Silex claims silicon "optical gain" is a first

LUCAS HEIGHTS, New South Wales, Australia -- Translucent Photonics Inc., a Palo Alto, California, based subsidiary of Australian research company Silex Systems Ltd., has achieved room temperature "optical gain" in silicon, Silex said Tuesday (November 11, 2003).

Silex did not fully explain what was meant by the term optical gain, but one interpretation is that Translucent has shown the ability to make a laser light emitter in conventional crystalline silicon.

"Translucent's invention enables, for the first time, the possibility of integrating optical telecommunications and electronic processing in conventional silicon chips. For example, this could make optical 'Fiber-to-the-Home' a real medium-term possibility, rather than a long-term dream," said Michael Goldsworthy, Silex chief executive officer, in a statement.

Silex claimed in its press release that, for the first time, optical gain has been demonstrated at room temperature in the same form of silicon that is used to make integrated circuits.

"While others have demonstrated optical gain at cryogenic temperatures or in amorphous materials that are not usable for today's electronics, Translucent has demonstrated the first room temperature optical gain in semiconductor-grade silicon. This enables optics to tap into the existing electronics and silicon processing infrastructure," said Robert Byer, a professor of the applied physics at Stanford University, after visiting Translucent's laboratory and reviewing the project results, as reported by Silex.

Several other teams have investigated the light emitting properties of silicon, including STMicroelectronics and the recently funded Si-Light Technologies Ltd. (see November 4 story)

Translucent's Palo Alto laboratory was funded by Silex through an initial investment in April 2001. In September 2003 Silex announced it had moved from 30 percent ownership to 73 percent ownership of Translucent, in consideration of further funding and Silex shares.

The second tranche of funding is geared to additional technical and commercial milestones related to the demonstration of early-stage prototype devices with industrial performance criteria. Meeting these new milestones within the next two years is expected to take Translucent through to positive cash flow without additional investment, Silex said.

Silex itself is researching isotopically-pure silicon and uranium-enriched silicon and signed an R&D collaboration agreement with wafer maker Sumitomo Mitsubishi Silicon Corp. in 2002 (see December 10, 2002, story).