Fig. 3.

Simulated electric field amplitude profile at 1000 nm wavelength, when an optical beam is launched from the top side. (a) A Gaussian beam is launched into a uniform medium with a refractive index of 1.35, showing a well-focused spot at the target depth. (b) A Gaussian beam is launched into a turbid medium, showing the effect of multiple scattering. (c) The optimal beam is launched into the same turbid medium, showing a well-focused spot at the target depth. (d–f) Magnified phase profiles of the white dashed region in (a–c), respectively.