Wavelength-multiplexed diffractive optical storage enables massively parallel image retrieval
The Californer/10351525

LOS ANGELES - Californer -- The explosive growth of data generated by artificial intelligence, cloud computing, and modern digital infrastructures is placing increasing pressure on existing information storage technologies. Although magnetic storage systems such as hard disk drives remain the dominant platform for digital storage, they face challenges including rising costs, limited lifespan, and relatively slow information retrieval. To address these challenges, researchers at the University of California, Los Angeles (UCLA) have developed a new optical information storage platform that uses engineered diffractive structures to store and rapidly retrieve thousands of images.

The UCLA team introduced a wavelength-multiplexed diffractive optical storage system composed of multiple passive dielectric layers that are spatially engineered using deep learning. Instead of storing information electronically, the system stores thousands of distinct images in a compact stack of diffractive layers, densely packed within a transparent material. Each image is assigned a unique illumination wavelength, enabling information to be selectively retrieved simply by changing the wavelength of the incident light.

More on The Californer

• NYC Banners Delivers High-Stakes UN General Assembly Backdrop for the US Department of State Event
• Om Mushrooms Says "don't F*** With My Coffee" With New Focus Lion's Mane Coffee Booster
• OneVizion Appoints Energy Infrastructure Executive Walt Farrell to Board of Directors
• Tampa Bay Reporter Launches with a Mission to Deliver Local News with National Reach
• AAEOY Awards Honor Asian American Engineering and Technology Leaders in Silicon Valley

Similar to tuning a radio to different stations, illuminating the diffractive structure with different wavelengths reveals different stored images, all projected onto the same output field of view. Wavelength-multiplexed diffractive optical storage offers a robust, high-density solution that is particularly vital for the long-term, stable archiving of massive datasets. By eliminating mechanical components and the degradation risks associated with traditional magnetic media, this technology ensures the reliable preservation and rapid access to information over extended periods.

Through numerical simulations in the visible spectrum, UCLA researchers demonstrated that their diffractive storage platform could store and reconstruct more than 4,000 independent image patterns while maintaining high image fidelity and minimal interference between wavelength channels. The reconstructed images exhibited an average peak signal-to-noise ratio exceeding 48 dB, highlighting the high quality of the retrieved information.

More on The Californer

• Prime Mount Launches Professional TV Mounting Services in Sacramento, CA
• "JACKIE the STRIPPER," Starring Charlotte Kirk and The PUSSYCAT DOLLS' Kimberly Wyatt, Now Streaming on PRIME
• California: Governor Newsom signs bills to protect sexual assault survivors and increase safety on college campuses
• Governor Newsom signs legislation to accelerate California's fusion industry, announces major investment for quantum research
• California: Governor Newsom signs historic law to stop big business from shutting out competition, cuts red tape to speed up business permitting

To experimentally validate the concept, the team fabricated a proof-of-concept two-layer diffractive device and demonstrated the storage and retrieval of six different image patterns. By sequentially illuminating the device with six wavelengths ranging from 500 nm to 740 nm, the researchers successfully reconstructed six distinct images within the same output field of view, confirming the feasibility of wavelength-encoded optical storage in a physical system.

Importantly, the proposed architecture is highly scalable and can operate across different regions of the electromagnetic spectrum without relying on complex material dispersion engineering. Furthermore, the wavelength-multiplexing strategy can be combined with other optical multiplexing approaches, such as polarization, illumination angle, or spatial shifting, to increase storage capacity further.

The study was supervised by Professors Aydogan Ozcan and Mona Jarrahi of UCLA. The other authors of this work include Che-Yung Shen, Yuhang Li, Cagatay Isil, Jingxi Li, Leon Lenk, Tianyi Gan, Guangdong Ma, and Fazil Onuralp Ardic of UCLA.

Article: https://doi.org/10.1117/1.AP.8.4.046011