An apparatus includes a first storage cell with an electrical property. The first storage cell is configured to change the electrical property in response to a first light energy, and to maintain the change to the electrical property. The first storage cell is also configured to alter the change to the electrical property in response to a second light energy, and to maintain the alteration to the change to the electrical property. A second storage cell disposed over the first storage cell in a vertical plane of the first storage cell. A third storage cell disposed adjacent to the first storage cell in a horizontal plane of the first storage cell.

Provided herein are compounds for use as photochromic molecular switches having very long thermal isomerization half-lives and switchable fluorescence properties both in solution and the solid state.

An integrated optical transmission element may be provided. The integrated optical transmission element includes an optical cavity including an input port and an output port, and photorefractive material within the optical cavity. A transmission of light from the input port to the output port is persistently changeable by an optical control signal provided to the photorefractive material, the optical control signal being configured to change a refractive index.

An integrated optical transmission element may be provided. The integrated optical transmission element includes an optical cavity including an input port and an output port, and photorefractive material within the optical cavity. A transmission of light from the input port to the output port is persistently changeable by an optical control signal provided to the photorefractive material, the optical control signal being configured to change a refractive index.

Provided herein are compounds for use as photochromic molecular switches having very long thermal isomerization half-lives and switchable fluorescence properties both in solution and the solid state.

A data storage medium for storing digital data. The medium includes a mixture of different nano-sized materials, each of the nano-sized materials having a respective optical transition profile characterizing an optical transition of the nano-sized material and covering a respective wavelength range, wherein a combined optical transition profile of the mixture covers an extended wavelength range as compared to the respective wavelength ranges of the respective optical transition profiles of the different nano-sized materials, and wherein one or more of the different nano-sized materials is photo-reactive to selectively vary a respective absorption/emission band upon irradiation to encode digital data in the combined optical transition profile of the mixture.