Wavefront-shaping-based pattern regeneration through the scattering medium.

Generating a specific pattern through a scattering medium is of utmost interest, but remains mostly restricted to weakly scattering or transparent samples. We present a wavefront-shaping-based approach to achieve a user-specified pattern through a strong scattering medium. We show that the virtual transmission matrices can be computed by convolving the transmission matrices with a virtual input wavefront. Interestingly, rather than a focused point, a pattern, which is the square of the modulus of the virtual input wavefront, can be regenerated after the scattering medium at different locations. As a proof of concept, we set up the experiments using a phase-only spatial light modulator and calibrate the transmission matrices of the scattering medium. We demonstrated that a user-specified pattern can be generated after the scattering medium using the virtual transmission matrices. Our method does not rely on the memory effect of the scattering medium and is effective for a strong scattering medium. Our work is expected to be applied in structured light illumination or coherent control. (C) 2019 Optical Society of America