NASA Langley Research Center has developed a novel approach for a high-density optical data storage system to advance the typical capabilities of an optical data storage system. Operating at any laser wavelength from infrared (IR), visible, ultraviolet (UV), and X-ray regimes, the NASA technology utilizes special beam focusing techniques to achieve extremely short focal lengths and ultra-small spot sizes. The technology could be used with any laser wavelength and soft X-ray regime, and can be adapted to take advantage of any optical media. The high-density data storage capability is solely a function of the reduced laser/X-ray spot size.
This NASA technology is based on two known methods to manage beam focal length and spot size using interference methods. In one of those focusing methods, the micro zone plate lens is constructed of an electro-optically active material that changes its index of refraction with applied voltage, thus creating what is essentially a programmable micro zone plate lens with active control of the focal length/focal point spot size. Micro zone plates are used commercially in applications such as soft X-ray microscopes. The other beam focusing method, referred to as the Photonic DART method, was also developed at NASA. It uses novel variations of the micro zone plate approach with varying heights of the rings, and is able to achieve an even smaller spot size using a destructive interference ring pattern that is optimized with diffraction limit.
The technology can be used with dyebased optical media, phase change media, or photoluminescent media. Potential applications include CD and DVD data storage systems, and any system requiring optical read or write with ultra-small spot size.