1.8-W Diode to Pump Fiber Amplifiers

Kevin Robinson

Researchers at Australian National University have created a high-power 980-nm diode laser specially designed to pump the erbium-doped fiber amplifiers crucial to high-bandwidth short-haul optical telecommunications networks. The laser's 50-µm-wide stripe boasts 1.8 W of peak power, which should be useful for pumping fiber amplifiers in wavelength division multiplexing (WDM) fiber optic networks.

"WDM systems require higher pump powers to be able to amplify signals transmitted through the fiber systems simultaneously at different wavelengths," explained Chennupati Jagadish, head of the department of electronic materials engineering at the university. "This has increased the demands on pump lasers. Increased output power from 980-nm lasers is crucial for high-speed communications systems."

The laser's higher power is due to carefully managing the manufacturing process -- metallorganic chemical vapor deposition -- to reduce the impurities in the semiconductor's epitaxial layers. Jagadish said that researchers also have improved the manufacturing process to reduce the catastrophic optical damage to reflective facets in the laser that shortens the life span of conventional diode lasers.

Researchers from the Australian National University display one of their microscopic high-power quantum-well lasers mounted on the head of a common straight pin.

Semiconductor lasers' main failure mechanism is based on facet damage caused by high optical density. The remedy for this requires protective facet coatings that avoid, for example, laser facet oxidation.

The development is the product of roughly 10 years of effort in Jagadish's department, which was established to help give Australia a leg up in the technology sector. Jagadish estimates the market for pump sources for erbium-doped fiber amplifiers at about $300 million and growing at about 50 percent each year. The university has launched a company, Acton Lasers, to wrap up development and to set up manufacturing processes for this and other devices it is producing.

Yuh Chen Group from Taiwan is a potential investor in the fledgling company. "Yuh Chen Group is keen to develop strategic relations with [the university's] research group for developing the blue-green end of optoelectronic device technologies," Jagadish said, "... and has expressed interest in establishing a research and development laboratory in Canberra."

Before the laser is commercialized, it must be tested for reliability to estimate its lifetime. Jagadish expects the company to begin producing the laser commercially in a year.