ROBERT SIEGEL: NPR's Dan Charles has more.
DAN CHARLES: Ten years ago, Elizabeth Downing was working at a company in Silicon Valley, talking with a friend of hers about how one might create a genuine three-dimensional display. People were already able to create the illusion of three dimensions on a flat screen - those 3-D movies, for example, that require special glasses, or holograms. But Downing and her friend wanted to display a model of a physical object in real three-dimensional space so you could walk around it and look at it from any angle. This might be possible, they thought, with invisible laser beams that created a glowing spot where they crossed. Lasers by themselves, it turned out, didn't work.
ELIZABETH DOWNING: You know, I started thinking about it for a while, and I thought, well if you had some medium that would, you know, absorb one wavelength and then absorb the other wavelength and then they could kind of add up the energy inside this magic material and spit out something visible at the point of intersection, well then all you would have to do is scan it around to draw 3-D images. And it just seemed like such an obvious thing to do, so obvious like why hasn't it been done before?
CHARLES: The basic idea had been thought of before back in the 1970s, but scientists then didn't have the lasers and materials that were needed to make it work. They do exist now in various scientific laboratories, and Downing set about assembling them. She became a graduate student at Stanford University, but when she applied for research funding for her project the university turned her down.
DOWNING: I cried. I called up one professor- another professor of mine, and I was in tears, and he said, ``Oh, don't let it bother you. It's nothing personal. Most of mine get rejected, too. Write another one.'' So I did.
CHARLES: Eventually, the Navy gave her some money. In her lab at Stanford, Downing was able to demonstrate the basic idea - two low-energy laser beams crossing each other inside a crystal containing the rare element crasiodimium [sp] created a glowing spot. The crasiodimium was absorbing the energy from the two lasers and releasing that energy in a burst of reddish light. Physicists call this ``up-conversion'' [sp] and Downing knew that some of the world's leading experts on up-conversion worked just down the road at IBM's Almaden research center.
DOWNING: I got a hold of this guy named Roger McFarlane [sp], who's a real famous up-conversion spectroscopist physicist. He's just- you know, everybody all over the world who works in this field knows who he is. And I called him up and I said, ``Hey, you don't know me, but here's- I'm so-and-so and here's what I'm trying to do, and I did it last night in this crystal of, you know, crasiodimium and you got any samples?''
CHARLES: McFarlane did have some samples. He also helped to find other materials that would generate blue light. Eventually, Downing persuaded another Silicon Valley company to donate the lasers she needed to create green light. This meant she could generate all three primary colors, which should eventually allow her to mix those primary colors and produce every shade of an artist's palette. By the end of December, Downing had her display up and running - a block of glass about the size of a sugar cube displaying simple moving lines in three colors.
DOWNING: I could draw three-dimensional images, wire frames. I could do surface areas. I could do- if I scan really fast, I could do little cubes, little volumes inside my little cubes. And then I felt very good about things.
CHARLES: The future for this device is huge, Downing says, and she's help set up a company to turn her experiment into a commercial product. Downing imagines a big block of glass, maybe a yard thick, displaying the airspace around a big airport with airplanes taking off and landing and a storm front approaching. It could also display data collected by CAT scans and MRI machines, creating an image in light of what's going on inside the body.
DOWNING: A team of doctors can sit down, you know- four or five or six doctors can, you know, sit down around this device and interact with the information that's being displayed. Everybody could have a little cursor that they're moving around and pointing at something, just like on your computer display.
CHARLES: These glowing images may be ideal, in fact, for medical purposes, where people want to be able to see not just what's on top, but all the way through. Steven Benton [sp], a researcher at the Massachusetts Institute of Technology's media lab, says it's not so good though for displaying solid objects like buildings or landscape or people walking around.
STEVEN BENTON, Host:
Everything will be transparent, you know. You'll- everybody will look like Casper the Ghost. You can see everybody else through them because, while these spots are glowing, they don't absorb the light from whatever is behind them the way normal solid objects do.
CHARLES: This is Dan Charles in Washington. Transcript provided by NPR, Copyright NPR.