Mesoscopic Theory of Wavefront Shaping to Focus Waves Deep Inside Disordered Opaque Media

We describe the theory of focusing waves to a predefined focal point deep inside disordered 3D opaque media by shaping N external field sources, a technique known as wavefront shaping [1]. Our study is motivated by experiments where wavefront shaping, mediated by controlled interference of scattered waves, appears to surprisingly coexist with a classical-diffusion picture where interference appears absent in 3D, 2D, and 1D [2]–[4].