Tài liệu Continuous Improvement in Fiber Optic Cable Assembly pptx

Continuous Improvement
in Fiber Optic Cable Assembly
Randy Reagan
Sean Grenon
Curtis Hill
WHITE PAPER
Network Service Providers continue to operate under increasing demands for
guaranteed service reliability. Providers that are actively deploying new
technology and networks are carefully scrutinizing all components that go into
a deployment for performance and reliability. Fiber optic cable assemblies are
no exception. To help ensure network integrity, service providers have turned
to standards organizations, suppliers and independent test agencies to
develop programs that can ensure fiber optic cable assembly performance and
reliability. Standards organizations have responded by developing
comprehensive requirements such as those found in GR-326-CORE, Issue 3
“Generic Requirements for Singlemode Optical Connectors and Jumper
Assemblies.” Suppliers have responded by developing improved fiber optic
connector technology resulting in cable assembly products that fully meet and
exceed these standards. Suppliers have also focused on process improvements
across a wide range of areas including product materials, facilities,
automation, testing, training and quality control. Independent test agencies
have responded by developing thorough test programs that validate connector
designs and cable assembly production processes and to ensure connectors
meet requirements for both inside plant and outside plant applications. The
results of continuous improvement efforts have been profound. Products
offered today are capable of consistent performance that exceeds standards
over a wide range of applications and environmental conditions. By
comparison, connectors manufactured recently offer incrementally better
performance than connectors manufactured just a few years ago. By selecting
products that have been certified to conform to standards, service providers
reap the benefits of an overall more reliable and economic solution.

Continuous Improvement in
Fiber Optic Cable Assemblies
Continuous Improvement in Fiber Optic Cable Assembly
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Today’s telecommunications environment continues to
be a landscape that is constantly changing. The
landscape is shaped by many factors including changes
in regulatory rulings, increased competition, new
technology, innovation and the status of the economy in
general. For instance the Telecommunications Act of
1996 and subsequent regulatory rulings encouraged
increased competition among service providers and
resulted in an increase of fiber deployment. During that
expansion period of the late 1990’s, the fiber optic
industry experienced a scarcity of fiber and components.
Suppliers scrambled to expand capacity but still could not
meet the demand of network expansion. In that
scenario, where demand exceeded supply, service
providers were often constrained to purchasing
components that were less than optimal.
Then, in 2001, the bubble burst for the telecomm-
unication industry. Since then we have witnessed a
dramatic reduction in demand. Today we are seeing a
paring of competitors to fewer service providers that are
leaner and stronger. The contraction in the economy and
telecommunications market has left the remaining
service providers in the driver’s seat with respect to
component procurement. Today service providers can
select components such as fiber cable assemblies based
on higher performance and lower cost than ever before.

While the telecommunication market has contracted,
service providers are still engaged in network construction
and expansion. New networks are needed to service
increased bandwidth requirements in the enterprise and
consumer markets. Service providers are deploying new
networks targeting new customers and new revenues.
Providers find that in today’s competitive environment,
reliability is more important than ever to their end
customers especially with the increased bandwidth placed
on individual fibers. Reliability is also paramount when
fiber cable assemblies are placed in outside plant
(uncontrolled) environments closer to customers.
Service providers that are actively deploying new
technology and networks including Fiber-to-the-Premises
(FTTP) are planning to use fiber connectors and cable
assemblies. Since there is no way to predict which end-
users will request new services, the optical connector
becomes a key point of flexibility. Providers building new
passive fiber plants want to build it right the first time
and then not have to replace components in the future.
Therefore they are scrutinizing all components for
performance and reliability with a view toward
performance over the long term. While fiber optic
connectors and cable assemblies may represent a small
fraction of the overall network cost, they continue to be
a vital link in connecting the entire network together.
Service providers have learned from experience that the
network is only as good as the weakest link and they do
not want the weakest link to be fiber cable assemblies.
Cable assembly suppliers are faced with seemingly

impossible demands; improve product performance,
quality, and reliability, and significantly reduce costs. The
approach taken by leading suppliers is to focus on overall
continuous quality improvement. This includes incremental
changes to product designs to optimize performance and
mechanical strength. Overall quality improvement also
involves changes to the assembly process including
improvements in the areas of facilities, training,
automation, calibration, testing and quality control.
Furthermore suppliers have taken initiative to provide
independent certification of the improved products and
processes. As a result of quality and process improvement
efforts, manufacturers can now provide a new level of
performance and reliability previously not available while
passing significant cost savings along to end users.
Key Performance Requirements
As advances in systems and components result in higher
throughput in communication networks, performance
expectations on fiber optic cable assemblies have
become more stringent. Several key performance
parameters for standard SC and LC fiber optic cable
assemblies are discussed in this section.
Insertion Loss - Many applications being deployed just a
few years ago with older style connectors (e.g. Biconic,
ST, FC, D4) had a typical insertion loss of 0.5dB. That
was the best performance available at the time.
Networks were often constrained by insertion loss of
passive connectors. Newer applications and network
deployments can draw from newer products with
improved performance. Insertion loss of less than 0.2dB

is commonplace in SC and LC jumpers deployed today.
Many suppliers are even providing ultra-low-loss cable
assemblies
1
having typical loss less of than 0.1dB. These
lower-loss connectors enable network deployments to be
more flexible than ever before.
Reflectance – Low reflectance will continue to be a critical
parameter in network deployment especially for high bit-
rate digital transmission and for broadband analog
applications. Therefore network planners today specify
connectors and cable assemblies with low return loss.
Today’s Ultra Physical Contact (UPC) polished connectors
can easily provide a return loss of less than -55dB. Many
suppliers are now able to surpass this mark and provide
typical return loss of less than –58dB with a UPC polish.
End Face Geometry - In order to achieve ultra-high
performance with common SC and LC connectors, the
polished end face geometry of the ceramic connector
ferrule is carefully defined to ensure that physical contact
is maintained between mated connectors. Critical
parameters including radius of curvature, fiber protrusion
and apex offset are measured on ceramic zirconia
ferrules and compared to standard tolerance that has
been adopted for UPC connectors.
Intermateability – Mechanical connectors such as the SC
connectors utilize a latching mechanism for joining
mated connector plugs. The latching mechanism is
defined in terms of the specific geometry of the
connector plug, adapter and associated latches. The

ferrule position relative to the latches is also carefully
defined dimensionally to ensure proper alignment and
contact force. The specific dimensions and tolerances for
optical connectors are contained in the FOCIS (Fiber
Optic Connector Intermateability Standard) require-ment
documents issued under TIE-EIA-604. The performance
of a connector can, in large part, be determined by
conformance to these dimensions.
Mechanical Strength – Fiber optic connector performance
is also characterized by the strength of the assembly in
normal handling and use. Several standard mechanical
tests have been developed to measure the cable assembly
ability to stand up to proof test loads. Tests are defined
for straight pull and side pull to represent normal
handling and the strength of the connection.
Miniature Cord Size – Ever space-conscious service
providers are deploying smaller diameter cable
assemblies to avoid congestion when installing new
equipment. Whereas cords of a few years ago were 3mm
in diameter, today’s cords are 1.6 mm to 2.0 mm in
diameter. Therefore, the customer wants a much smaller
package and is not willing to sacrifice any of the
performance objectives already mentioned here to get it.
Universal Applications – Traditional fiber optic cable
assemblies have most often been deployed into
controlled indoor environments. However more and
more intended applications include Fiber-to-the-Premises
require fibers to be used in uncontrolled outdoor
environments. Instead of having two different products,
one controlled and the other uncontrolled, users have

proposed to have one cable assembly that will serve
either environment. Therefore all of the performance
parameters discussed in this section are now expected to
perform over an environmental range of –40C to +85C
so that the same product can be used in either indoor or
outdoor applications.
Reliability Requirements
To evaluate connector performance and reliability, service
providers have turned to the industry standards
organizations and independent test agencies to develop
improved standards and test programs that can ensure
reliability. Telcordia GR-326-CORE, Issue 3, “Generic
Requirements for Singlemode Optical Connectors and
Jumper Assemblies”
2
, provides a comprehensive
standards document that is widely recognized as the most
rigorous baseline for fiber optic cable assembly
performance and reliability. In addition, intermateability
standards published in TIA Fiber Optic Connector
Intermateability (FOCIS)
3
documents cover various
connectors and dimensions critical to mechanical
intermateability. Also test methods published by the
EIA/TIA are widely regarded as the most complete and
rigorous standards for testing optical components. The
Telcordia and EIA/TIA standards contain the best collective
technical rationale and cover all of the performance
Continuous Improvement in Fiber Optic Cable Assembly

Page 4
criteria expected in network applications including
optical, environmental and mechanical requirements.
Testing a product to these standards provides a
comprehensive and accurate predictor of a product’s
ability to perform throughout its expected service life.
The GR-326-CORE, Issue 3 test sequence is designed to
thoroughly shake out any weakness in the connector
design. The test procedure involves measuring the optical
performance while subjecting the cable assembly to the
following sequence.
Baseline Per
for
mance
Insertion Loss
Reflectance
Endface Geometry
Envir
onmental Tests
Thermal Aging, 85°C, uncontrolled humidity, 7 days
Thermal Cycling, -40°C to 75°C, uncontrolled
humidity, 21 cycles in 7 days
Humidity Aging, 75°C, 95% RH, 7 days
Humidity/Condensation Cycling,-10°C to 65°C, 90%
RH, 14 cycles in 7 days
Post-Condensation Thermal Cycling
Mechanical T
ests Vibration
Flex, 100 cycles
Twist, 9 cycles, +360°, -720°, +360°

Proof
Transmission with applied load, straight pull
Transmission with applied load, side Pull
Transmission with applied load, 130°
Impact
Durability
Rematability
Connector Installation
End of T
est
Insertion Loss
Reflectance
Endface Geometry
Fiber optic cable assembly suppliers strive to satisfy these
standards. The goal is to provide customers with a reliable
product that can stand up to the conditions of these tests
over the life of the product. To gage performance suppliers
voluntarily submit products to independent 3rd party test
agencies. These agencies conduct the testing or witness
the testing on the product and attest to the validity of the
results. This may be in the form of a “Certificate of
Compliance” or a “Verification Report.” In addition, a
supplier may elect to qualify a product for either indoor
(controlled environment) or outdoor usage (uncontrolled
environment). As described in detail in Telcordia
Technologies Special Report SR-4226
4
, a Level 1
certification is for indoor use and a Level 2 certification is
for both indoor and outdoor use. In either case, a full test

report with all the raw data is submitted from the test
agency directly to the service provider showing how well
the product stands up to this rigorous test plan.
Product Improvements
The typical connectors specified for networks today,
including SC and LC
5
, are not the same designs of just a
few years ago. While these designs may look the same
and interconnect the same, the designs have evolved and
been continuously improved. Today’s SC and LC fiber optic
connectors and cable assembly designs have been
improved to the point where they now provide higher
performance and greater reliability than ever. Often,
changes to materials and components are required to
achieve enhanced performance and improvements in
cable assembly yields. Changes are implemented only after
thorough qualification testing to ensure that performance
and reliability can be maintained while achieving low
product costs. The following are examples of areas where
design improvements have been implemented:
Ferrule Material – The single mode cable assemblies
specified today utilize high quality and high precision
zirconia ferrules. However not all zirconia ferrules are
created equally. Therefore, a careful application of material
science has been used to understand the hardness and
crystalline composition of various ferrule designs. Through
this research, we can establish the optimal ferrule material
composition for achieving consistent end-face geometry
and consistency of other performance parameters under

conventional polishing techniques. The ferrule material is
not only optimized at ambient temperatures, but also over
a range of temperature and humidity conditions.
Continuous Improvement in Fiber Optic Cable Assembly
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Continuous Improvement in Fiber Optic Cable Assembly
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Fiber-Ferrule Geometry - Ceramic ferrules are specified
with closely controlled outside diameter, inside diameter
and concentricity. The ferrules are readily available with
precision concentricity and inside diameters that are
closely matched to the fiber. The end result in assembly is
a tight fit of fiber to ferrule and extremely centered fiber.
A centered fiber produces consistently excellent insertion
loss and with physical contact extremely low reflectance.
Plastic Materials - Stability of the plastic materials play an
extremely important role in the performance of the
connector and of the lifetime reliability. Materials used in
fiber optic cable assemblies must be carefully specified to
achieve performance and reliability over a range of
applications and environmental conditions. For instance
the plastic selection significantly can influence the
intermateability especially at extreme temperatures.
Therefore the plastics specified for the connector body
components are optimized to produce the desired
stability over a range of harsh environmental conditions.
Epoxy Adhesive – One of the key areas of fiber cable
assembly design is the epoxy used to lock the fiber into a
stable position inside the ferrule. Under high temperatures,
the fiber can creep and piston if the epoxy is not optimized

for stability over a range of environmental conditions
6
. In
addition, air bubbles intermixed with the epoxy can cause
havoc if allowed to enter the ferrule, therefore, care in
handling during mixing becomes crucial. The art of
selecting epoxy is not as easy as reading a specification
sheet. The designer needs to consider the way in which the
epoxy is mixed and applied and then how the fiber is cured.
An analysis of these variables and careful experimentation
and qualification can lead to a stabilized epoxy selection
over sustained environmental conditions. Often, the course
is to select premixed, degassed and frozen epoxy with the
desired formulation needed to meet the requirements.
Mechanical Crimp and Boot – In order to meet stringent
proof test requirements, the designer is faced with a
delicate balance of putting enough pressure on the fiber
cable while making sure that the glass is not stressed.
This design problem is especially challenging when trying
to meet the strength requirements using 1.60 mm cord
or 2.0 mm cord. However a careful analysis the design
can produce the optimal crimp geometry and pressure
even for the smallest miniature cord. This crimp is then
translated into connector barrel and crimp sleeve
materials and dimensions. In addition, the actual crimp
dimensions are optimized for automated crimp to
achieve a uniform pressure consistent from one
connector to the next. Finally, the boot is specified to
add side-pull strength that allows the connector to stand
up to the rugged mechanical test while maintaining

support for the fiber so that bending loss is not excessive.
Process Improvements
The entire assembly process for fiber optic cable assemblies
is engineered with the aim of producing connectors that
exceed performance in the Telcordia standards. Total quality
management is utilized to improve every aspect of the
process with a cumulative result that is often significant.
Some of the key process areas improved include:
Facilities - Particulates and contaminants having sub-
micron dimensions can adversely affect key fiber optic
cable assembly procedures such as polishing and testing.
To achieve the high performance now required in fiber
optic cable assemblies requires an upgrade of the
manufacturing facility to improve the environment. This
often involves using clean room facilities to provide a
controlled and monitored atmosphere for finishing and
testing cable assemblies.
Training - An updated training program is also instrumental
in achieving new levels of performance. A thorough
training program emphasizes proper techniques and
procedures for cable assembly. This includes both basic
training and specialized training techniques for high-
performance assembly including training in polishing,
testing or other specific procedures. It may also be
necessary to provide appropriate training on clean room
techniques in order to achieve maximum benefits of the
new environment.
Assembly - In the past, the cable assembly process has
typically been dominated by manual operations. Currently
there is a trend towards increased automation throughout

the process. Automation is especially effective where
designs are standardized; for instance, where a single
cable and connector type are specified. Automated tasks
Continuous Improvement in Fiber Optic Cable Assembly
Page 7
result in greater consistency and improve the throughput
of the overall assembly line. The trend toward automation
has helped to improve yields and performance in the
overall process. Manufacturers currently use automation in
the stripping process to help improve consistency and
eliminate occurrence of fiber breakage. Automated crimps
are utilized to overcome inconsistencies in hand operation
by applying uniform and complete pressure thus making
the mechanical joining of fiber cord to connector much
more reliable. Automated mixing and dispensing machines
bring consistency to epoxy application. Newer automated
curing ovens provide complete control of the cure
temperature thus providing a uniform temperature
distribution and duration of epoxy cure. New cure cycles
have been developed to provide optimized temperature
and cure duration to ensure a totally cured epoxy. Each
parameter of the polishing procedure is optimized to bring
tighter controls to the assembly process. The process also
incorporates automated data acquisition and recording so
that product performance can be monitored and improved
using Statistical Process Control (SPC).
Calibration - Equipment used in the manufacture of fiber
optic cable assemblies is subject to repeated use and
wear. For instance, stripping tools and polishing pucks
wear over time. Polishing paper can wear out throughout

the day. Test instruments need periodic adjustments and
recalibration. If any one piece of equipment is out of
calibration, it can result in reduced throughput and cost
inefficiencies. Therefore, it is imperative to institute a
program for calibration and periodic recalibration for each
piece of equipment used in the cable assembly process.
Assembly equipment in the manufacturing cell including
stripping machines, crimping machines, epoxy application
machines, polishing machines and test equipment are
periodically calibrated. A carefully designed program of
calibration at optimal intervals is required to maximize the
up-time of the assembly line and avoid rework. Samples
are reviewed several times during each shift to ensure the
overall process is in calibration and that product is
meeting end user requirements.
Testing – Fiber optic cable assemblies are tested to ensure
that products meet desired performance levels. Data is
collected and used to monitor the assembly process and
indicate where further improvements can be made. The
improved assembly process also institutes a geometry
check on fiber ends using highly automated
interferometers to ensure proper radius of curvature and
fiber protrusion on the connector ferrule end-face. The
geometry data is recorded in a database as part of the
permanent test record for the product. The data is also
correlated and used as feedback to continuously maintain
tight controls over the process.
Verification
As improvements are made to products and processes
verification testing is used to measure the degree of

improvement. As a first step towards verification, suppliers
will usually test products internally in their own test lab.
The test lab at a supplier location typically contains all of
the equipment and fixtures to test products to GR-326-
CORE, Issue 3. Vendor testing is often done incrementally
as changes are made so that the effect of each individual
change can be observed. Using this approach, the supplier
can gage the value of changes to increase performance or
reduce cost. The overarching objective is to achieve the
reliability standards set forth in the Telcordia requirements.
As product design changes are verified, samples are made
on the actual manufacturing line and again verified for
performance and reliability.
Once internal testing is satisfactorily completed, samples
are submitted to an independent test laboratory (e.g.
Telcordia Technologies, Underwriters Laboratories,
National Testing Services, ITS, etc). With this approach
product testing will be completed at the independent test
laboratory under the observance of the independent test
laboratory staff. The independent test agency is
responsible for carrying out the tests and providing a
completely objective and factual report. Testing a product
at an independent laboratory may result in a
“Certification” or “Verification” certificate indicating the
product conforms to all requirements. Since the service
provider will use the results of testing for comparative
analysis, they often will want to review the facilities and
procedures used at the test laboratory before testing to
make sure all laboratories provide consistent results. Some
service providers even provide a certification program for

independent test laboratories so that labs can be certified
for an entire family of products; e.g. optical components.
One alternative to testing at an independent laboratory
is to use witness testing. With witness testing, the
testing is typically done at the suppliers location and is
witnessed by representatives from the independent test
laboratory. This approach also results in a completely
objective and factual report. The advantage of this
approach to the supplier is that scheduling can be more
flexible since the supplier’s own technicians and facilities
are used to carry out testing. Service providers willing to
accept this approach may also elect to pre-certify the
suppliers optical lab. This pre-certification is usually done
as a cooperative effort between the service provider,
supplier and independent test agency. The overall
objective is to achieve consistency in the testing so that
results can be used in comparative analysis.
Verification does not stop with product performance and
reliability. Service providers also want assurance that the
manufacturing process used to make assemblies has the
appropriate quality controls to make them consistently.
To achieve this, the supplier uses the GR-326-CORE, Issue
3 Section 8 requirements and guidelines for product
manufacturing to guide the process control. To verify
that these process controls are in place, the supplier can
enlist the support of an independent test agency to
conduct a manufacturing audit. The test agency staff
will visit the supplier’s manufacturing location to review
appropriate process controls vs. the Section 8
requirements. In addition, the test agency will observe

product manufacture and select random samples for
further verification back at the independent test lab. This
process of manufacturing audit carries the verification
full circle and gives the service provider extensive data
with which to gage the performance, quality and
reliability of the manufactured product.
Product verification, both internal and independent
testing, are an integral part of the continuous
improvement process. The data gathered from
verification testing is used to identify strengths and
weaknesses in product performance and reliability as
well as improve the overall process for manufacture. The
data is extremely important in guiding further product
and process improvement efforts.
Continuous Improvement Results
A logical question is how much improvement can be
achieved? As a comparison, we reviewed independent
test results taken during two distinct points in time; one
sample tested in October 1998 and another sample
tested in July 2002. The test regiment conducted on
both occasions with score of passing results per test is
summarized on following page.
These results show successful completion of the test
program in both 1998 and 2002 resulting in Level 2
certification on both occasions. To achieve the Level 2
certification, 100% of the requirements were met. In
1998, the product satisfied 45% (18 out of 40) of the
objectives and in 2002 the product satisfied 90% (39 out
of 43) objectives. While objectives are not mandatory,
they do provide an important indicator of the products

overall ability to exceed industry requirements. This
increase from 1998 to 2002 shows a significant increase
in the ability of the product to exceed requirements and
meet the stretch goals set in the standards. The success in
optical performance throughout the 2002 certification
program was largely due to consistency in the connector
ferrule end-face geometry, stability of material used and
robustness of the mechanical design. In addition, the
manufacturing process developed consistently controls
the precision of every parameter at the ferrule end-face
resulting in performance and consistency that far exceeds
previous levels available in the industry. The insertion loss
averaging 0.12 dB at end of test is a significant
achievement. This accomplishment demonstrates that it is
possible to 100% satisfy all the very rigorous
requirements and tests set in Telcordia GR-326-CORE.
In 2002, samples of the same SC 2.0 mm product were
tested at both Telcordia Laboratories and Underwriters
Laboratories. The results of testing at the two independent
laboratories were correlated with both laboratories
achieving near identical results. The product at both
laboratories met 100% of the GR-326, Issue 3
requirements and over 90% of the objectives. This initiative
resulted in Level 2 certification status through Telcordia
Technologies Certification program and “Verification”
status at UL for indoor and outdoor product use.
Continuous Improvement in Fiber Optic Cable Assembly
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Continuous Improvement in Fiber Optic Cable Assembly
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Test Report Date October, 1998 July, 2002
Optical Performance: R O CR CO R O CR CO
New Product Loss 3/3 0/2 1/1 1/1 3/3 2/2 1/1 1/1
Thermal Aging 4/4 3/3 1/1 1/1 4/4 3/3 1/1 1/1
Thermal Cycling 4/4 1/3 1/1 1/1 4/4 2/3 1/1 1/1
Temp-Humidity Aging 4/4 1/3 1/1 1/1 4/4 3/3 1/1 1/1
Humidity Condensation 4/4 1/3 1/1 1/1 4/4 3/3 1/1 1/1
Post Thermal Cycling 4/4 1/3 1/1 1/1 4/4 2/3 1/1 1/1
Vibration 4/4 1/3 1/1 1/1 4/4 3/3 1/1 1/1
Rematability 4/4 2/2
Durability 4/4 0/3 1/1 1/1 4/4 2/3 1/1 0/1
Impact 4/4 1/3 0/1 0/1 4/4 3/3 1/1 0/1
Flex 4/4 3/3 0/1 0/1 4/4 3/3 1/1 0/1
Twist 4/4 3/3 0/1 0/1 4/4 3/3 0/1 0/1
Proof 4/4 1/3 0/1 0/1 4/4 3/3 1/1 0/1
Transmission with load 0° 2/2 1/1 0/1 0/1 2/2 1/1 1/1 0/1
Transmission with load 90° 2/2 1/1 0/1 0/1 2/2 1/1 1/1 0/1
Transmission with load 135° 2/2 0/1 1/1 1/1 1/2 0/1 1/1 0/1
Connector Installation 1/1 1/1
End of Test 3/3 0/2 0/1 0/1 3/3 2/2 1/1 0/1
Total Optical 56/56 18/40 11/18 9/16 61/61 39/43 15/16 7/16
Ferrule Endface Geometry:
Undercut/Protrusion 1/1 1/1
Radius of Curvature 1/1 1/1
Apex Offset 1/1 1/1
End of Test:
Ave. Insertion Loss 0.41 dB ± 0.05dB 0.12 dB ± 0.05dB
Ave. Reflectance -55 dB ± 2dB -56 dB ± 2dB
Overall Result Level 2 Certification (Issue 2) Level 2 Certification (Issue 3)
Test Report Date October, 1998 July, 2002

Requirements GR-326-CORE, Issue 2 GR-326-CORE, Issue 3
Certification Test Program SR-4226, Issue 1 SR-4226, Issue 2
Product SC SC
Cordage 3.0 mm 2.0 mm
Sample Size 16 16
Replacements
Replacements for No spares used
Mechanical tests
Test Laboratory
Telcordia Technologies Telcordia Technologies
(Formerly Bellcore)
As a final step in verification, a GR-326-CORE Section 8
manufacturing audit was conducted at the locations
where samples were produced. Underwriter’s Laboratories
conducted the 2002 Section 8 manufacturing audit at the
locations where samples were produced. Assembly lines
were audited in both the US and in Mexico. The results of
the audit were impressive. No major issues were identified
at either manufacturing location. In addition, product was
selected at random from the assembly lines at each
manufacturing location and sent back to UL laboratories
for testing. The performance testing results at UL
correlated to within ±0.02dB to those tested by the
supplier factories in the US and Mexico. Successful
completion of the manufacturing audit provides one more
assurance to the end user that highly reliable products can
be mass-produced and deployed.
Future Possibilities
Proponents of total quality methodology recognize that
continuous improvement is a never-ending process.

Therefore, the industry will pursue other areas for
improving features, performance and reliability for fiber
optic connectors and cable assemblies. Numerous
technology issues and trends will impact how connectors
are used and designed. Higher-power lasers are causing
the PC style of connectors to be scrutinized even more
carefully than ever. Current connectors should perform
adequately in high-power applications but cleanliness is
paramount. Therefore, we may see needs for connectors
that provide for ease of cleaning and maintenance. As
newer networks are deployed newer glass designs
including Reduced Water Peak fiber may be used to take
advantage of optical transmission across a broad
spectrum. Fiber optic cable assemblies may be color-
coded to identify fiber paths fully certified for wide-band
applications. Some of the newer fiber designs also
provide customized mode-field profiles that improve
bend performance in fibers. These new fibers allow the
construction of more robust cable assemblies able to
stand up to the rigors of field applications. More robust
fiber may be especially important for helping improve the
performance of small form factor connectors in high-
density environments or in harsh environments such as
outside plant applications. The small form factor
connector designs themselves may need to be improved
to provide overall better strength so that they can be
used in outside plant environments. Some applications
may require field-mounted connectors. Much is needed
to improve the performance and reliability of field-
mounted connectors so that they are comparable to

cable assembles manufactured in the factory. Finally,
much is needed in the area of design, standards and
testing for multi-fiber connectors so that they can be
compared as objectively as ceramic-ferrule Singlemode
PC connectors. All of these areas for innovation will
generate the need for continuous improvement.
Conclusion
Service providers concerned with deploying new
networks and new applications are scrutinizing the
performance and reliability of fiber optic cable assemblies
more than ever. In the current environment, service
providers can specify higher performance and reliability
while achieving significant cost reductions. The cause of
the service providers has been advanced by a combined
effort of standards organizations, suppliers and
independent test agencies. The results presented in this
paper represent best-in class performance and reliability
for fiber optic cable assembly. The products manufactured
today meet or exceed industry standard requirements in
every category. This claim has been substantiated through
independent testing at highly reputable laboratories
including Telcordia Technologies and Underwriters
Laboratories. Continuous improvement methodology will
continue to prove valuable as fiber optic connector and
cable assemblies are incrementally changed to serve users
in the years to come. A program of continuous testing to
ensure consistent performance and reliability must
accompany incremental continuous improvement.
Acknowledgement
The authors acknowledge the contribution of Osman

Gebizlioglu and John Peters at Telcordia Technologies
and Dave Wuestmann and Nicholas Fedrich at
Underwriters Laboratories. We also recognize the
contributions of colleagues at FONS including Ron
Cooper, Jim Henschel, Dan Rocheleau, Ed Santana, Matt
Brigham, Kathy Olson and Mike Noonan.
Continuous Improvement in Fiber Optic Cable Assembly
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Continuous Improvement in Fiber Optic Cable Assembly
Page 11
References
1
Ultra Low-Loss Cable Assembly Process Optimization,
Wood, K., NFOEC 2002 Proceedings.
2
GR-326-CORE, “Generic Requirements for Singlemode
Optical Connectors and Jumper Assemblies,” Issue 3,
September 1999.
3
TIA/EIA-604, Fiber Optic Connector Intermateability
Standards (FOCIS), November 1993.
4
SR-4226, Fiber Optic Connector and Jumper Assembly
Certification, Issue 2, January 2001.
5
LC Connector – The Emerging Connector Choice in
Current and Future Applications, C. Hill and A. Aponte,
NFOEC 2001 Proceedings.
6
Ceramic and Epoxy Reliability in Connectors Exposed to

Heat and Humidity, L. Reith, et.al., NFOEC 1998
Proceedings.
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