Fiber Optic Association, Inc.
Are There So Many Fiber Optic Connectors?
- The early
days of fiber optics were times of fast changing technologies. New
ideas popped up all the time. The earliest connecctor, the Deutsch
1000, had a bare fiber inside a large stainless body and used a plastic
conical alignment fixture with index -matching fluid. The AT&T
Biconic used a molded plastic ferrule, as did the AMP Optimate. The
Amphenol 905 used a machined stainless ferrule. Finally, in the
mid-80s, the Japanese developed the 2.5 mm ceramic ferrule which worked
much better. It was widely adopted and used since with little change,
but in numerous different body designs like the FC, ST, SC, FDDI, ESCON
- In the
late 90s, several manufacturers came our with "Small Form Factor
Connectors." They were designed to be, well, small. Most were simply
shrunken connectors with ceramic ferrules, except for the MT-RJ which
used a molded rectangular ferrule and the 3M Volition which went back
to the Deutsch bare fiber idea.
- A SFF
"standard" never happened in TIA TR 42.8 because it required a choice
between designs from several manufacturers and none of them wanted to
agree to a standard from a competitor. The TR 42.8 committee got a lot
of criticism because of that episode, mostly from users and equipment
manufacturers who wanted a single standard.
- In the
period following, none of those connectors has emerged as a defacto
standard. Not having a standard connector has been a major detriment to
fiber penetration to the desktop.
Do We Need A STANDARD Connector?
premises cabling, fiber is always competing with copper wiring that has
one connector and one cable (only in many different grades or
Categories.) Users considering fiber optics are expecting a "standard"
and are not happy with the proliferation of fiber optic connector
choices offered to them. Applications like Fiber To The Desk would be
so much easier to sell if there were only one choice, so let's get rid
of that objection. And standards lead to lower costs, the other big
issue for FTTD applications!
really talking about a connector for user patchcords, connecting wall
outlets and patch panels to networking equipment. What goes on behind
the patch panel is not an issue, so we can assume it's a patchcord
- We're not
concerned with the outside plant applications, as telcos are going to
do whatever they want anyway.
Kind Of Connector Are We Suggesting?
suggesting a standard small duplex connector created with some hard
a. It must be able to be manufactured cheaply using well-proven
technology and parts
b. It must be easily terminated using standard technology
c. It must be testable using industry standards. (Did you follow the
progress of 568's TSB-140 on fiber optic testing? It missed its mark
because no one could explain how to test certain connectors that are
not mateable with commonly used test equipment!)
d. It must be easily accommodated by transceivers, patch panels, and
e. The design specification must be "open source" - available to anyone
We Be More Specific?
- Do you
remember the FDDI and ESCON connectors? They were duplex connectors for
specific networks. We're thinking along the same lines but smaller,
e.g. using 1.25 mm ferrules in a plastic body the same size as a RJ-45
with a similar spring latch. Ideally, it would have ferrule spacing of
6.25 mm and depth specs the same as a duplex LC so it would allow
manufacturers to easily tool for it, especially for transceivers. It
would also allow using hybrid adapters to mate it with LCs, MUs and
LX-5s. So you could have a patch panel with FOA connectors on the user
side and LCs or MUs on terminated cables.
Not Just Use A Duplex LC? MT-RJ Or Optijack?
- A duplex
connector like the LC is a great connector, but it requires zipcord
when you make a patchcord and is bulky with the clip that holds two of
them together. It looks like two connectors clipped together, not a
duplex connector. What we hear is a smaller, neater connector using the
new smaller cable designs is more acceptable.
- The MT-RJ
is a much cleaner, more integrated, even aesthetic design, that can use
smaller 1.6 and 2 mm cables, but the ferrule has been the cause of many
issues, including creating great difficulty for test equipment
manufcaturers interfacing to it and users testing them properly.
- We like
the design of the OptiJack, but with the 2.5 mm ferrules at the chosen
spacing, it is only compatible to its own jack, not the SC, FC or ST
which use the same ferrule, which was an advantage of the FDDI and
FOA Is Not Designing A Connector!
understand that the FOA has no intention of designing a connector and
trying to force manufacturers to make it - we know that has no chance
of success! What we are doing is taking the input from our end user
contacts and feedback from some of our 13,000 CFOT certified
technicians and creating an idea for a connector that would be a simple
product to design or adapt hardware to, makes good sense and would be
acceptable to many manufacturers because of that and it is not a
Use The 1.25 mm ferrule?
1.25 mm ferrule is compatible with both singlemode and multimode
fibers, is more precisely made, has a shape that is easier to polish
and is compatible with any adhesive or other termination type. In
addition, the small ferrule size makes it easier to design a small
connector body as the ferrule takes up less space.
Using the 1.25 mm ferrule means it will be possible to have hubrid
mating adapters that can allow mating the FOA connector to the LC, MU
and LX-5, as well as any other connector designed around the same
In addition, feedback from the industry indicates the LC is overtaking
the SC in usage, meaning the smaller ferrules will be less expensive -
they even use less material too, if that's really a significant factor
Are We Doing Differently?
- The FOA
proposal is a different approach. Our board members are quite
experienced with fiber optic connectors and understand the issues of
technology and design quite well. We're especially aware of the
difficulty of terminating and testing some of the current connectors.
We feel we are competent to provide design guidelines for a new and
unique connector design that will not suffer the same fate as the
proprietary designs offered in the SFF because we are not a connector
manufacturer - we're not involved in products at all, in fact.
Exactly Is The FOA?
- The FOA is
a nonprofit educational organization chartered to promote fiber optics
through education, certification, standards, or any other appropriate
means. Since our founding in 1995, we have established a certification
program that has been used by over 125 schools to certify over 13,000
CFOTs (Certified Fiber Optic Technicians.) Organizations like NASA and
Cisco use our certification programs. We are promoting education by
creating introductory programs for teachers in secondary and technical
schools and posting them for free on our website. Over 5000 teachers
have downloaded our free introduction to fiber optics program for their
classes. We have just started a comprehensive "Train The Trainer"
online program to supplement our annual TTT seminars - also free to any
instructor interested in creating and teaching a fiber optic program.
- This year,
we decided to become involved more in standards programs. We had
already worked with NECA and ANSI to create a fiber optic installation
standard (NECA/FOA-301) and were monitoring and commenting on several
TR42.8 and FO-4 projects. I have begun attending standards meetings, at
first concentrating on TR 42.8 because work is just beginning on the
"C" revision of TIA-568. At the June meeting in Providence, I presented
a number of suggested changes, some quite substantial, for
consideration in the C revision of 568. It will probably take at least
2 years for this rev to work its way through the system.
- The FOA
has no members - individual or corporate. We're just a nonprofit
promoting fiber optics in ways we deem appropriate. We have not tried
to get support for the idea before going public, as we do not want to
be seen as representing any faction in this issue, we're just trying to
do what's best for the industry, especially in combating the
stranglehold that copper has on the desktop.
are we planning to do?
Introduce the concept to the industry.
- 2. Contact
component manufacturers, esp. transceiver manufacturers, to get their
reaction to our proposal for a standard connector. They seem to be very
interested in this project, because now they have to make so many
different physical interfaces to their products.
- 3. Get
input from networking standards committees. They have also expressed
disappointment at the SFF standardization failure.
- 4. Create
a design guideline. We do not plan to design a connector, just the
interface specifications, e.g. ferrule size, spacing and alignment, and
latching mechanism. We do not want to cross into patent or intellectual
property issues if at all possible. This guideline should be simple
enough to insure interoperability while allowing latitude for
manufacturers to design connectors that fit the interface spec and
offer unique features like ferrule shrouding. And it should be
inexpensive development since it uses available parts and technology.
- 5. Let the
industry and the market tell the manufacturers that this is important
to them and they want a standard product. Manufacturers will do what
the market wants. I have already heard from my contacts in several
connector manufacturers that they already know this is an important
issue and they believe we may have the proper way to establish a
- 6. Either
through one of the current standards committees or through one we
convene ourselves, invite all interested parties to join the design
process and provide their expertise to make this a workable concept.
From this stage, we create a FOCIS document (Fiber Optic Connector
- 7. Allow
manufacturers to bring the product to market.
- We at the
FOA know how hard this process will be, but we believe it's worth the
effort. When people and companies understand that we are altruistic -
really doing this because the industry needs it - and the FOA may well
be the only organization that has the knowledge, independence and
desire to make it happen, we expect to be taken seriously. And we have
The FOA Connector Proposal Be Compatible With Any Other Connectors?
proposed design is compatible with LC and MU connectors that use
the same ferrule. Mating adapters should be easy to produce that allow
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