A new manufacturing process, impressively dubbed as Ultrafast Laser Plasma Implantation (ULPI), might well usher in a new breed of photonic integrated circuits (PICs).
Despite the futuristic name, ULPI is not science fiction. A pilot manufacturing facility, which won funding to the tune of £5.2 million ($7.8 million) last December -- including a £3.7 million ($5.5 million) contribution from the UK's Engineering and Physical Sciences Research Council (EPSRC) -- is being set up at the University of Leeds.
Professor Gin Jose, who works at the Institute for Materials Research in the University of Leeds' Faculty of Engineering, told Light Reading that ULPI was "revolutionary," holding out the promise of greater cost-efficiencies and better performance from optical transport systems.
PICs have, of course, been around for some time. The limitation of electronic integrated circuits in pursuit of more transistors over a single silicon wafer has forced the industry to find an alternative -- cue the PICs.
And suppliers such as Huawei Technologies Co. Ltd. , Infinera Corp. (Nasdaq: INFN) and NeoPhotonics Corp. (NYSE: NPTN) have each got their hands dirty with them as they try to improve the performance of optical networks. Huawei, for example, has developed a PIC that integrates multiple WDM components (lasers, modulators, detectors and multiplexers) to deliver 200 Gbit/s per fiber. The Chinese vendor last year said it was also developing a 400Gbit/s PIC. (See Huawei Ups the Metro Ante, Infinera Targets Data Center Connectivity Market With Metro Platform, Cable Has a PIC Opportunity, Reckons Infinera and NeoPhotonics Unveils 100G Coherent Components.)
According to Professor Jose, however, there is only so much you can do with "old-style" PICs. "We have a fundamental limit in doping photonic material like glass or silicon," he says. "If you take erbium-doped fiber amplifiers, for example, you are limited by how much erbium you can put in the silica. That's why we need very long optical fiber to get a sufficient amplification of the signal. So if you want a 1cm or shorter amplifier, instead of several meters, you need very large-scale doping levels, but you can't do that through conventional methods. You can, however, with our process."
ULPI, according to information provided by the University of Leeds, "uses high-powered, short-pulsed lasers to generate highly energetic plasma from a target material that is then implanted into another material." This new material can then be used to create much more efficient PICs, which, in turn, could have a profound effect on the economics of optical transport networks.
"Costs can be reduced because you can increase the number of amplifiers on a single chip, leading to very small and compact network devices that could be used, for example, in access networks," says Professor Jose. "You can also integrate splitters and amplifiers to reduce signal loss in the splitting process, which boosts performance. Scaling up the manufacturing process and integrating multiple photonic functionalities in smaller form factor with performance enhancement is the key to cost savings."
Professor Jose concedes this is still very early days, but he does expect commercial optical network devices -- based on next-generation PICS -- to start emerging as soon as 2017 or 2018.
There are already plans to integrate the new technology on to a "silicon platform", which relates to the collaboration work that Professor Jose's team is doing with the University of York and University of Sheffield on silicon optical interconnects. Plans are also afoot to do system level testing at the University of Cambridge, using devices manufactured in Leeds.
Aside from EPSRC funding, the ULPI manufacturing facility has also secured £1.5 million ($2.2 million) from 11 "industrial partners" and the other universities involved. The official acronym for the project is SeaMatics (Seamless Integration of Functional Materials for Advanced Photonics).
Professor Jose expects the new ULPI lab to be ready in 12 months' time, followed shortly afterwards by small-scale production of materials (but based on a process capable of being ramped up into large-scale production).
Although the main focus of SeaMatics is developing material for next-generation PICs, ULPI has other potential applications, says the University of Leeds, including "toughening mobile phone displays, building functional glasses for use in new types of biosensors, and creating novel anti-counterfeiting technology to protect products."
— Ken Wieland, contributing editor, special to Light Reading