3D imaging in volumetric scattering media using phase-space measurements

Area of Science:

• Optical imaging and metrology
• Computational imaging and inverse problems
• Photonics and wave phenomena

Background:

• Scattering materials significantly impede the direct imaging and localization of embedded objects.
• Traditional imaging methods struggle to resolve sources within turbid media due to light diffusion.
• Phase-space imaging offers a novel approach to capture angular information lost in scattering.

Purpose of the Study:

• To demonstrate 3D localization of multiple point sources within scattering media using phase-space imaging.
• To develop a robust reconstruction algorithm for overcoming the challenges posed by volumetric scattering.
• To validate the technique experimentally for practical applications.

Main Methods:

• Derivation of a multi-slice forward model for homogenous volumetric scattering.
• Development of a sparsity-exploiting reconstruction algorithm to constrain the inverse problem.
• Acquisition of high-resolution 4D phase-space data using a spectrogram setup.

Main Results:

• Phase-space imaging effectively measures the angular spreading caused by scattering.
• The 4D measurements for 3D reconstruction provide robustness against multiple scattering effects.
• Successful experimental recovery of the 3D positions of multiple LEDs embedded in turbid media.

Conclusions:

• Phase-space imaging is a powerful tool for 3D source localization in scattering environments.
• The developed reconstruction method enhances accuracy and robustness in challenging optical conditions.
• This technique holds promise for applications requiring non-invasive imaging within scattering materials.