The measurement of the optical Transmission Matrix (TM) enables to access
"open channels": input patterns, specific to each scattering structure, capable
to deliver very high transmission. Various approaches, based either on multiple
interferometric measurements or on systematic random testing of incident
wavefronts, enable to estimate the inputs required to excite these open
channels. Here, we provide for the first time an approach enabling the complete
and reference-less retrieval of the open channels. It is based on the full
mapping all the pairwise interference terms resulting from all the input modes
couples. We show that these interference terms are organized into a bi-dyadic
coupling matrix whose eigenvalues enables to access the open channel. A
disordered optical system, is thus behaving exactly like an Hopfield neural
network, where a specific input vector (an eigenvalue of the neurons' coupling
matrix) enables to retrieve a specific memory pattern. The proposed Hopfield
like open-channel-retrieval approach, enables to reach almost 100% of the
theoretically expected value of the Intensity. Moreover employing a digital
micromirror device to modulate light, we demonstrate high speed laser scanning
at the back of a disordered medium.Comment: 6 pages, 5 figure