High-resolution adaptive optical imaging within thick scattering media using closed-loop accumulation of single...

Area of Science:

• Biomedical Optics
• Optical Imaging
• Microscopy

Background:

• Thick biological tissues cause light scattering and wave aberrations, limiting imaging depth and resolution in conventional optical microscopy.
• Existing methods struggle to address both multiple scattering and aberrations simultaneously, restricting sub-micron resolution to shallow depths.

Purpose of the Study:

• To develop an optical coherence imaging method capable of identifying and eliminating wave aberrations independently of multiple light scattering.
• To enhance deep-tissue imaging resolution and penetration depth in biological samples.

Main Methods:

• The proposed method utilizes time-gated complex-field maps of backscattered waves across multiple illumination channels.
• It employs a closed-loop optimization process for signal waves, incorporating both forward and phase-conjugation techniques.
• Aberrations of incident and reflected waves are identified and corrected separately.

Main Results:

• Demonstrated a Strehl ratio enhancement exceeding 500 times, significantly outperforming conventional adaptive optics.
• Achieved a spatial resolution of 600 nm.
• Enabled imaging at depths up to seven scattering mean free paths within biological tissues.

Conclusions:

• The developed optical coherence imaging method effectively overcomes the limitations of light scattering and aberrations in thick tissues.
• This advancement offers a substantial improvement in deep-tissue imaging resolution and penetration, paving the way for new biological investigations.