Scattering from a moving spherical particle by two crossed coherent plane waves

Area of Science:

• Physics
• Optics
• Fluid Dynamics

Background:

• Mie scattering theory describes light interaction with particles.
• Laser Doppler velocimetry (LDV) uses scattered light to measure velocity.
• Understanding scattered signals is vital for accurate LDV measurements.

Purpose of the Study:

• To analyze Mie scattering properties of a moving spherical particle illuminated by two intersecting laser beams.
• To provide solutions for calculating time-varying scattered signals for LDV applications.
• To investigate the influence of key physical parameters on the scattered signal.

Main Methods:

• Exact analytical solution of Maxwell's equations for Mie scattering.
• Calculation of integrated scattered signal across a detector aperture.
• Modeling particle motion at constant velocity and plane wave illumination.

Main Results:

• The derived solutions are suitable for calculating time-varying scattered signals.
• Scattered signal strength shows strong dependence on particle size and refractive index.
• Cross beam angle and collection solid angle significantly impact the scattered signal.

Conclusions:

• The study provides a theoretical framework for analyzing scattered signals in cross-beam LDV.
• Accurate LDV measurements require careful consideration of particle characteristics and optical setup.
• The findings are essential for optimizing LDV systems in various scientific and engineering fields.