Free space optics poised for a comeback?https://www.ptc.org/ptc12/newsletter/pdf/cdptcday32012.pdf
Free space optics poised for a comeback?
The nearly forgotten technology of free space optics—effectively laser-enabled communication through the air without a fibre enclosure—may be poised for a comeback.
Free space optics enjoyed a brief flurry of hype at the turn of the century when a former AT&T Wireless CEO, Dan Hesse, took the helm of Seattle-based start-up Terabeam with the promise of using the tech to take on the established fixed telcos at broadband communication.
The promise of free space optics seemed great at the time. It avoided all the costs of fibre optic trenching and ducting as well as spectrum licensing costs because it used unregulated light waves. But the tech had one major weakness in its propagation: constant laser light is affected by fog and other adverse atmospheric conditions as rain and snow. This held back adoption to the mass market and the technology was relegated to the margins, used only in niches such as primary service back-up and military applications.
Now New Jersey company Attochron claims to have a technological fix: the use of affordable and smallsized short-pulsed lasers. Company investor CJ Davies and adviser Matthew Lampros told CommsDay at PTC’12 that an ultrashort laser pulse – with a pulse duration at least a million times shorter than previous lasers —exhibits different behavior than previous FSO systems, even at the same wavelength of 1550nm.
“Attochron and its partners have proven that unique ultrafast optical techniques will allow the signal to penetrate fog and clouds many times better than existing systems,” the firm says. According to Lampros, the concept of pulsed lasers is not new. “But they were too big in size for communications applications. Now they are small they are viable.” Davies says that the laser units in development are about the size of a briefcase and can transmit gigabit levels of data at around three kilometres.
Lampros says the company is at pains not to over-hype its development, positioning the tech not as a fibre replacement but more a “bridging apparatus,” for example, in bringing gigabit capacities quickly to cellular backhaul or in providing fibre-type services where the terrain is too difficult to dig trenches.
But the economics of free space seem more compelling than that: free space optics stallations cost around US$30,000 per mile compared with up to a million dollars per mile for fibre installation, says Davies. Attochron claims to have thoroughly tested the technology at the Picatinny Arsenal military facility in New Jersey and demonstrated it to Lockheed Martin, the US Airforce and JDSU. Now, says Lampros, the company is ready to approach manufacturers for licensing and investors for more capital. Additionally, Australian submarine cable consultant and former Telstra executive, John Hibbard, has signed on as a company director.