Multicolor Wavefront Shaping

Wavefront shaping allows for controlling light propagation and optical processes in otherwise opaque media. Wavefront shaping was invented in 2007 at COPS [1], [2] and has since found many uses in e.g. nanophotonics, cryptography [3] and biomedical imaging. A new challenge in wavefront shaping is control of multiple incident wavelengths. Normally, when an opaque sample is illuminated with plane waves of different wavelengths, each wavelength forms its own random speckle pattern, as illustrated in figure 1a. The scattering process for different wavelengths becomes independent if the wavelengths differ by more than the correlation bandwidth [4]. This means that each wavelength must be shaped independently, as illustrated in figure 1b, leading to a massive increase in complexity.