Feasibility of using glory and speckle patterns for sizing spherical and irregular particles

Area of Science:

• Optics and Photonics
• Particle Characterization
• Laser Light Scattering

Background:

• Accurate particle sizing is crucial in various scientific and industrial applications.
• Traditional methods may face limitations with irregular particle shapes or specific size ranges.
• Laser light scattering offers a non-intrusive approach for particle analysis.

Purpose of the Study:

• To investigate a novel backscattered laser light technique for sizing spherical and irregular particles.
• To develop and validate a theoretical model for particle size retrieval from interference patterns.
• To apply the technique to water droplets in both liquid and frozen states.

Main Methods:

• Illumination of single water droplets with a laser light source.
• Recording of glory and speckle interference patterns in the backscatter region using a CCD camera.
• Development of a theoretical model based on geometrical optics approximation for data analysis.

Main Results:

• Successful recording and analysis of glory and speckle interference patterns.
• Demonstrated ability to retrieve particle sizes for water droplets ranging from 1 to 2 mm.
• Satisfactory agreement between the theoretical model predictions and experimental data.

Conclusions:

• The developed backscattered laser light technique shows promise for accurate particle sizing.
• The theoretical model provides a reliable basis for analyzing interference patterns.
• Further development of this technique is encouraged for broader applications in particle characterization.