Skip to Content

Holographic Memory

How holographic data storage works.

Stackable storage. It’s the ultimate space saver, making order out of chaotic cabinets, closets, attics and garages. But until recently it had not made its way into the realm of computers, where megabytes of data are scattered on the face of a disk like millions of shoes across a bedroom floor. Now a few big-name media makers, including Lucent Technologies and IBM, are making important strides in developing optical holography, which stacks information throughout the thickness of a storage medium, instead of just writing it to the surface.

Holographic storage relies mainly on laser light and a photosensitive material-usually a crystal or a polymer-to save data. It works by splitting a laser beam in two. One beam contains the data and is referred to as the “object beam”; the other holds the location of the data and is known as the “reference beam.” The two beams intersect to create an intricate pattern of light and dark bands. A replica of this so-called interference pattern gets engraved three-dimensionally into the photosensitive material and becomes the hologram. To retrieve the stored data, the reference beam is shone into the hologram, which refracts the light to replicate the data beam.

The holographic technique packs data so tightly that one 12-centimeter disk could eventually hold a terabyte of data-about as much information as 200 DVDs. What’s more, holographic storage opens the possibility of reading and writing data a million bits at a time, instead of one by one as with magnetic storage. That means you could duplicate an entire DVD movie in mere seconds.

The idea of storing tons of data three-dimensionally was first proposed by Polaroid scientist Pieter J. van Heerden in the 1960s. But developing the technology was difficult, because the required optical equipment was large and expensive. A typical laser back then, for example, was two meters long. Today, lasers are measured in mere centimeters and are much cheaper.

Holographic storage equipment is not yet produced commercially, but the technology has the potential to spawn new devices and systems. It could supplant DVDs, allow people to save information on 3-D disks, and enable researchers to sift through enormous databases in the blink of an eye. The future may not be that far off, either. Recently, Lucent launched a new venture, InPhase Technologies, to develop holographic storage, and plans to have a product on the market in a couple of years.

Keep Reading

Most Popular

Large language models can do jaw-dropping things. But nobody knows exactly why.

And that's a problem. Figuring it out is one of the biggest scientific puzzles of our time and a crucial step towards controlling more powerful future models.

OpenAI teases an amazing new generative video model called Sora

The firm is sharing Sora with a small group of safety testers but the rest of us will have to wait to learn more.

Google’s Gemini is now in everything. Here’s how you can try it out.

Gmail, Docs, and more will now come with Gemini baked in. But Europeans will have to wait before they can download the app.

This baby with a head camera helped teach an AI how kids learn language

A neural network trained on the experiences of a single young child managed to learn one of the core components of language: how to match words to the objects they represent.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.