Bollen Viktor, Marston Philip L
Physics and Astronomy Department, Washington State University, Pullman, Washington 99164-2814,
J Acoust Soc Am. 2020 Aug;148(2):EL135. doi: 10.1121/10.0001697.
While acoustic vortex beams have many potential applications, the full implication of the phase information available in scattering experiments has not been developed. The present paper concerns observables in measured near-backward scattering from a sphere in water raster scanned through a first-order acoustic vortex beam. Symmetrically placed transducer elements were operated in a transmit-receive mode. Helicity-dependent projections of the spatial evolution of the scattering were used to display magnitude and phase information. The resulting phase swirl patterns were projection dependent and especially sensitive to the transverse position of the sphere. The magnitude also depended on the sphere's position relative to the beam's axial null.
虽然声涡旋光束有许多潜在应用，但散射实验中可用相位信息的全部意义尚未得到充分发掘。本文关注的是在水介质中，通过一阶声涡旋光束进行光栅扫描时，对球体近后向散射测量中的可观测现象。对称放置的换能器元件以收发模式工作。利用与螺旋度相关的散射空间演化投影来显示幅度和相位信息。所得的相位涡旋图案与投影有关，并且对球体的横向位置特别敏感。幅度也取决于球体相对于光束轴向零值的位置。
