Posted on 02/26/2025 6:21:53 AM PST by ShadowAce
Researchers have developed a new type of photochromic glass that can store and rewrite data indefinitely.
By embedding magnesium and terbium, they’ve created a material that changes colors under different wavelengths of light, allowing for high-density, long-term storage without power. This breakthrough could revolutionize data preservation.
For years, scientists have explored the potential of glass as a long-term data storage medium, drawn to its ability to preserve information for eons without requiring power. One promising candidate is photochromic glass, a special type of glass that changes color when exposed to different wavelengths of light. Now, researchers have developed a doped photochromic glass that can potentially store and rewrite data indefinitely, according to a study published today (February 26) in ACS Energy Letters.
A familiar example of photochromism can be seen in certain eyeglasses that darken in sunlight and return to a clear state indoors, a process known as reversible photochromism. Similarly, some photochromic glass materials can change color based on specific wavelengths of light, making them an appealing, cost-effective option for high-density data storage. However, the challenge lies in not just encoding information but also being able to erase and rewrite it repeatedly.
Now, a research team led by Jiayan Liao, Ji Zhou, and Zhengwen Yang has made significant progress by developing reversible, tunable patterns in photochromic gallium silicate glass, bringing this futuristic technology one step closer to reality.
A new type of glass that’s etched with a bird design appears differently when exposed to different lasers. Credit: Adapted from ACS Energy Letters 2025, DOI: 10.1021/acsenergylett.5c00024
The team first designed gallium silicate glass modified with magnesium and terbium ions by using a process called doped direct 3D lithography. Liao and the team used a green 532-nanometer (nm)-wavelength laser to inscribe 3D patterns into tiny slabs of the doped glass.
The intricate patterns, randomly chosen dots, symbols, QR codes, geometric prisms, and even a bird, appear purple in the transparent glass, which turns other colors when excited at precise wavelengths. Terbium luminesces green when excited by a deep violet 376 nm laser, and magnesium luminesces red in the presence of violet light at 417 nm.
Then, to fully erase the patterns without changing the structure of the glass, the team applied heat at 1022 degrees Fahrenheit (550 degrees Celsius) for 25 minutes.
Furthermore, the researchers consider the use of magnesium and terbium groundbreaking for their abilities to luminesce at distinctly different wavelengths, which makes it possible to get a tunable, multicolor readout of 3D patterns from a single material. The new approach could be used for high-capacity, stable 3D optical memory storage, and encryption in industrial, academic, and military applications.
Reference: “Direct 3D Lithography of Reversible Photochromic Patterns with Tunable Luminescence in Amorphous Transparent Media” 26 February 2025, ACS Energy Letters.
DOI: 10.1021/acsenergylett.5c00024
It remembers everything but only if you keep it in the dark?
It would seem appropriate.
You may already know this, but the 8-inch floppy disk was developed to provide instruction microcode for the IBM Sys/370. Right after power up, that computer would read from an 8-inch floppy just behind the front panel in order to retrieve the instruction set's microcode. It did not just emulate a 1400 Series machine, it became a 1400 series machine when that floppy was in place. Normally, the 360/370 instruction set floppy was in there.
The Xebec Company licensed the technology from IBM and then made the first commercially available floppy drive system. Those were initially targeted for PDP-8 and PDP-11 computers. Digital Equipment Corporation didn't let that stand for long.
When we were mothballing an older IBM system, we opened one of the cabinets for the disk drives and I took out a few parts, like the hard drive itself, and kept them.
Hey there, self! IBM licensed that drive from Xebec!!!
An interesting theory which is far from usefulness or practical application.
I still have some “punch cards” with one of our accounting programs on them.
I feel old, when I started out working for the fed/gov manual typewriters were our tech. Data storage was a file cabinet and the copier was called carbon paper. Constantly changing ribbons lots and lots of whiteout. Thinking back I have no idea how we did it.
We were mesmerized when the first electric typewriters showed up.
I remember those from my long ago younger days.
I was in awe of this ‘new’ technology!
I remember thinking, “No more tapes!”................
Now I am jealous. I seem to have discarded my cache of punched cards. My paper tape is nowhere to be found either.
I can remember the IBM Selectric was a "jaw dropper".
The rarest rare Earth is Thulium (#69). It is also the most useless. The rare Earths tend to have similar chemical properties so a rare one like Thulium has little in the way of special properties . Typically another rare Earth can be used instead for less money.
Oops! I forgot about Promethium (#61). With a half maximum half life of only 2 years there is little to none on Earth at any given moment.
Tequila does the same only faster..............
I remember one time when the consultant running our computer stuff off site reported one morning to the senior accountant that certain reports, expected to be run overnight, were not ready “because the air conditioning went out”.
When the air conditioner quit the humidity in the computer room grew and at some point the card readers stopped feeding the paper cards through. The young man who started the job had left to get some rest and returned in the morning to find the air con off, the machines idle, and the job not done.
They were waiting for an HVAC outfit to get the air conditioning running again before restarting the computer job.
I remember those from my long ago younger days.
I was in awe of this ‘new’ technology!
I remember thinking, “No more tapes!
—
and I ... no more punch tapes
I remember reading the want ads as a teenager in Jacksonville and there were dozens of ads for ‘KEY PUNCH OPERATORS NEEDED!’
I didn’t know what that was, but I assumed it was a good job for a lifetime!...............
bkmk
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