Reflection-mode optical diffraction tomography at 1.3 µm for deep tissue imaging

Optical diffraction tomography (ODT) maps 3D refractive index (RI) distributions. RI maps provide valuable biophysical information, which aiding precise assessment of physiological states. Current ODT systems using visible light limit depth to few cell layers due to multi-scattering. We propose the use 1.3 µm illumination in ODT that avoids high water absorption and reduces the scattering, while maintaining ~ 1 µm resolution. We tested the imaging depth using homemade turbid solution that has similar attenuation length as brain tissues. We are now exploring the capabilities of the system for in vivo imaging applications.