Raman spectroscopy on deformed droplets: theory and experiment

Accurate absolute measurements of the Raman backscattering differential cross-section of water and ice and its dependence on the temperature and excitation wavelength

“…For bulk liquid water, the agreement between theory and experiments is rather semi quantitative [12,13,14]. The situation is even more complex for small water droplets and ice crystals because their morphology (shape) affects the scattering [15,16,17,18] unless their sizes are an order of magnitude smaller than the wavelength of light or so large that the surface effects can be either ignored or accounted for (reflection from a large flat surface is an example where the calculations are simple). Generally, the morphology especially of the ice crystals can be very diverse.…”

Influence of Varying Thermodynamic Magnitudes on the Acoustic Levitation of Particles in a Single Axis Ultrasonic Levitator

“…The backscattered Raman signal was used by [16] for the chemical analysis of levitated drops. [17] showed theoretically and experimentally the possibility of Raman scattering on deformed acoustically levitated droplets by a scattering angle of 90°. A method of calculation of the acoustic radiation pressure based on the boundary element method was presented by [18] and the influence of the acoustic field on the external flow is described in [19].…”

“…The particle oscillation in the radial direction can lead to a dispersion of the Raman scattering intensity. [16], [17] obtained different intensity profiles for scanning in the radial and axial directions, which were attributed to the particle oscillations in the radial direction.…”

Development of a single-axis ultrasonic levitator and the study of the radial particle oscillations

“…The effects of low radial stability have been observed by some authors. Esen et al [2] noted that the particle oscillation in the radial direction can lead to a dispersion of the Raman scattering intensity and Tuckermann et al [3] obtained different intensity profiles for scanning in the radial and axial directions, which were attributed to the particle oscillations in the radial direction. Aiming to reduce the lateral oscillations of the levitated particle, this paper presents the development of a new single-axial acoustic levitator, which is formed by a piezoelectric ultrasonic transducer with a concave radiating surface and a concave reflector.…”