Holographic particle sizing and locating by using Hilbert-Huang transform

Area of Science:

• Optics and Photonics
• Data Analysis
• Particle Metrology

Background:

• Accurate particle sizing and localization are crucial in various scientific and industrial applications.
• Traditional methods often involve complex optical field reconstruction, which can be time-consuming and computationally intensive.

Purpose of the Study:

• To develop a novel, efficient method for direct particle sizing and axial locating from in-line digital holograms.
• To bypass the need for optical field reconstruction, thereby speeding up the analysis process.

Main Methods:

• Utilized the Hilbert-Huang transform (HHT) combined with empirical mode decomposition (EMD).
• Decomposed hologram intensity into intrinsic mode functions (IMFs).
• Analyzed the Hilbert spectrum of IMFs for particle axial location and size determination.

Main Results:

• Successfully determined particle axial location by fitting the Hilbert spectrum.
• Accurately derived particle size from spectral singularities.
• Demonstrated method validity and accuracy through numerical simulations and experimental validation.
• Achieved a fast and efficient process without requiring predefined basis functions.

Conclusions:

• The proposed HHT-based method offers a direct, rapid, and accurate approach for particle sizing and axial locating from digital holograms.
• This technique eliminates the need for optical field reconstruction, enhancing efficiency.
• The method shows potential for real-time applications in on-line particle sizing and 3D tracking.