Fiber optic cable testing involves measuring several key parameters:
1) Optical power levels using a power meter and light source to check for attenuation or loss in fibers and connectors.
2) Back reflection or return loss using an OTDR or OCWR to measure reflections at splices or connectors.
3) Fault location using an OTDR, VFL, or microscope to identify breaks, damage or contamination.
Proper testing ensures fiber optic networks are functioning within specifications.
This is a fiber optic cable testing device that injects a series of optical pulses into the fiber under test and extracts, from the same end of the fiber, light that is scattered The strength of the return pulses is measured and integrated as a function of time, and plotted as a function of fiber length. which is called TRACE
OTDR(OPTICAL TIME DOMAIN REFLECTOMETER)Shail Mishra
OTDR, OPTICAL TIME DOMAIN REFLECTOMETER, How to calculate link budget, Basic of Wavelength, FTTH Network, Working Principle of OTDR, OTDR BASIC PARAMETER.
An Optical Time Domain Reflectometer (OTDR) is an important instrument used by organizations to certify the performance of new fiber optics links and detect problems with existing fiber links.
Aq7275 Hướng dẫn sử dụng máy đo sợi cáp quang Yokogawa otdrMr Calvin Pham
Máy đo sợi cáp quang OTDR model AQ7275 là dòng máy đo chuẩn và chính xác trên thị trường. Tuổi thọ Pin của máy đo cao, dễ dàng thay thế và sữa chữa
tham khảo chi tiết tại : www.phukienquang.net
This is a fiber optic cable testing device that injects a series of optical pulses into the fiber under test and extracts, from the same end of the fiber, light that is scattered The strength of the return pulses is measured and integrated as a function of time, and plotted as a function of fiber length. which is called TRACE
OTDR(OPTICAL TIME DOMAIN REFLECTOMETER)Shail Mishra
OTDR, OPTICAL TIME DOMAIN REFLECTOMETER, How to calculate link budget, Basic of Wavelength, FTTH Network, Working Principle of OTDR, OTDR BASIC PARAMETER.
An Optical Time Domain Reflectometer (OTDR) is an important instrument used by organizations to certify the performance of new fiber optics links and detect problems with existing fiber links.
Aq7275 Hướng dẫn sử dụng máy đo sợi cáp quang Yokogawa otdrMr Calvin Pham
Máy đo sợi cáp quang OTDR model AQ7275 là dòng máy đo chuẩn và chính xác trên thị trường. Tuổi thọ Pin của máy đo cao, dễ dàng thay thế và sữa chữa
tham khảo chi tiết tại : www.phukienquang.net
Benefits of enhanced event analysis in datacenter otdr testingFangXuIEEE
Automatic detection and analysis algorithm of events in OTDR traces is very a challenging signal processing and analysis problem. It has too many tradeoffs to overcome: sensitivity vs. reliability, complexity vs. execution time. Traditional signal processing methods quickly reach performance limits. This is a place to demonstrate peoples creativity of finding exotic algorithm and method.
Nov 12 Webcast: Eliminate Pitfalls of DDR Memory Testing
Join Teledyne LeCroy's, Mike Hertz, for this free webinar on using an oscilloscope for validation and debug of DDR2/3/4 physical layer measurements.
Topics covered will include: probing, connectivity, recommended device patterns, de-embedding, examples of good and bad waveforms, and debugging steps and techniques.
Mike Hertz has been a Field Applications Engineer with Teledyne LeCroy in Michigan for 14 years.
Join Teledyne LeCroy for a discussion of what S-parameters are and why we should care about them. As serial data rates move into the multi-gigabit domain, S-parameters play an important role in understanding system performance. We will uncover the four main patterns found in s-parameters and learn what they can tell us about our interconnects.
Angstrom Advanced is the leading supplier for ellipsometers. We offer full range of ellipsometers for thin film thickness measurement and optical characterization for refractive index and extinction coefficient (n & k). The Angstrom Advanced ellipsometer family includes discrete wavelength ellipsometers (single wavelength ellipsometers and multi-wavelength ellipsometers), deep UV, UV, VIS, NIR and IR spectroscopic ellipsometers. Our ellipsometers have been delivered to many renowned universities, research institutes and companies worldwide. Angstrom Advanced's goal is to supply the most accurate and repeatable ellipsometers with the highest standard of customer satisfaction. Many upgrade accessories are available for different applications.
Formats for coherent optical communications -OPTICAL COMMUNICATIONSNITHIN KALLE PALLY
Coherent optical communication
Coherent optical communication systems applying modulation formats with a dimensionality of four or higher are investigated and compared to systems using conventional formats.
Higher dimensionality can be achieved by applying modulation over more than one polarization, time-slot, wavelength, mode or core. Both uncoded systems and systems applying forward-error correction (FEC) coding are studied in terms of spectral efficiency and sensitivity.
It is shown that increasing the dimensionality for a constant spectral efficiency improves the sensitivity substantially if no coding is applied, whereas the corresponding gains generally are much smaller in FEC-coded systems.
Essential principles of jitter part 2 the components of jitterteledynelecroy
-The power of statistical analysis
-The five fundamental types of jitter: ISI, DCD, Periodic, Random, Other
-Their statistical “signature”
-The jitter “tree”
-Synthesizing examples based on their root cause
Polymer Waveguide Based Optical Interconnects for High-Speed On-Board Communi...Jian Chen
Multimode polymer waveguides constitute an attractive technology for use in board-level optical interconnects:
- Theoretical model of bandwidth estimation of MM WGs developed;
- Frequency and time domain measurements on 1 m long spiral waveguides conducted;
- Bandwidth performance of multimode WGs can be enhanced using refractive index engineering, launch conditions, waveguide layout, etc.;
- Record 40 Gb/s NRZ and 56 Gb/s PAM-4 over 1 m long waveguide demonstrated.
PAM4 Analysis and Measurement Considerations WebinarHilary Lustig
This webinar explores the acquisition and analysis of PAM4 waveforms. We will show PAM4 Test Configurations, Compliance Measurements and Debug Techniques.
Benefits of enhanced event analysis in datacenter otdr testingFangXuIEEE
Automatic detection and analysis algorithm of events in OTDR traces is very a challenging signal processing and analysis problem. It has too many tradeoffs to overcome: sensitivity vs. reliability, complexity vs. execution time. Traditional signal processing methods quickly reach performance limits. This is a place to demonstrate peoples creativity of finding exotic algorithm and method.
Nov 12 Webcast: Eliminate Pitfalls of DDR Memory Testing
Join Teledyne LeCroy's, Mike Hertz, for this free webinar on using an oscilloscope for validation and debug of DDR2/3/4 physical layer measurements.
Topics covered will include: probing, connectivity, recommended device patterns, de-embedding, examples of good and bad waveforms, and debugging steps and techniques.
Mike Hertz has been a Field Applications Engineer with Teledyne LeCroy in Michigan for 14 years.
Join Teledyne LeCroy for a discussion of what S-parameters are and why we should care about them. As serial data rates move into the multi-gigabit domain, S-parameters play an important role in understanding system performance. We will uncover the four main patterns found in s-parameters and learn what they can tell us about our interconnects.
Angstrom Advanced is the leading supplier for ellipsometers. We offer full range of ellipsometers for thin film thickness measurement and optical characterization for refractive index and extinction coefficient (n & k). The Angstrom Advanced ellipsometer family includes discrete wavelength ellipsometers (single wavelength ellipsometers and multi-wavelength ellipsometers), deep UV, UV, VIS, NIR and IR spectroscopic ellipsometers. Our ellipsometers have been delivered to many renowned universities, research institutes and companies worldwide. Angstrom Advanced's goal is to supply the most accurate and repeatable ellipsometers with the highest standard of customer satisfaction. Many upgrade accessories are available for different applications.
Formats for coherent optical communications -OPTICAL COMMUNICATIONSNITHIN KALLE PALLY
Coherent optical communication
Coherent optical communication systems applying modulation formats with a dimensionality of four or higher are investigated and compared to systems using conventional formats.
Higher dimensionality can be achieved by applying modulation over more than one polarization, time-slot, wavelength, mode or core. Both uncoded systems and systems applying forward-error correction (FEC) coding are studied in terms of spectral efficiency and sensitivity.
It is shown that increasing the dimensionality for a constant spectral efficiency improves the sensitivity substantially if no coding is applied, whereas the corresponding gains generally are much smaller in FEC-coded systems.
Essential principles of jitter part 2 the components of jitterteledynelecroy
-The power of statistical analysis
-The five fundamental types of jitter: ISI, DCD, Periodic, Random, Other
-Their statistical “signature”
-The jitter “tree”
-Synthesizing examples based on their root cause
Polymer Waveguide Based Optical Interconnects for High-Speed On-Board Communi...Jian Chen
Multimode polymer waveguides constitute an attractive technology for use in board-level optical interconnects:
- Theoretical model of bandwidth estimation of MM WGs developed;
- Frequency and time domain measurements on 1 m long spiral waveguides conducted;
- Bandwidth performance of multimode WGs can be enhanced using refractive index engineering, launch conditions, waveguide layout, etc.;
- Record 40 Gb/s NRZ and 56 Gb/s PAM-4 over 1 m long waveguide demonstrated.
PAM4 Analysis and Measurement Considerations WebinarHilary Lustig
This webinar explores the acquisition and analysis of PAM4 waveforms. We will show PAM4 Test Configurations, Compliance Measurements and Debug Techniques.
These slides use concepts from my (Jeff Funk) course entitled analyzing hi-tech opportunities to show how nanotechnology for drug deliver is becoming economically feasible.
Testing a fiber optic transceiver is a complicated job, but it is an indispensable step to ensure its performance. Basic eye-mask test is an effective way to test a transmitter and is still widely used today.
"OTDR" redirects here. Not to be confused with On-Train Data Recorder.
An OTDR
An optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to characterize an optical fiber. It is the optical equivalent of an electronic time domain reflectometer which measures the impedance of the cable or transmission line under test. An OTDR injects a series of optical pulses into the fiber under test and extracts, from the same end of the fiber, light that is scattered (Rayleigh backscatter) or reflected back from points along the fiber. The scattered or reflected light that is gathered back is used to characterize the optical fiber. The strength of the return pulses is measured and integrated as a function of time, and plotted as a function of length of the fiber.
Reliability and quality of OTDR equipment
The reliability and quality of an OTDR is based on its accuracy, measurement range, ability to resolve and measure closely spaced events, measurement speed, and ability to perform satisfactorily under various environmental extremes and after various types of physical abuse. The instrument is also judged on the basis of its cost, features provided, size, weight, and ease of use.
Some of the terms often used in specifying the quality of an OTDR are as follows:
Accuracy: Defined as the correctness of the measurement i.e., the difference between the measured value and the true value of the event being measured.
Measurement range: Defined as the maximum attenuation that can be placed between the instrument and the event being measured, for which the instrument will still be able to measure the event within acceptable accuracy limits.
Instrument resolution: Is a measure of how close two events can be spaced and still be recognized as two separate events. The duration of the measurement pulse and the data sampling interval create a resolution limitation for OTDRs. The shorter the pulse duration and the shorter the data sampling interval, the better the instrument resolution, but the shorter the measurement range. Resolution is also often limited when powerful reflections return to the OTDR and temporarily overload the detector. When this occurs, some time is required before the instrument can resolve a second fiber event. Some OTDR manufacturers use a “masking” procedure to improve resolution. The procedure shields or “masks” the detector from high-power fiber reflections, preventing detector overload and eliminating the need for detector recovery.
Industry requirements for the reliability and quality of OTDRs are specified in the Generic Requirements for Optical Time Domain Reflectometer (OTDR) Type Equipment.[1]
Types of OTDR-like test equipment
The common types of OTDR-like test equipment are:
Full-feature OTDR:
Full-feature OTDRs are traditional, optical time domain reflectometers. They are feature-rich and usually larger, heavier, and less portable than either the hand-held OTDR or the fiber break locator. Despite being characterized
Tata Group Dials Taiwan for Its Chipmaking Ambition in Gujarat’s DholeraAvirahi City Dholera
The Tata Group, a titan of Indian industry, is making waves with its advanced talks with Taiwanese chipmakers Powerchip Semiconductor Manufacturing Corporation (PSMC) and UMC Group. The goal? Establishing a cutting-edge semiconductor fabrication unit (fab) in Dholera, Gujarat. This isn’t just any project; it’s a potential game changer for India’s chipmaking aspirations and a boon for investors seeking promising residential projects in dholera sir.
Visit : https://www.avirahi.com/blog/tata-group-dials-taiwan-for-its-chipmaking-ambition-in-gujarats-dholera/
Cracking the Workplace Discipline Code Main.pptxWorkforce Group
Cultivating and maintaining discipline within teams is a critical differentiator for successful organisations.
Forward-thinking leaders and business managers understand the impact that discipline has on organisational success. A disciplined workforce operates with clarity, focus, and a shared understanding of expectations, ultimately driving better results, optimising productivity, and facilitating seamless collaboration.
Although discipline is not a one-size-fits-all approach, it can help create a work environment that encourages personal growth and accountability rather than solely relying on punitive measures.
In this deck, you will learn the significance of workplace discipline for organisational success. You’ll also learn
• Four (4) workplace discipline methods you should consider
• The best and most practical approach to implementing workplace discipline.
• Three (3) key tips to maintain a disciplined workplace.
Kseniya Leshchenko: Shared development support service model as the way to ma...Lviv Startup Club
Kseniya Leshchenko: Shared development support service model as the way to make small projects with small budgets profitable for the company (UA)
Kyiv PMDay 2024 Summer
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The world of search engine optimization (SEO) is buzzing with discussions after Google confirmed that around 2,500 leaked internal documents related to its Search feature are indeed authentic. The revelation has sparked significant concerns within the SEO community. The leaked documents were initially reported by SEO experts Rand Fishkin and Mike King, igniting widespread analysis and discourse. For More Info:- https://news.arihantwebtech.com/search-disrupted-googles-leaked-documents-rock-the-seo-world/
[Note: This is a partial preview. To download this presentation, visit:
https://www.oeconsulting.com.sg/training-presentations]
Sustainability has become an increasingly critical topic as the world recognizes the need to protect our planet and its resources for future generations. Sustainability means meeting our current needs without compromising the ability of future generations to meet theirs. It involves long-term planning and consideration of the consequences of our actions. The goal is to create strategies that ensure the long-term viability of People, Planet, and Profit.
Leading companies such as Nike, Toyota, and Siemens are prioritizing sustainable innovation in their business models, setting an example for others to follow. In this Sustainability training presentation, you will learn key concepts, principles, and practices of sustainability applicable across industries. This training aims to create awareness and educate employees, senior executives, consultants, and other key stakeholders, including investors, policymakers, and supply chain partners, on the importance and implementation of sustainability.
LEARNING OBJECTIVES
1. Develop a comprehensive understanding of the fundamental principles and concepts that form the foundation of sustainability within corporate environments.
2. Explore the sustainability implementation model, focusing on effective measures and reporting strategies to track and communicate sustainability efforts.
3. Identify and define best practices and critical success factors essential for achieving sustainability goals within organizations.
CONTENTS
1. Introduction and Key Concepts of Sustainability
2. Principles and Practices of Sustainability
3. Measures and Reporting in Sustainability
4. Sustainability Implementation & Best Practices
To download the complete presentation, visit: https://www.oeconsulting.com.sg/training-presentations
Memorandum Of Association Constitution of Company.pptseri bangash
www.seribangash.com
A Memorandum of Association (MOA) is a legal document that outlines the fundamental principles and objectives upon which a company operates. It serves as the company's charter or constitution and defines the scope of its activities. Here's a detailed note on the MOA:
Contents of Memorandum of Association:
Name Clause: This clause states the name of the company, which should end with words like "Limited" or "Ltd." for a public limited company and "Private Limited" or "Pvt. Ltd." for a private limited company.
https://seribangash.com/article-of-association-is-legal-doc-of-company/
Registered Office Clause: It specifies the location where the company's registered office is situated. This office is where all official communications and notices are sent.
Objective Clause: This clause delineates the main objectives for which the company is formed. It's important to define these objectives clearly, as the company cannot undertake activities beyond those mentioned in this clause.
www.seribangash.com
Liability Clause: It outlines the extent of liability of the company's members. In the case of companies limited by shares, the liability of members is limited to the amount unpaid on their shares. For companies limited by guarantee, members' liability is limited to the amount they undertake to contribute if the company is wound up.
https://seribangash.com/promotors-is-person-conceived-formation-company/
Capital Clause: This clause specifies the authorized capital of the company, i.e., the maximum amount of share capital the company is authorized to issue. It also mentions the division of this capital into shares and their respective nominal value.
Association Clause: It simply states that the subscribers wish to form a company and agree to become members of it, in accordance with the terms of the MOA.
Importance of Memorandum of Association:
Legal Requirement: The MOA is a legal requirement for the formation of a company. It must be filed with the Registrar of Companies during the incorporation process.
Constitutional Document: It serves as the company's constitutional document, defining its scope, powers, and limitations.
Protection of Members: It protects the interests of the company's members by clearly defining the objectives and limiting their liability.
External Communication: It provides clarity to external parties, such as investors, creditors, and regulatory authorities, regarding the company's objectives and powers.
https://seribangash.com/difference-public-and-private-company-law/
Binding Authority: The company and its members are bound by the provisions of the MOA. Any action taken beyond its scope may be considered ultra vires (beyond the powers) of the company and therefore void.
Amendment of MOA:
While the MOA lays down the company's fundamental principles, it is not entirely immutable. It can be amended, but only under specific circumstances and in compliance with legal procedures. Amendments typically require shareholder
VAT Registration Outlined In UAE: Benefits and Requirementsuae taxgpt
Vat Registration is a legal obligation for businesses meeting the threshold requirement, helping companies avoid fines and ramifications. Contact now!
https://viralsocialtrends.com/vat-registration-outlined-in-uae/
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Implicitly or explicitly all competing businesses employ a strategy to select a mix
of marketing resources. Formulating such competitive strategies fundamentally
involves recognizing relationships between elements of the marketing mix (e.g.,
price and product quality), as well as assessing competitive and market conditions
(i.e., industry structure in the language of economics).
Discover the innovative and creative projects that highlight my journey throu...dylandmeas
Discover the innovative and creative projects that highlight my journey through Full Sail University. Below, you’ll find a collection of my work showcasing my skills and expertise in digital marketing, event planning, and media production.
RMD24 | Debunking the non-endemic revenue myth Marvin Vacquier Droop | First ...BBPMedia1
Marvin neemt je in deze presentatie mee in de voordelen van non-endemic advertising op retail media netwerken. Hij brengt ook de uitdagingen in beeld die de markt op dit moment heeft op het gebied van retail media voor niet-leveranciers.
Retail media wordt gezien als het nieuwe advertising-medium en ook mediabureaus richten massaal retail media-afdelingen op. Merken die niet in de betreffende winkel liggen staan ook nog niet in de rij om op de retail media netwerken te adverteren. Marvin belicht de uitdagingen die er zijn om echt aansluiting te vinden op die markt van non-endemic advertising.
Unveiling the Secrets How Does Generative AI Work.pdfSam H
At its core, generative artificial intelligence relies on the concept of generative models, which serve as engines that churn out entirely new data resembling their training data. It is like a sculptor who has studied so many forms found in nature and then uses this knowledge to create sculptures from his imagination that have never been seen before anywhere else. If taken to cyberspace, gans work almost the same way.
LA HUG - Video Testimonials with Chynna Morgan - June 2024Lital Barkan
Have you ever heard that user-generated content or video testimonials can take your brand to the next level? We will explore how you can effectively use video testimonials to leverage and boost your sales, content strategy, and increase your CRM data.🤯
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LA HUG - Video Testimonials with Chynna Morgan - June 2024
Ch17
1. Fiber Optic Cable TestingFiber Optic Cable Testing
Ch 17Ch 17
Fiber Optics Technician’sFiber Optics Technician’s
Manual, 3Manual, 3rdrd
. Ed. Ed
Jim HayesJim Hayes
Revised 11-24-08
2. Testing RequirementsTesting Requirements
ParameterParameter ExampleExample InstrumentInstrument
Optical powerOptical power Source output,Source output,
receiver signalreceiver signal
levellevel
Power meterPower meter
Attenuation or lossAttenuation or loss Fibers, cables,Fibers, cables,
connectorsconnectors
Power meter andPower meter and
source, or Optical Losssource, or Optical Loss
Test Set (OLTS)Test Set (OLTS)
Back reflection orBack reflection or
Optical Return LossOptical Return Loss
(ORL)(ORL)
OTDR or OCWROTDR or OCWR
(Optical Continuous(Optical Continuous
Wave Reflectometer)Wave Reflectometer)
Source wavelengthSource wavelength Spectrum analyzerSpectrum analyzer
BackscatterBackscatter Loss, length,Loss, length,
fault locationfault location
OTDROTDR
Fault locationFault location OTDR, VFLOTDR, VFL
Bandwidth/dispersionBandwidth/dispersion Bandwidth testerBandwidth tester
3. Power MetersPower Meters
The power meter by itself can beThe power meter by itself can be
use to measure source poweruse to measure source power
With a source, it can measure theWith a source, it can measure the
loss of a cable plant, calledloss of a cable plant, called
insertion lossinsertion loss
Most power measurements are inMost power measurements are in
the range +10 dBm to -40 dBmthe range +10 dBm to -40 dBm
• Analog CATV (cable TV) or DWDMAnalog CATV (cable TV) or DWDM
(Dense Wavelength Division(Dense Wavelength Division
Multiplexing) systems can haveMultiplexing) systems can have
power up to +30 dBm (1 watt)power up to +30 dBm (1 watt)
Image from
lanshack.com
4. WavelengthsWavelengths
Power meters are calibrated at threePower meters are calibrated at three
standard wavelengthsstandard wavelengths
• 850 nm, 1300 nm, 1550 nm850 nm, 1300 nm, 1550 nm
Typical measurement uncertainty isTypical measurement uncertainty is
5% (0.2 dB)5% (0.2 dB)
5. SourcesSources
Sources are either LED or laserSources are either LED or laser
• 665 nm for plastic optical fiber665 nm for plastic optical fiber
• 850 nm or 1300 nm for multimode850 nm or 1300 nm for multimode
• 1310 nm or 1550 nm for singlemode1310 nm or 1550 nm for singlemode
Test your system with a sourceTest your system with a source
similar to the one that will besimilar to the one that will be
actually used to send dataactually used to send data
Image from
lanshack.com
6. Optical Loss Test SetOptical Loss Test Set
Power meter and sourcePower meter and source
in a single unitin a single unit
• Normally used in pairsNormally used in pairs
• Automated, more complexAutomated, more complex
and expensive than theand expensive than the
combination of a sourcecombination of a source
and a power meterand a power meter
Rare in field testingRare in field testing
• Image from aflfiber.comImage from aflfiber.com
8. OTDR UsesOTDR Uses
Measure lossMeasure loss
Locate breaks, splices, andLocate breaks, splices, and
connectorsconnectors
Produces graphic display of fiberProduces graphic display of fiber
statusstatus
• Can be stored for documentation andCan be stored for documentation and
later referencelater reference
Cable can be measured from one endCable can be measured from one end
9. BackscatterBackscatter
A small amount of light is scattered backA small amount of light is scattered back
to the source from the fiber itselfto the source from the fiber itself
Splices or connector pairs cause a largerSplices or connector pairs cause a larger
reflection of light back to the sourcereflection of light back to the source
• Figure from techoptics.com (link Ch 17a)Figure from techoptics.com (link Ch 17a)
11. OTDR AccuracyOTDR Accuracy
OTDR can give false loss valuesOTDR can give false loss values
when coupling different fiberswhen coupling different fibers
togethertogether
• Splices can even show more light on theSplices can even show more light on the
other side “gainer”other side “gainer”
• This is an illusion caused by increasedThis is an illusion caused by increased
scattering on the other sidescattering on the other side
• Splice loss uncertainty up to 0.8 dBSplice loss uncertainty up to 0.8 dB
12. Types of OTDRTypes of OTDR
Full-sizeFull-size
• Complex, powerful,Complex, powerful,
expensiveexpensive
Mini-OTDRMini-OTDR
• Fewer featuresFewer features
Fault FinderFault Finder
• Simplified, showsSimplified, shows
distance to a faultdistance to a fault
Links Ch 17c, d, eLinks Ch 17c, d, e
13. Visual Cable Tracers andVisual Cable Tracers and
Visual Fault LocatorsVisual Fault Locators
Cable tracer is just a flashlightCable tracer is just a flashlight
VFL uses an LED or Laser source to getVFL uses an LED or Laser source to get
more light into the fibermore light into the fiber
• Useful to test a fiber for continuityUseful to test a fiber for continuity
• To check to make sure the correct fiber isTo check to make sure the correct fiber is
connectedconnected
• With bright sources, you can find the break byWith bright sources, you can find the break by
looking for light shining through the jacketlooking for light shining through the jacket
Visible light only goes 3-5 kmVisible light only goes 3-5 km
through fiberthrough fiber
• Images from links Ch 17 e & fImages from links Ch 17 e & f
14. Fiber IdentifiersFiber Identifiers
Bends the fiber toBends the fiber to
detect the lightdetect the light
Can be used on liveCan be used on live
fiber withoutfiber without
interrupting serviceinterrupting service
Can detect a specialCan detect a special
modulated tone sentmodulated tone sent
down a fiberdown a fiber
• Image from tecratools.com (linkImage from tecratools.com (link
Ch 17d)Ch 17d)
15. Optical Continuous WaveOptical Continuous Wave
Reflectometer (OCWR)Reflectometer (OCWR)
Measures optical return lossMeasures optical return loss
(reflectance) of connectors(reflectance) of connectors
Inaccurate on installed systemsInaccurate on installed systems
because it includes backscatter andbecause it includes backscatter and
all sources of reflectanceall sources of reflectance
• See link Ch 17hSee link Ch 17h
Cable to
be
Tested
16. MicroscopeMicroscope
Used to inspectUsed to inspect
fibers andfibers and
connectorsconnectors
• Particularly duringParticularly during
epoxy-polish processepoxy-polish process
Image from link Ch 17gImage from link Ch 17g
17. TalksetTalkset
Telephone callsTelephone calls
over unused fibersover unused fibers
Rarely neededRarely needed
now that we havenow that we have
cellphonescellphones
• See link Ch 17iSee link Ch 17i
18. AttenuatorsAttenuators
Simulates the loss of aSimulates the loss of a
long fiber runlong fiber run
Variable attenuatorsVariable attenuators
allow testing a networkallow testing a network
to see how much loss itto see how much loss it
can withstandcan withstand
Can use a gap, bending,Can use a gap, bending,
or inserting opticalor inserting optical
filtersfilters
• Image from link Ch 17jImage from link Ch 17j
19. Reference CablesReference Cables
Test cables are needed to connectTest cables are needed to connect
the cables to be tested to the testthe cables to be tested to the test
instrumentsinstruments
Must have correct connectors, beMust have correct connectors, be
clean, and high-quality (low loss)clean, and high-quality (low loss)
Use high-quality mating adaptersUse high-quality mating adapters
• Ceramic or metal – not plasticCeramic or metal – not plastic
• Singlemode rated are most accurateSinglemode rated are most accurate
20. Optical Power LevelsOptical Power Levels
Detectors are Silicon, Germanium, orDetectors are Silicon, Germanium, or
Indium-Gallium-Arsenide semiconductorsIndium-Gallium-Arsenide semiconductors
Network TypeNetwork Type WavelengthWavelength Power Range (dBm)Power Range (dBm)
TelecomTelecom 1330, 15501330, 1550 +3 to -45+3 to -45
Telecom DWDMTelecom DWDM 15501550 +20 to -30+20 to -30
DataData 665, 790, 850,665, 790, 850,
13001300
-10 to -30-10 to -30
CATVCATV 1300, 15501300, 1550 +10 to -6+10 to -6
21. CalibrationsCalibrations
NIST is a standards laboratoryNIST is a standards laboratory
• Offers power calibration services at 850,Offers power calibration services at 850,
1300, and 1550 nm wavelengths1300, and 1550 nm wavelengths
• Instruments should be returned to theInstruments should be returned to the
manufacturer for calibration annuallymanufacturer for calibration annually
22. UncertaintiesUncertainties
Absolute power: 5% or 0.2 dBAbsolute power: 5% or 0.2 dB
Insertion loss: 0.5 dB or moreInsertion loss: 0.5 dB or more
OTDR: up to several dBOTDR: up to several dB
Optical return loss: 1 dB or moreOptical return loss: 1 dB or more
• Although meters show a reading withAlthough meters show a reading with
hundredths of a decibel, they don’t meanhundredths of a decibel, they don’t mean
anythinganything
A 2.13 dB loss might well re-measure as 2.54 dBA 2.13 dB loss might well re-measure as 2.54 dB
23. Optical Fiber TestingOptical Fiber Testing
Before installationBefore installation
• Test continuity with cable tracer or VFLTest continuity with cable tracer or VFL
Measure attenuation withMeasure attenuation with cutback methodcutback method
• Cut offCut off
knownknown
length,length,
measuremeasure
powerpower
increaseincrease
24. Sources for Loss MeasurementsSources for Loss Measurements
Most multimode systems use LEDMost multimode systems use LED
sourcessources
• High-speed multimode often usesHigh-speed multimode often uses
VCSELs (1 Gbps and higher)VCSELs (1 Gbps and higher)
• See link Ch 17kSee link Ch 17k
Singlemode systems use laserSinglemode systems use laser
sourcessources
Test with the source you will reallyTest with the source you will really
useuse
• BUT Argilent says you should test allBUT Argilent says you should test all
Multimode with LEDs (link Ch 17l)Multimode with LEDs (link Ch 17l)
25. Modal Effects in Multimode FiberModal Effects in Multimode Fiber
Mode scramblers mixMode scramblers mix
modes to equalize power inmodes to equalize power in
all modesall modes
• Can be made with a sectionCan be made with a section
of step-index fiberof step-index fiber
Mode filters remove higher-Mode filters remove higher-
order modes to reachorder modes to reach
equilibrium modalequilibrium modal
distributiondistribution
• Can be made with a mandrelCan be made with a mandrel
wrapwrap
26. Modal Effects in Singlemode FiberModal Effects in Singlemode Fiber
Singlemode fibers shorter than 10Singlemode fibers shorter than 10
meters may have extra modesmeters may have extra modes
• Use a launch cord to avoid that problemUse a launch cord to avoid that problem
27. OTDR Pulse WidthOTDR Pulse Width
Longer pulses can see further down the cableLonger pulses can see further down the cable
because they have more lightbecause they have more light
But they have less accuracy finding locationsBut they have less accuracy finding locations
• From link Ch 17aFrom link Ch 17a
28. OTDR UncertaintiesOTDR Uncertainties
Dead zoneDead zone
• Nothing can be measured for the firstNothing can be measured for the first
100 meters or so100 meters or so
Distance ResolutionDistance Resolution
• Two events too close together cannot beTwo events too close together cannot be
resolvedresolved
• Especially with long pulsesEspecially with long pulses
29. OTDR Distance ErrorsOTDR Distance Errors
Speed of light in fiberSpeed of light in fiber
• May not be exactly what the OTDRMay not be exactly what the OTDR
expects, distorting distancesexpects, distorting distances
Slack in fiberSlack in fiber
• OTDR measures length along the fiber,OTDR measures length along the fiber,
which is usually 1% - 2% longer thanwhich is usually 1% - 2% longer than
the length along the cablethe length along the cable
30. OTDR Loss ErrorsOTDR Loss Errors
Joining two fibers with differentJoining two fibers with different
backscatter coefficients will cause:backscatter coefficients will cause:
• Too high a loss when measured in oneToo high a loss when measured in one
directiondirection
• Too low a loss in the other directionToo low a loss in the other direction
For accurate loss measurements,For accurate loss measurements,
measure from both ends andmeasure from both ends and
average the resultsaverage the results
31. OTDR GhostsOTDR Ghosts
Secondary reflection appears at double the realSecondary reflection appears at double the real
cable lengthcable length
Using index-matching gel will eliminate ghostsUsing index-matching gel will eliminate ghosts
32. DispersionDispersion
Multimode fibers suffer fromMultimode fibers suffer from modalmodal
dispersiondispersion
All fibers suffer fromAll fibers suffer from chromatic dispersionchromatic dispersion
• Because different wavelengths travel atBecause different wavelengths travel at
different speeds, and no source is completelydifferent speeds, and no source is completely
monochromaticmonochromatic
In very long singlemode networks,In very long singlemode networks,
polarization mode dispersionpolarization mode dispersion also mattersalso matters
33. Bandwidth TestersBandwidth Testers
There is a new unit available to testThere is a new unit available to test
bandwidth in the field, but it is notbandwidth in the field, but it is not
commonly done yet (link Ch 17 k)commonly done yet (link Ch 17 k)
Input
Output
34. Connector Insertion Loss TestConnector Insertion Loss Test
This test gives the typical loss of a connectorThis test gives the typical loss of a connector
typetype
35. Modal DistributionModal Distribution
The insertion loss testThe insertion loss test
• FOTP-34 by the TIAFOTP-34 by the TIA
Three options of modal distributionThree options of modal distribution
• EMD or steady stateEMD or steady state
After a mandrel wrapAfter a mandrel wrap
• Fully filledFully filled
After a mode scramblerAfter a mode scrambler
• Any other specified conditionsAny other specified conditions
36. MicroscopesMicroscopes
Used to inspect the ends of polishedUsed to inspect the ends of polished
connectorsconnectors
Helpful to view the connector at anHelpful to view the connector at an
angle while lighting it from the sideangle while lighting it from the side
Only defects over the core reallyOnly defects over the core really
mattermatter
37. Optical Return Loss in ConnectorsOptical Return Loss in Connectors
A pair of glass-air interfaces forA pair of glass-air interfaces for
nonphysical contact connectors withoutnonphysical contact connectors without
index-matching gelindex-matching gel
• 4% reflectance – loss of 0.3 dB due to4% reflectance – loss of 0.3 dB due to
reflectancereflectance
PC connectors can have a reflectance ofPC connectors can have a reflectance of
1% or an ORL of 20 dB1% or an ORL of 20 dB
• Much less with Angled PC connectors – 40 toMuch less with Angled PC connectors – 40 to
60 dB60 dB
Reflectance can be a problem in highReflectance can be a problem in high
bitrate singlemode systemsbitrate singlemode systems
38. Basic Cable Loss TestBasic Cable Loss Test
Test FOTP-171Test FOTP-171
• Measure power through launch cableMeasure power through launch cable
• Then add cable to testThen add cable to test
This tests only one connector – turn theThis tests only one connector – turn the
cable around to test the other endcable around to test the other end
40. Single-Cable ReferenceSingle-Cable Reference
Refer to this conditionRefer to this condition
Test this wayTest this way
• EIA/TIA 568 requires thisEIA/TIA 568 requires this
• See link Ch 17mSee link Ch 17m
41. Why Use Single-Cable Reference?Why Use Single-Cable Reference?
It gives highest loss and lowestIt gives highest loss and lowest
uncertaintyuncertainty
It tests both connectors on the cableIt tests both connectors on the cable
to testto test
42. Choosing a Launch Cable forChoosing a Launch Cable for
TestingTesting
Choose cables with low lossChoose cables with low loss
• It is not necessary to get connectorsIt is not necessary to get connectors
and fiber with tighter specificationsand fiber with tighter specifications
Handle the launch cables carefullyHandle the launch cables carefully
Inspect them with a microscopeInspect them with a microscope
Keep them cleanKeep them clean
• Use splice bushings with metal orUse splice bushings with metal or
ceramic alignment sleevesceramic alignment sleeves
43. Mismatched FibersMismatched Fibers
Coupling a smaller fiber to a largerCoupling a smaller fiber to a larger
one causes only a small loss (0.3 dBone causes only a small loss (0.3 dB
or so)or so)
Connecting large fiber to small fiberConnecting large fiber to small fiber
causes a large losscauses a large loss
• Both because of diameter and numericalBoth because of diameter and numerical
apertureaperture
44. Testing the Installed Cable PlantTesting the Installed Cable Plant
Can use one-cable reference, or two-Can use one-cable reference, or two-
cable, or three-cable, but the type ofcable, or three-cable, but the type of
reference must be documentedreference must be documented
45. WavelengthsWavelengths
Usually test multimode at both 850Usually test multimode at both 850
and 1300 nm with LED sourcesand 1300 nm with LED sources
Singlemode test is usually at 1300Singlemode test is usually at 1300
nm onlynm only
• 1550 nm is sometimes required also1550 nm is sometimes required also
• For long-distance, and to show thatFor long-distance, and to show that
WDM can be performed laterWDM can be performed later
• Also shows microbends – 1550 test isAlso shows microbends – 1550 test is
much more sensitive to bending lossmuch more sensitive to bending loss
46. Optical SplitterOptical Splitter
Splits light signal from one fiber intoSplits light signal from one fiber into
two fiberstwo fibers
• Figures from tpub.com (link Ch 17n)Figures from tpub.com (link Ch 17n)
47. Couplers Can Split or CombineCouplers Can Split or Combine
You can also split one to M, orYou can also split one to M, or
combine M to 1combine M to 1
50. Wavelength Division MultiplexersWavelength Division Multiplexers
Light entering from the left containing twoLight entering from the left containing two
wavelengths is separated into the twowavelengths is separated into the two
fibers on the rightfibers on the right
Combining the two signals is also possibleCombining the two signals is also possible
Requires special equipment andRequires special equipment and
techniques to testtechniques to test
• Image from link Ch 17oImage from link Ch 17o
51. Fiber Optic AmplifiersFiber Optic Amplifiers
Boosts signal withoutBoosts signal without
converting it toconverting it to
electricityelectricity
Complicated to test,Complicated to test,
require specialrequire special
equipmentequipment
• Image from link Ch 17pImage from link Ch 17p
53. Fiber Optic DatalinksFiber Optic Datalinks
The diagram shows a single linkThe diagram shows a single link
Most networks will be bidirectionalMost networks will be bidirectional
((full duplexfull duplex) with two links working) with two links working
in opposite directionsin opposite directions
54. Bit Error RateBit Error Rate
The receiver power must be withinThe receiver power must be within
the operating rangethe operating range
• Too little power leads to high bit errorToo little power leads to high bit error
rates (wrong data at receiver)rates (wrong data at receiver)
• Too much power saturates the detectorToo much power saturates the detector
and also leads to high bit error ratesand also leads to high bit error rates
Use an attenuator in this caseUse an attenuator in this case
55. What Goes Wrong?What Goes Wrong?
Often the two fibers are connectedOften the two fibers are connected
backwards – check them with abackwards – check them with a
visual tracervisual tracer
Check receiver power levelCheck receiver power level
Check plant loss with double-endedCheck plant loss with double-ended
methodmethod
56. Don’t Use an OTDR to MeasureDon’t Use an OTDR to Measure
Plant LossPlant Loss
OTDR does not see the loss of theOTDR does not see the loss of the
end connectorsend connectors
Its power source is not the same asIts power source is not the same as
normal LAN power sourcesnormal LAN power sources
OTDR measurements are affected byOTDR measurements are affected by
backscatter coefficient which maybackscatter coefficient which may
not be the same for all the cables innot be the same for all the cables in
a networka network
57. Back ReflectionBack Reflection
Back reflection can cause networksBack reflection can cause networks
to fail even though the loss is lowto fail even though the loss is low
Power meter can’t measure reflectionPower meter can’t measure reflection
• Use an OTDR or OCWRUse an OTDR or OCWR
• Cure it by splicing in low-reflection patchCure it by splicing in low-reflection patch
cords to replace high-reflectancecords to replace high-reflectance
connectorsconnectors
• Angled PC connectors are designed toAngled PC connectors are designed to
minimize reflectance for this reason (notminimize reflectance for this reason (not
mentioned in textbook)mentioned in textbook)
58. ReliabilityReliability
Once installed, the fiber opticsOnce installed, the fiber optics
should work for a long timeshould work for a long time
People break the cable by accidentPeople break the cable by accident
• Mark where cables are buriedMark where cables are buried
• Bury a marker tape above the cableBury a marker tape above the cable
• Use orange or yellow jacket cableUse orange or yellow jacket cable
indoorsindoors
• A broken cable just behind a connectorA broken cable just behind a connector
in a patch panel is hard to findin a patch panel is hard to find
59. Source FailureSource Failure
LED in laser transmitter drops inLED in laser transmitter drops in
power as it agespower as it ages
Laser sources are feedback-stabilizedLaser sources are feedback-stabilized
so they remain constant in power tillso they remain constant in power till
they failthey fail