Multi-modal transport of intensity diffraction tomography microscopy with an electrically tunable lens [Invited]

Area of Science:

• Biophysics
• Optical Imaging
• Cell Biology

Background:

• Optical diffraction tomography (ODT) is vital for 3D imaging of biological samples without dyes.
• Challenges in ODT include limited refractive index specificity and coupled absorption-phase information.
• Existing methods struggle with complex biological specimens.

Purpose of the Study:

• To develop a high-speed 3D microscopy technique for decoupling phase and absorption information.
• To enhance the specificity and accuracy of refractive index and absorption imaging.
• To enable multi-modal imaging of diverse biological samples.

Main Methods:

• Introduced multi-modal transport of intensity diffraction tomography (MM-TIDT).
• Integrated an electrically tunable lens and modified illumination patterns (circular and annular apertures).
• Employed an alternating direction method of multipliers (ADMM) with total variation (TV) and non-negativity regularization.

Main Results:

• Successfully decoupled phase and absorption information for accurate 3D reconstruction.
• Achieved high-accuracy and robust reconstruction of complex refractive index and fluorescence distributions.
• Demonstrated capability to resolve fine structural details in microspheres, Spirulina, and labeled cells.

Conclusions:

• MM-TIDT offers a versatile platform for high-speed, multi-modal 3D imaging of biological specimens.
• The technique overcomes limitations of traditional ODT for complex samples.
• Enables advanced exploration of dynamic biological processes and cellular interactions.