Can 200 TB Optical Discs Replace Hard Drives? Inside China’s 3D Nano‑Storage Breakthrough

Chinese Researchers Unveil 200 TB Optical Disc Breakthrough

Note: China’s new technology is resurging, though it may not see commercial use for some time.

According to reports from CCTV and other media, Chinese scientists have developed a new technology that could enable optical discs capable of storing 200 TB of data.

If commercialized, this product could revive optical media as an economical, efficient alternative to current hard drives or magnetic tapes for long‑term storage.

Researchers from Shanghai University of Science and Technology (USST) and the Shanghai Institute of Optics and Fine Mechanics (SIOM) report that by stacking hundreds of optical storage layers they can reach petabyte‑scale capacities, claiming to have broken the diffraction limit that restricts recording feature density.

Published in Nature under the title “3D Nano‑Scale Optical Disc Memory with Petabit Capacity,” the team describes a novel storage medium called dye‑doped photoresist (DDPR) that incorporates aggregation‑induced emission (AIE‑DDPR).

When used as a recording layer, the medium reportedly achieves surface densities far superior to other optical systems and hard‑drive technologies—about 125× that of gold‑nanorod multilayer discs and 24× the best hard drives recorded in 2022.

The recording and retrieval processes each require two laser beams: a 515 nm femtosecond Gaussian beam and a 639 nm continuous‑wave ring beam for writing, focused on the recording region.

Technically, the first beam initiates polymerization, while the second deactivates it, creating sub‑diffraction‑limited recording points. Reading uses a 480 nm pulsed laser and a 592 nm continuous‑wave laser.

The researchers note that blank discs coated with AIE‑DDPR can be fabricated using standard DVD processes, including spin‑coating and disc formation.

During testing, the AIE‑DDPR film proved so transparent that up to 100 layers could be written and read, with inter‑layer spacing of just 1 µm.

Data written into alternating USST and SIOM layers showed clear, alternating patterns on both even and odd layers without crosstalk, and deeper layers maintained resolution comparable to the top layers.

With 100 layers, a minimum spot size of 54 nm, and a track pitch of 70 nm, the team estimates a capacity of 1.6 Petabit (≈200 TB) within a DVD‑sized area.

Researchers caution that, despite the dramatic increase in surface density, commercial viability requires faster write speeds and improved energy efficiency, potentially achievable with higher‑repetition‑rate femtosecond lasers and more sensitive photoresists.

This means the nano‑optical storage system is still some distance from market‑ready drives and media, though it could eventually offer lower costs than current high‑end optical libraries and hard‑drive arrays, meeting the massive data‑storage demands of the AI era.

They also argue that flash and hard‑drive technologies impose high energy burdens, leading to elevated operating costs and short lifespans, whereas optical media can safely store data for decades without degradation.

However, some reports suggest that for archival purposes this technology may not significantly outperform conventional magnetic tape; IBM’s 2023 TS1170 tape drive, for example, stores up to 150 TB (compressed) on a 50 TB cartridge.