Electrical modulation of diffractive structures

We present an experimental demonstration of two new methods for electronically modulating diffractive structures. The first involves the creation of periodic displacement of a liquid-air interface by application of a spatially modulated electric field produced by an array of electrodes. The second method also uses an electrode array but creates a diffraction grating by selectively attracting and repelling electrophoretic particles in a dielectric fluid. Potential areas of application of these techniques include controllable holography and wavelength division multiplexing.