Temporal color mixing and dynamic beam shaping with silicon metasurfaces

A dynamic metasurface in the mix Metasurfaces have been designed and fabricated to function as many passive optical elements. A time-dependent active element can now be obtained by marrying concepts in microelectromechanics with an array of one-dimensional dielectric nanowires. Although such a static array has been used to select for desired wavelengths, the wavelength is dependent on the nanowire-to-substrate separation. Holsteen et al. added a voltage-controlled actuation element to the design that could steer light beams as well as select and mix certain colors. The fast actuation capability could affect applications ranging from autonomous vehicles to augmented and virtual reality systems. Science , this issue p. 257