  Imaging through diffusers presents a challenging problem with various digital
image reconstruction solutions demonstrated to date using computers. We present
a computer-free, all-optical image reconstruction method to see through random
diffusers at the speed of light. Using deep learning, a set of diffractive
surfaces are designed/trained to all-optically reconstruct images of objects
that are covered by random phase diffusers. We experimentally demonstrated this
concept using coherent THz illumination and all-optically reconstructed objects
distorted by unknown, random diffusers, never used during training. Unlike
digital methods, all-optical diffractive reconstructions do not require power
except for the illumination light. This diffractive solution to see through
diffusers can be extended to other wavelengths, and might fuel various
applications in biomedical imaging, astronomy, atmospheric sciences,
oceanography, security, robotics, among others.
