Dynamically reconfigurable holograms for generating color holographic images

A method for generating a color holographic image using a hologram, the method comprising:

• converting three-dimensional color holographic image data of a color holographic image into electronic signals using a computing device;
• applying the electronic signals to phase-modulation elements of a phase-control layer and intensity-control elements of the hologram using the computing device, wherein each phase-modulation element is configured to have a selectable effective refractive index for wavelengths in one of three primary color wavelength bands of the visible spectrum, wherein the selectable effective refractive index comprises a negative effective refractive index and wherein each of the of intensity-control elements is configured to have a selectable transparency to control an intensity of light transmitted through a respective intensity-control element of the intensity-control elements,
• addressing the phase-modulation elements and intensity-control elements to produce wavefronts and to control the intensity of light transmitted through the hologram to electronically produce one or more color three-dimensional holographic images;
• and
• transmitting light comprising wavelengths in the primary color wavelength bands through the hologram to generate the color holographic image,
• wherein the phase-control layer further comprises:
• a first layer of approximately parallel nanowires, each nanowire having substantially regularly spaced fingers;
• a second layer of approximately parallel nanowires that overlay the nanowires in the first layer, each nanowire having substantially regularly spaced fingers, wherein the nanowires in the first layer are approximately perpendicular in orientation to the nanowires in the second layer;
• and
• resonant elements at nanowire intersections, wherein each resonant element includes two fingers of a nanowire in the first layer and two fingers of a nanowire in the second layer and one or more adjacent resonant elements form a phase-modulation element.

A system for generating a color holographic image, the system comprising:

• a computing device including a processor and a computer readable medium;
• a dynamically reconfigurable hologram coupled to the computing device, the hologram comprising:
• a phase-control layer having a plurality of phase-modulation elements, wherein each phase-modulation element is configured to have a selectable effective refractive index and selectively transmit wavelengths associated with one of three primary color wavelength bands of the visible spectrum, wherein the selectable effective refractive index comprises a negative effective refractive index;
• an intensity-control layer having a plurality of intensity-control elements, wherein each of the plurality of intensity-control elements is configured to have a selectable transparency to control an intensity of light transmitted through a respective intensity-control element of the plurality of intensity-control elements, wherein one or more color three-dimensional holographic images are produced by electronically addressing the phase-modulation elements and intensity-control elements to produce wavefronts and control the intensity of light transmitted through the hologram;
• wherein the phase-control layer further comprises:
• a first layer of approximately parallel nanowires, each nanowire having substantially regularly spaced fingers;
• a second layer of approximately parallel nanowires that overlay the nanowires in the first layer, each nanowire having substantially regularly spaced fingers, wherein the nanowires in the first layer are approximately perpendicular in orientation to the nanowires in the second layer;
• and
• resonant elements at nanowire intersections, wherein each resonant element includes two fingers of a nanowire in the first layer and two fingers of a nanowire in the second layer and one or more adjacent resonant elements form a phase-modulation element;
• and
• a light source positioned and configured to emit light transmitted through the hologram, wherein the processor converts three-dimensional color holographic image data of a color holographic image stored in the computer readable medium into electronic signals, the computing device applies the electronic signals to the phase-modulation elements and intensity-control elements of the hologram to adjust the selectable effective refractive index of the phase-modulation elements and the selectable transparency of the intensity-control elements such that a viewer perceives the color holographic image.