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: Say it with light: Using LEDs to move data faster

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.

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

FBI chief urges 'robust debate' on encryption

3 hours ago

FBI Director James Comey called Monday for public debate on the use of encrypted communications, saying Americans may not realize how radical groups and criminals are using the technology.

LG Display moves advanced touch tech up to notebooks

8 hours ago

LG Display has news for people who are into working with notebook PCs. They have announced lighter and slimmer LCD panels. Unleashing "Advanced In-cell Touch" (AIT) technology, LG Display said on Monday that ...

Italian surveillance company hacked, documents stolen

10 hours ago

An Italian surveillance firm known for selling malicious software used by police bodies and spy agencies has succumbed to a cyberattack, the firm's spokesman said Monday, confirming an embarrassing breach ...

Amazon pushes Prime service with day of deals

10 hours ago

Amazon is trying to lure more subscribers to its $99 Prime loyalty program by pushing a day of discounts it calls "Prime Day" during the sleepier summer shopping season.

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.