Unidirectional phase-Doppler method for particle-size measurements.

Area of Science:

• Optical Physics
• Particle Characterization
• Metrology

Background:

• Accurate particle sizing is crucial in various scientific and industrial applications.
• Existing methods for sizing moving particles can be limited in precision or applicability.
• Polarization-based optical techniques offer unique advantages for probing particle properties.

Purpose of the Study:

• To develop a novel, unidirectional phase-Doppler method for sizing moving spherical particles.
• To establish a linear relationship between phase difference and particle diameter.
• To optimize polarization conditions for enhanced measurement accuracy.

Main Methods:

• Utilizing a unidirectional phase-Doppler technique with two polarized Doppler beat signals.
• Analyzing the phase difference of scattered light at different polarization angles.
• Employing geometrical optics approximation and generalized Lorenz-Mie theory for numerical investigation.
• Conducting experimental validation with polystyrene and glass particles.

Main Results:

• Demonstrated a linear proportionality between the phase difference and particle diameter.
• Identified optimal polarization conditions for accurate particle sizing.
• Experimental results confirmed the effectiveness of the proposed method.

Conclusions:

• The proposed phase-Doppler method provides a novel and effective approach for sizing moving spherical particles.
• The technique is sensitive to particle diameter, refractive index, and optical system geometry.
• This method holds promise for applications requiring precise characterization of dynamic particle systems.