Multiregion Light Control in Diffusive Media via Wavefront Shaping.

Wavefront shaping allows focusing light through or inside strongly scattering media, but the background intensity also increases which reduces the target's contrast. By combining transmission or deposition matrices for different regions, we construct joint operators to achieve spatially resolved control of light in diffusive systems. The eigenmode of a contrast operator can maximize the power contrast between a target and its surrounding. A difference operator enhances the power delivery to a target while avoiding the background increase. This work opens the door to coherent control of nonlocal effects in wave transport for practical applications.