New automated process simplifies alignment and splicing of multicore optical fibers

Mar 12, 2013
The Fujikura FSM-100P+ fusion splicer is used for the automated alignment and splicing of MCF with PC control software developed by AFL. Credit: Image courtesy Fujikura Splicer Department

New multicore optical fibers have many times the signal-carrying capacity of traditional single-core fibers, but their use in telecommunications has been severely restricted because of the challenge in splicing them together— picture trying to match up and connect two separate boxes of spaghetti so that all of the noodles in each box are perfectly aligned. Now, a new splicing technique offers an automated way to do just that, with minimal losses in signal quality across the spliced sections. The method will be described at the Optical Fiber Communication Conference and Exposition/National Fiber Optic Engineers Conference (OFC/NFOEC) in Anaheim, Calif. March 17-21.

In the telecommunications industry, engineers maximize signal-carrying capacity using a process called multiplexing, which allows multiple signals or to be combined within a single fiber cable. One digital phone line, for example, uses 64 kilobits per second of bandwidth, but with a technique called time multiplexing, more than 1.5 million can take place at the same time, carried by one fiber . With wavelength multiplexing, that one fiber core can send up to 200 different simultaneously, increasing the capacity to 10 terabits per second, serving about 200 million phone lines. Those multiplexed fibers, in turn, can be bundled together into a so-called multicore fiber (MCF), consisting of up to 19 cores—and up to 19 times the signal-carrying capacity.

The challenge, however, is splicing those multicores together.

Researchers who work with MCFs in the lab usually have their own preferred manual processes for aligning and splicing fibers, explains Wenxin Zheng, manager of splice engineering at AFL in Duncan, S.C., who developed the new technique. "Although the manual way may be good for a skilled operator in a lab environment for research purposes, automation is the only path that can push MCF to factories and production lines."

In Zheng's process, which uses a Fujikura FSM-100P+ fusion splicer (see image), the fibers to be spliced are stripped and loaded into the splicer, then rotated and imaged with two video cameras so that their cores can be roughly aligned using a pattern-matching algorithm. Next, using a power-feedback method and image processing, a pair of corresponding cores in each fiber are finely aligned, as is the cladding around the cores. Finally, the cores are heat-spliced.

"To align the multiple cores simultaneously is a big challenge," Zheng says. "If two to be spliced have random core locations, there is no way to align the entire core." However, the component cores of MCFs can be aligned if they are created using the same design standard, and if the cores are distributed symmetrically in the MCF—such as in a seven-core MCF with one central core surrounded by six cores oriented like the spokes of a wagon wheel. In that case, Zheng notes, "we can fine-align one side-core in an MCF and its cladding at the same time. Based on the geometric specifications of the fiber, the rest of the cores will be automatically aligned."

Explore further: Denmark is world's most connected country

More information: Zheng's presentation, "Automated Alignment and Splicing for Multicore Fibers," will take place at 5 p.m. Monday, March 18 at the Anaheim Convention Center.

add to favorites email to friend print save as pdf

Related Stories

One petabit per second fiber transmission over 50 km

Sep 21, 2012

NTT and three partners- Nippon Telegraph and Telephone Corporation, Fujikura Ltd., Hokkaido University, and Technical University of Denmark—demonstrated ultra-large capacity transmission of 1 petabit (1000 ...

Recommended for you

BlackBerry courts iPhone users with cash

9 hours ago

Canadian smartphone maker BlackBerry is wooing Apple customers with a cash offer for trade-ins of iPhones for its new square-screened, keyboard-equipped Passport.

HP earnings show continued struggle

10 hours ago

Venerable tech giant Hewlett-Packard has been struggling for three years to turn its business around. Its latest earnings show it still has more work ahead.

UN moves to strengthen digital privacy (Update)

11 hours ago

The United Nations on Tuesday adopted a resolution on protecting digital privacy that for the first time urged governments to offer redress to citizens targeted by mass surveillance.

Spotify turns up volume as losses fall

11 hours ago

The world's biggest music streaming service, Spotify, announced Tuesday its revenue grew by 74 percent in 2013 while net losses shrank by one third, in a year of spectacular expansion.

Are electric cars greener? Depends on where you live

11 hours ago

Long thought a thing of the future, electric cars are becoming mainstream. Sales in the United States of plug-in, electric vehicles nearly doubled last year. Credible forecasts see the number rising within ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.