A Glimpse of a Future in a New Kind of Light

How many scientists does it take to change the light bulb?

It’s not a joke. The ubiquitous light bulb is quietly on its way to becoming as quaint a relic as the gas lanterns it replaced more than a century ago. Incandescent bulbs, neon tubes and fluorescent lamps are starting to give way to light-emitting microchips that work longer, use less power and allow designers to use light in ways they never have before.

By BARNABY J. FEDER NY Times

The chips — 18 million of them — are already on display in the $37 million Nasdaq sign in Times Square. They are in the vibrant facade of the Goodman Theater in Chicago and adorned last year’s White House Christmas tree. More notable, the chips are penetrating blue-collar tasks like illuminating traffic lights, brake lights and exit signs.

Lighting experts expect the pace of change to pick up as researchers continue their relentless efforts to shrink the chips to microscopic size, improve their already impressive energy efficiency and increase their brightness. The chips are expected to move into the general home and office lighting market as early as 2007.

The eventual result, the experts say, will be savings of billions of dollars annually in energy and maintenance costs and a revolution in how people use lighting in homes and offices to influence their moods.

"We are not talking about replacing light bulbs," said Arpad Bergh, a former Bell Labs researcher who is president of an industry trade group working with the government to promote the new technology. "We are talking about a totally new lighting industry."

The vision of revolutionary new uses of light reflects the ability of such lighting, also known as solid-state lighting, to switch virtually instantaneously among more than a million shades of color at the command of a computer. Researchers talk about using the technology to coordinate lighting effects in a theater with film scenes, which might make a battle sequence appear to leap off the screen, or to alter the color and brightness of lighting in nursing homes at appropriate times, which could help stimulate or soothe residents.

The chips, which are known as light-emitting diodes, or L.E.D.’s, have huge performance advantages in many mundane tasks. In devices like traffic lights, for example, they consume 80 percent less electricity than do the bulbs they replace and last up to 10 times as long. Moreover, they have the safety advantage of gradually fading instead of unpredictably burning out.

Beyond such obvious benefits, though, it is the ease of mating the chips to computers that is driving interest. Programs simple enough to run on a hand-held personal digital assistant can alter the intensity, pattern and colors produced by solid-state lights. Color Kinetics, a five-year-old lighting company based in Boston, calculates that the various chips it packages with computer controls can generate up to 16.7 million colors.

That flexibility is already used in advertising and entertainment. Solid-state lights are featured in numerous Times Square signs and Broadway shows like "Hairspray." Mad Doc Software, based in Lawrence, Mass., has designed tools to link video games to room lighting so that a player in a Star Trek game who is passing a red nebula would have one side of a room shift in color.

"It’s fantastic how much more immersive the game becomes," said Ian Davis, founder of Mad Doc.

Architects and building designers have far more ambitious possibilities in mind, including mimicking indoors the variability of natural lighting as the day progresses. Lighting experts predict that once costs come down, such flexibility will greatly increase the attention paid to the role of light in people’s moods and health.

"L.E.D.’s are only limited by what we put in the computer," said Fred Oberkircher, director of the Center for Lighting Education at Texas Christian University. "I’m waiting for the day when clouds of light float across my ceiling."

It may sound whimsical, but Mr. Oberkircher’s vision is rooted in research suggesting that people find the rigid lighting environments they normally work and dwell in boring and, in some cases, unhealthy. While most market projections are based on assessing the progress of solid-state lights toward matching the cost and performance of traditional incandescent and fluorescent white lights, some experts say that such comparisons miss the point.

"The ability to do things you couldn’t do before is what will trigger mass adoption," said Michael Holt, president of LumiLeds, a leading diode producer that is a joint venture of Agilent Technologies and Philips Lighting. "People will become much more attuned to the mental and health aspects of light in the next 5 to 10 years."

The chips driving the revolution currently cost too much to use in general lighting. The cost of white-light diodes for standard electrical sockets is anywhere from 40 to 100 times that of comparably bright incandescent bulbs, according to various industry estimates.

But like their cousins the microprocessors, the diode chips are continually improving in performance and plunging in price. They could become cheap and luminous enough to break into the general lighting market as early as 2007, according to a technology road map developed by the Optoelectronics Industry Development Association, the trade group Mr. Bergh heads.

By then, the chips are likely to be facing competition in many specialty applications from a newer form of solid-state lighting known as organic light-emitting diodes, or O.L.E.D’s. These light-emitting plastics are not nearly as bright or durable as the chips but may prove to be more economic for many uses. Like other polymers, they would be manufactured in continuous processes instead of batch by batch the way microchips are made. They are already being used to light small displays, like the battery-life monitor in the Norelco Spectra razor.

Whatever the progress, experts like Mr. Holt and Charles A. Becker, head of the L.E.D. for lighting project at General Electric’s research laboratory, say incandescent bulbs are likely to remain so cheap that they will be widely used for years to come as white-light sources, even though they are quite inefficient and fragile.

Light bulbs, which lighting experts deride as heaters that happen to give off visible light, work by forcing electricity through a metal filament in a vacuum. About 6 percent of the energy ends up as light. Today’s light chips are up to five times as efficient.

Researchers say that further development could double the chips’ efficiency advantage. If achievable, these gains would allow solid-state lighting to surpass the efficiency of fluorescent lamps.

The first practical diode, which emitted low intensity red light, was invented in 1962 at General Electric. Red and amber L.E.D.’s came to market in the 1970’s as on-off signals and other indicators for electronics and machinery. Using diodes for general lighting seemed laughable until researchers at companies like Cree, Nichia Chemical, Toshiba and Hewlett-Packard discovered much brighter materials and relatively inexpensive emitters of blue and green light in the early 1990’s.

Blue diodes were crucial to generating white light, which could be produced by blending the blue, red and green or by shining the blue light through a coating of yellow phosphor. By last year, products built around the new generation of higher-intensity colors and white light had become a $1.2 billion market, according to Dr. Robert V. Steele, director of optoelectronics research at Strategies Unlimited, a market research company in Mountain View, Calif.

The biggest market at the moment is in outdoor signs and in lighting the contours of buildings like fast food restaurants, where the diodes are displacing neon. The nation’s four million or so traffic signals represent a smaller market, but diodes have taken over a third of it and continue to spread rapidly, according to Gary R. Durgin, vice president for business development for Dialight, a solid-state lighting supplier based in Farmingdale, N.J.

Buses, trucks and autos have diodes in brake lights and interior lighting. Styling and maintenance benefits are driving the trend, but there are safety benefits, too. Because the diodes light up fractions of a second faster than do incandescent lights when a driver hits the brakes, anyone trailing a vehicle at 65 miles an hour is able to stop about 19 feet sooner, according to a study at the University of Michigan Transportation Research Institute.

New research fields like nanotechnology are spurring innovation. In July, for instance, Kopin, a manufacturer of semiconductors and electronics displays based in Taunton, Mass., disclosed that it had discovered a way to make millions of pockets just two nanometers thick — the width of just 10 hydrogen atoms — in the dust-size light-emitting chips. The nanopockets, as Kopin calls them, help light escape the chip without being obstructed by microscopic defects in the chip’s crystal structure. The new design cut the voltage needed to get light out of the chips enough to grab the attention of makers of battery-operated electronics.

As a result, Kopin, which was once unknown in the industry, is gearing up to ship 100 million light chips this year to contractors who will package them with power and optical components for use by device manufacturers.

The first applications, according to John Fan, Kopin’s chief executive, are likely to be back-lighting for liquid-crystal displays on portable electronics and night-lighting for keys on devices like cellphones. The chips are so small that the entire year’s production could be easily enclosed in a golf ball.

Mr. Fan and other entrepreneurs have been attracted by the potentially huge environmental and energy returns from replacing traditional lights with solid-state devices. One widely cited study for the Energy Department concluded that the widespread use of solid-state lighting by 2025 could cut electricity demand 10 percent and save consumers $100 billion.

Getting there is not a trivial challenge, though. Researchers say there are numerous hurdles to overcome in fields like manufacturing technology, chip design and extraction of the light created in the chips.

The new technology also requires changes in regulations and standards. For instance, the advertised life of a product line of light bulbs is set as the length of time until half of them fail in tests. But solid-state lighting slowly degrades rather than burning out so the industry is struggling to come up with an agreed standard for "useful life."

While many in the industry are confident about where their markets will end up, the hurdles make it hard to project how they will get there.

"It’s easier to know what will happen 10 years from now than 2," said Mr. Durgin of Dialight.

Copyright 2003 The New York Times Company