm至200μm不同液滴尺寸的数值模拟证明了SARR的可行性。在1650mm测量距离下对微米级乙醇液滴进行了概念验证实验。结果表明，SARR能够分别以2.3×10⁻³和2μm的不确定度准确测量液滴折射率和尺寸。所提出的SARR的可行性和准确性得到了成功证明，为彩虹折射仪应用于大规模工业应用铺平了道路。
