Organic Lasers Grow in the Lab

You’ve heard of organic fruits and vegetables, but what about organic optical components? Unlike items from the garden, the search for organic lasers is a matter of lowering production costs, rather than producing a healthy diet.

Bell Labs, the research arm of Lucent Technologies Inc. (NYSE: LU), announced a few weeks ago that it has developed the first electrically powered organic laser, a breakthrough that may lead to more widespread use of lasers in various applications, including communications equipment. But don’t get too excited: Commercial applications are still years away.

What is an organic laser? The scientists at Bell Labs grew high-quality benzene crystals to form a molecule called tetracene. This is a very pure and clear crystal that conducts electricity extremely well. When the researchers injected electric current to excite the tetracene to emit light, the light bounced back and forth between mirrors in the material, eventually producing beams of intense yellow-green light.

The biggest benefit of organic lasers is that the material is much cheaper than inorganic semiconductor materials such as gallium arsenide, which is used in lasers today. Previously, researchers had thought organic materials would never be able to carry the high electrical currents needed for lasers, say the Bell Labs scientists. But tetracene is among the purest organic semiconductors and is able to conduct electricity with the necessary properties.

“Organically-based devices are considered to be very low cost and easier to make,” says Ananth Dodabalapur, one of the Bell Labs scientists who worked on the project. “The material is more flexible than inorganic materials.”

While other scientists have built organic lasers powered by light sources, this is the first electrically powered organic laser. The benefit of an electrically powered laser is two-fold: It is more compact, making it easier to employ in integrated electronic circuitry; and it uses less energy. This means that more lasers could be produced much faster and more inexpensively, and they would be smaller and consume less energy in a system. All around, systems vendors using these types of organic lasers would be in a win-win situation, with inexpensive and smaller parts doing the same job as the bigger, more expensive parts used today.

“I think it’s a pretty significant breakthrough,” says Nick Colaneri, director of new technology at Uniax Corp., a member of DuPont Technologies, a company that manufactures devices based on polymers. “People have tried to demonstrate lasing using electronic stimulation before, but they haven’t been able to overcome the challenges. Those of us in this field see this as an important step toward further development in organic component technology.”

But it will be years before the discovery will be used in any sort of commercial application. Because the current configuration of the Bell Labs organic laser operates at a visible wavelength, it’s not yet appropriate for optical communications, says Dodabalapur. Although it’s still too early to nail down what applications will use this technology first, consumer-based products like laser printers and storage technology make sense, he adds.

-- Marguerite Reardon, senior editor, Light Reading, http://www.lightreading.com

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