Broadband-Enhanced Transmission through Symmetric Diffusive Slabs.

We report on a significant and broadband enhancement of the transmission through an opaque barrier, when placed between symmetric diffusive disordered slabs. The transmission enhancement is accompanied by a bimodal distribution of the transmission eigenvalues, and, for a given transmittance of the barrier, it finds an optimal value for a particular length of the disordered slabs. A simple model allows us to quantify the scalings between the parameters that show that the stronger the barrier, the stronger the maximum possible enhancement. The sensitivity to symmetry defects is also explored, displaying potential interest for wave based sensing.