November 8, 2005
NTT Develops Optical fiber Cord that can be easily bent, folded,
and tied, and enables easy connections
-- Ushers in an era in which anyone - not just experts - can install optical
fiber cables with a "DIY" approach --
Nippon Telegraph and Telephone Corp. (NTT; Head Office: Chiyoda-ku, Tokyo; President
and CEO: Norio Wada) has developed a revolutionary new optical fiber cord that
offers a degree of freedom in cable installation that was considered impossible
using conventional optical fiber. The new cable uses "Holey fiber [http://www.ntt.co.jp/news/news03e/0312/031217.html]"(*1),an
optical fiber with a new composition, for which NTT opened the way for new applications
ahead of any other manufacturer in the world. This new product was developed
through the combined efforts of NTT and its Group companies.
When conventional fiber is bent or folded forcefully, the optical signal inside
the fiber leaks, causing breaks in communication. The newly developed optical
fiber cord, however, enables smooth communications not only when bent or tied
into a knot, but even when it is folded at a right angle. Because it can be used
far more easily than any existing optical fiber cord, as long as there is an
optical outlet (*2) in the user's home, anybody can easily install an optical
fiber cable in their room themselves, even if they have no specialized skills
or knowledge (Fig. 1).
Based on its current management goal of "Providing optical services and
next-generation network services to 30 million customers by 2010," the entire
NTT group will work to promote the implementation of optical fiber networks in
preparation for the expansion and proliferation of optical fiber services. This
revolutionary optical fiber cord improves efficiency in the process of laying
optical fiber cables, which has been considered a problem in the past, and supports
the opening up of large-volume optical fiber communications in the future.
Background to Development
With the rapid proliferation of optical fiber services, we are entering an era
in which optical fibers are becoming a common fixture in regular households.
Up to now, installing these cables in the home required specialized tools, and
great care had to be taken because folding or otherwise excessively bending the
fiber could cause breaks in communication; as a result, the installation task
required a high level of specialized skills. Particularly in the case of in-home
installations, the workmen always made sure to leave enough optical fiber cable
that the customers could set up the computer terminals in keeping with their
own lifestyles, but large bundles of cable tend to get in the way, and also make
the room look cluttered.
The most promising way of installing optical fiber cable in even more homes in
the future in an even shorter period of time, and ensuring maximum customer satisfaction,
is to enable these cables to be installed neatly and easily, as in the case of
existing metal cables.
The new optical fiber cable is comprised of highly flexible "Holey fiber," a
protective cord covering, and a newly developed connector. The unique features
of each of these three components, which are outlined below, combine to achieve
outstanding optical and mechanical characteristics that could not be attained
with conventional optical fiber cable.
(1) "Hole-assisted" Holey optical fiber
"Holey fiber," the central component in this product, uses "hole-assisted" fiber
that contains a highly refractive glass core surrounded by glass with many small
holes to achieve the optical and mechanical characteristics demanded for in-home
optical fibers (Fig. 2). The refractive index of air is considerably less than
that of silica glass, so this fiber acts as a reflective material to prevent
any light from escaping, thus increasing its ability to trap the light inside.
By trapping the light in this way, the light can pass through the fiber no matter
how much the cable is bent, folded, or tied.
(2) Extremely flexible optical cord with high resistance to lateral pressure
The construction of this optical fiber cord, which is 4mm in diameter, reduces
the burden on the optical fiber inside even if the cable is bent or stepped on.
It also utilizes a flexible material that bends smoothly to ensure maximum ease
of handling. In this way, the cable offers enough flexibility to allow smooth
bending for easy installation around the user's terminal, as well as resistance
to lateral pressure so that the optical fiber inside is not affected even if
the user accidentally runs over the cable with the wheels of a chair. Another
major advantage of this cable is that it remains smooth and flexible even when
extra cable is tied up or bundled, rather than retaining the shape of the knot.
(3) Dust-resistant connectors with easy-cleaning function
The connectors on this cable are compatible with standard SC connectors (*3),
and have a dust-resistant function that prevents dust from adhering to the connector
surfaces when the user who has no specialized skills or knowledge connects or
disconnects the cable. They are also equipped with a simple cleaning function
that allows the user to easily remove any dust that might still appear on the
Optical fiber cord
- Hole-assisted optical fiber; single core cord
- Cord diameter: 4.0mm
- Cord length: 1.5m, 3m, 5m
- Compatible with standard SC optical connectors
- Simple cleaning function and dust-resistant function on connector surfaces
This revolutionary optical fiber cord is the first of its kind anywhere in the
world. It incorporates the results of advanced research and development at NTT
Laboratories to enable safe and easy applications by users even if they have
no specialized skills or knowledge. Development of the cord will be completed
before the end of 2005, and the product will be available to customers within
the current fiscal year (ending March 31, 2006). This product is expected to
add great momentum to the shift to "Do-It-Yourself" installations of
optical fiber cables, which is expected to take place in the not-too-distant
*1 Holey Fiber
The common name for optical fiber made from glass containing many tiny air holes.
Among the more common types of Holey fibers are: Hole-assisted fiber (a highly
refractive core surrounded by glass with many small holes), photonic crystal
fiber (a silica glass core and glass with many holes), and photonic band gap
fiber (a hollow core and glass with many small holes).
*2 Optical outlets
Similar to a modular jack for a telephone cable. These outlets, which contain
an optical connector interface, come in two types: an "embedded type," in
which the outlet is embedded in a switch box, and an "exposed type," in
which the outlet itself is installed in the wall.
*3 SC connector
An optical connector created during the development of optical components in
the basic research stages at NTT Laboratories. With the development of subscriber-type
optical access systems, these connectors came to be recognized as being extremely
economical, and since then they have in effect become the global standard for
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Planning Division; Public Relations:
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