Active spectral filtering through turbid media

We demonstrate controlled wavelength-dependent light focusing through turbid media using wavefront shaping. Due to the dispersion caused by multiple light scattering, light propagation through turbid media can be independently controlled between different wavelengths. Foci with various wavelengths can be generated by applying different optimized wavefronts to a highly scattering layer. Given the linearity of the transmission matrix, multiple foci with different wavelengths can also be simultaneously constructed.