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Diffuser speckle model: application to multiple moving diffusers.

W N Partlo, W G Oldham

|September 11, 2010

Summary

This study models light scattering through diffusers, revealing how diffuser roughness impacts light spread and speckle. Faster rotation of counter-rotating diffusers enhances speckle decorrelation for clearer imaging.

Area of Science:

Optics and Photonics
Materials Science

Background:

Speckle patterns arise from coherent light scattering through diffusers.
Understanding diffuser properties is crucial for controlling speckle noise in optical systems.

Purpose of the Study:

To develop a simple model for light scattering through diffusers.
To investigate the relationship between diffuser properties and speckle decorrelation.
To analyze the interaction of multiple diffusers in a despeckling system.

Main Methods:

Applied a Gaussian model for diffuser thickness variations.
Derived relations between scattering cone and decorrelation properties.
Utilized simulations and experimental measurements for verification.
Employed a nanosecond-pulsed laser source and moderate diffuser rotation speeds.

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Main Results:

The model equates diffusers to randomized lenslet arrays, linking roughness to scattering and decorrelation.
A decrease in decorrelation distance for counter-rotating diffusers correlates with an increased scattering cone.
Significant speckle decorrelation was achieved with moderate diffuser rotation.

Conclusions:

The developed model accurately predicts diffuser scattering and decorrelation behavior.
Controlled diffuser rotation is effective for speckle reduction in optical systems.
This research offers insights into optimizing diffusers for applications requiring speckle mitigation.