Tripling Optical Storage With New Encoding Approach

Purdue University innovators have created technology aimed at replacing Morse code with colored “digital characters” to modernize optical storage. This will allow more data to be stored and for that data to be read at a quicker rate. Rather than using the traditional dots and dashes as commonly used in these technologies, the Purdue innovators encode information in the angular position of tiny antennas, allowing them to store more data per unit area.

This technology can also be used for security tagging and cryptography.

Above – The proposed anisotropic metasurface from Purdue University innovators has significant potential for high-density optical data storage, dynamic color image display, and encryption.

“The storage capacity greatly increases because it is only defined by the resolution of the sensor by which you can determine the angular positions of antennas,” said Alexander Kildishev, an associate professor of electrical and computer engineering in Purdue’s College of Engineering. “We map the antenna angles into colors, and the colors are decoded.”

Laser and Photonics Review -Enabling Optical Steganography, Data Storage, and Encryption with Plasmonic Colors

Plasmonic color generation utilizing ultrathin metasurfaces as well as metallic nanoparticles holds a great promise for a wide range of applications including color displays, data storage, and information encryption due to its high spatial resolution and mechanical/chemical stability. Most of the recently demonstrated systems generate static colors; however, more advanced applications such as data storage require fast and flexible means to tune the plasmonic colors, while keeping them vibrant and stable. Here, a surface‐relief aluminum metasurface that reflects polarization‐tunable plasmonic colors is designed and experimentally demonstrated. Excitation of localized surface plasmons encodes discrete combinations of the incident and reflected polarized light into diverse colors. A single storage unit, namely a nanopixel, stores multiple‐bit information in the orientation of its constituent nanoantennae, which is conveniently retrived by inspecting the reflected color sequence with two linear polarizers. Owing to the broad color variability and high spatial resolution of the metasurface, the proposed encoding approach holds a strong promise for rapid parallel readout and encryption of high‐density optical data. The method also enables robust generation of dynamic kaleidoscopic images without the “cross‐talk” effect. The approach opens up a new route for advanced dynamic steganography, high‐density parallel‐access optical data storage, and optical information encryption.

SOURCES – Purdue University, Laser and Photonics Review
Written By Brian Wang,