Smart optical coherence tomography for ultra-deep imaging through highly scattering media

Area of Science:

• Biomedical Optics
• Wave Scattering
• Photonics

Background:

• Multiple scattering in disordered media hinders deep tissue imaging.
• Optical coherence tomography (OCT) is limited to ~1 mm depth in human tissues due to scattering and aberrations.
• Existing methods struggle to overcome significant scattering backgrounds.

Purpose of the Study:

• To develop a new optical imaging approach to overcome the depth limitations of current techniques.
• To extend the imaging depth beyond the capabilities of optical coherence tomography.
• To enable ultra-deep tissue imaging in scattering biological media.

Main Methods:

• A matrix approach combining ballistic wave discrimination and iterative time reversal.
• Theoretical modeling and experimental validation of the proposed technique.
• Demonstration of imaging through highly scattering media with extremely low ballistic photon fractions.

Main Results:

• Extended imaging depth by at least a factor of 2 compared to optical coherence tomography.
• Successfully imaged through a strongly scattering layer with a ballistic photon fraction of 1 in 10^12.
• Demonstrated the feasibility of the matrix approach for overcoming severe scattering.

Conclusions:

• The proposed matrix approach offers a significant advancement for deep tissue optical imaging.
• This method pushes the fundamental limits imposed by scattering and aberrations.
• Opens new possibilities for ultra-deep imaging applications in biological tissues.