Electrically-switchable, polarization-independent diffraction grating based on negative dielectric anisotropy liquid crystal

An atomic force microscope is used to scribe polymer-coated substrates to create an electrically-controlled polarization grating. The grating is nondiffracting in the voltage-off state and diffracting in the voltage-on state. Based upon an optical phase difference of approximately π between adjacent pixels, the grating’s efficiency is independent of optical polarization and can be prepared for diffraction in either one or two dimensions.