Center for Relativistic Laser Science

2017 ABC

Thick biological tissues give rise to not only the multiple scattering of incoming light waves, but also the aberrations of remaining signal waves. Due to the inability of existing optical microscopy to overcome both problems simultaneously, imaging depth warranting the sub-micron spatial resolution has remained extremely shallow. Here we present optical coherence imaging method that can identify aberrations of waves incident to and reflected from the samples separately, and eliminate such aberrations even in the presence of strong multiple light scattering. The proposed method records the time-gated complex-field maps of backscattered waves over various illumination channels, and performs closed-loop optimization of signal waves for both forward and phase-conjugation processes. We demonstrated the enhancement of Strehl ratio by more than 1,000 times, two orders of magnitude improvement over conventional adaptive optics, and achieved the spatial resolution of 600 nm up to the unprecedented imaging depth of 7 scattering mean free paths.