The birth of "super optical disk" marks a breakthrough in my country's optical storage field

Recently, the Shanghai Institute of Optics and Precision Mechanics of the Chinese Academy of Sciences (hereinafter referred to as "Shanghai Institute of Optics and Fine Mechanics") cooperated with Shanghai University of Technology and other scientific research institutions to make breakthrough progress in the research of ultra-large capacity three-dimensional super-resolution optical storage. The research team used the world's first dual-beam controlled aggregation-induced emission super-resolution optical storage technology to experimentally break through the diffraction limit for the first time in both information writing and reading, and achieved super-resolution data storage with a point size of 54nm and a track spacing of 70nm. It also completed 100 layers of multi-layer recording, and the equivalent capacity of a single disk reached the Pb level, which is of great significance for my country to break through the "stuck neck" obstacles in the field of information storage and achieve sustainable development of the digital economy. The relevant research results were published in the journal Nature on February 22, 2024.

Optical storage technology has the unique advantages of being green, energy-saving, safe and reliable, and having a lifespan of 50 to 100 years. It is very suitable for long-term and low-cost storage of massive data. However, due to the limitation of the diffraction limit, the maximum capacity of traditional commercial optical discs is only in the hundreds of GB level. In the era of big data with growing information volume, breaking through the diffraction limit, reducing the size of information points, and increasing the storage capacity of a single disc have long been the unremitting pursuit of the optical storage field.

In 1994, German scientist Professor Stefan W. Hell proposed stimulated emission depletion microscopy, proving for the first time that the optical diffraction limit could be broken, and won the Nobel Prize in Chemistry in 2014. After more than 20 years of development, optical super-resolution has been achieved in many fields such as microscopic imaging and laser nanolithography, and super-resolution writing of information has been solved. However, traditional dyes are prone to fluorescence quenching in an aggregated state, resulting in information loss. At the nanoscale, there is also the problem of being obliterated by background noise, making it difficult to read super-resolution information. The readout method usually relies on electron microscope scanning, which limits the application of super-resolution technology in the field of optical storage. Therefore, the development of media that can simultaneously achieve super-resolution writing, super-resolution reading, three-dimensional storage and long-lifetime media has been a problem that needs to be solved in the field of optical storage research for more than 10 years.

Since the 1980s, Academician Gan Fuxi of the Shanghai Institute of Optics and Fine Mechanics has pioneered the research of digital optical disc storage technology in my country, and the team of the Shanghai Institute of Optics and Fine Mechanics has been deeply engaged in the field of optical storage. Relying on a rich research foundation and innovative technical solutions, based on the combination of dual-beam super-resolution technology and aggregation-induced emission photoresist materials, the diffraction limit has been broken in both information writing and reading, and super-resolution data storage with a point size of 54nm and a track spacing of 70nm has been achieved. 100 layers of multi-layer recording have been completed, and the equivalent capacity of a single disc is about 1.6Pb. After accelerated aging testing, the optical disc medium has a lifespan of more than 40 years, and the fluorescence contrast is still as high as 20.5:1 after accelerated repeated reading. This is the first time in the world that ultra-large capacity optical storage at the Pb level has been achieved.

From optical microscopy technology to today's "bottleneck" lithography machines, to optical storage technology, all are limited by the optical diffraction limit. Among the 125 most cutting-edge scientific problems in the world released by Science in 2021, breaking through the diffraction limit ranks first in the field of physics. The successful development of this super-resolution optical disc has broken through this physics problem in both information writing and reading, which will help my country break through the "bottleneck" obstacles in the field of storage, and will play a major role in the big data digital economy to meet the major needs of the information industry.

In the future, the research team will accelerate original innovation and key technology research, promote the integration and industrialization of ultra-large-capacity optical storage, and expand its cross-application in the fields of microscopic imaging, lithography, sensing, and optical information processing to produce more and better innovative results.