Figure 5.

Principle of the optical transmission matrix. (a) The beam incident on a scattering sample is modulated by a spatial light modulator (SLM). In case of monochromatic radiation, a speckle pattern is observed behind the sample. (b) The field reflected from the SLM is considered to be composed of a number of independent sources indexed $n$. Since propagation in the sample is linear, the field observed at the $m$-th detector pixel can be described based on the incident field $E_n^{src}$ and the static and complex-valued transmission matrix $t_{mn}$; see Equation (2) [48]. Image from [8], with permission.