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Fiber Presentation

Fiber Presentation. John Swienton Fiber Specialist John.Swienton@JDSU.com 413-525-1379. Slide 1 of 163. JDSU: Global Leaders in the Markets We Serve. Communications Test & Measurement. Service Provider, Government, Business, and Home Networks. Advanced Optical Technologies.

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Fiber Presentation

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  1. Fiber Presentation John Swienton Fiber Specialist John.Swienton@JDSU.com 413-525-1379 Slide 1 of 163

  2. JDSU: Global Leaders in the Markets We Serve Communications Test & Measurement Service Provider, Government, Business, and Home Networks Advanced Optical Technologies Communications & Commercial Optical Products Cable, Telecom, Datacom, Submarine, Long Haul, Biotech, and Microelectronics Currency, Defense, Authentication, and Instrumentation

  3. CommTest Market Drivers 3

  4. Inspect Before You Connectsm

  5. Focused On the Connection Alignment Sleeve Alignment Sleeve Bulkhead Adapter Ferrule Fiber Fiber Connector Physical Contact Fiber connectors are widely known as the WEAKEST AND MOST PROBLEMATIC points in the fiber network.

  6. What Makes a GOOD Fiber Connection? Light Transmitted Core Cladding CLEAN The 3 basic principles that are critical to achieving an efficient fiber optic connection are “The 3 P’s”: • Perfect Core Alignment • Physical Contact • Pristine Connector Interface

  7. What Makes a BAD Fiber Connection? Light Back Reflection Insertion Loss Core Cladding DIRT CONTAMINATION is the #1 source of troubleshooting in optical networks. • A single particle mated into the core of a fiber can cause significant back reflection, insertion loss and even equipment damage. • Visual inspection of fiber optic connectors is the only way to determine if they are truly clean before mating them.

  8. Illustration of Particle Migration 15.1µ 10.3µ 11.8µ Core Cladding Actual fiber end face images of particle migration • Each time the connectors are mated, particles around the core are displaced, causing them to migrate and spread across the fiber surface. • Particles larger than 5µ usually explode and multiply upon mating. • Large particles can create barriers (“air gap”) that prevent physical contact. • Particles less than 5µ tend to embed into the fiber surface creating pits and chips.

  9. Types of Contamination Simplex Ribbon Oil Pits & Chips Scratches Dirt A fiber end-face should be free of any contamination or defects, as shown below: Common types of contamination and defects include the following:

  10. Contamination and Signal Performance Fiber Contamination and Its Affect on Signal Performance CLEAN CONNECTION 1 Back Reflection = -67.5 dB Total Loss = 0.250 dB DIRTY CONNECTION 3 Clean Connection vs. Dirty Connection This OTDR trace illustrates a significant decrease in signal performance when dirty connectors are mated. Back Reflection = -32.5 dB Total Loss = 4.87 dB

  11. WDM

  12. Wavelength Division Multiplexing One important advantage of glass fiber is its' ability to transmit light across a spectrum of wavelengths. This is known as Wave Division Multiplexing. Fiber 1310 nm 1550 nm 1625 nm

  13. Wave Division Multiplexing Wave Division Multiplexing or WDM combines multiple optical signals, at very high speeds, onto one fiber, significantly increasing bandwidth. 1 1 0 0 DE-MULTIPLEX MULTIPLEX 0 0 TRANSMIT 1 1 RECEIVE 1 1 0 0 0 0

  14. CWDM System Overview • Coarse Wavelength division Multiplexing for metro network • Multiplexing a given number of channels: From 4 to 18 channels as per ITU-T G.694.2 • In a limited environment: Distance range (<80km). No need for amplifiers, CD compensators… • Over a wide wavelength range (1271-1611nm) • new fibers available (All Wave …). • First step, use of 1471-1611nm • With a wide channel spacing (20nm)low cost components: Uncooled lasers, broad filters…

  15. Coarse Wave Division Multiplexing 1271 1291 1311 1331 1351 1371 1391 1411 Most common 1431 1451 1471 1491 1511 1531 1551 1571 1591 1611 PRO: Wavelengths are 20 nm apart as a cost effective solution to DWDM CON: fiber issues prevalent and # of channels fixed Wavelengths used:

  16. Wavelength Allocation • The nominal wavelength grid supporting CWDM systems has been defined by the ITU-T G.694.2 recommendation. It shows up a large wavelength range coverage (from 1271 to 1611nm) with a 20nm spacing. Attenuation (dB) L-Band O-Band E-Band S-Band C- Band Water Peak 1391 1371 1411 1291 1311 1331 1351 1431 1271 1611 1451 1591 1551 1471 1491 1511 1531 1571 Wavelength (nm)

  17. CWDM cost constraints • Central wavelength and drift tolerance • Lasers used for CWDM systems are directly modulated Distributed Feedback (DFB) lasers with bit rates of up to 2.5 Gb/s. • Relaxed specifications for • Central wavelength accuracy + wavelength drift over system lifetime. • Wide spacing of CWDM allows for a central wavelength to drift by as much as +/- 6.5 nm • MUX/DEMUX • CWDM transmission, with 20 nm channel spacing, allow using filters with reduced technical constraints compare to DWDM, driving the cost dramatically down.

  18. Comparison between CWDM and DWDM

  19. CWDM Network Testing • Installation/ Fiber qualification • Outside plant characterization including attenuation Profile (water peak qualification) • System Turn-up and Wavelength Provisioning • Wavelength-route verification (continuity check) • Insertion Loss and Power level measurement • Active element verification. • Maintenance and troubleshooting • Continuity check • Transmitter/Receivers Power Levels and drift • Fault Location

  20. Dense Wave Division Multiplexing PRO: Virtually unlimited scalability of channels number and bandwidth CON: higher equipment and maintenance cost 100Ghz spacing = 0.8 nm spacing ITU Channels C band – 100 channels L band – 100 channels 50Ghz spacing = 0.4 nm spacing ITU Channels C band – 200 channels L band – 200 channels

  21. Bands and Wavelengths “O” Band “E” Band “S” Band “C” Band “U” Band “L” Band 1400 1300 1600 1500 • O-Band - 1260nm to 1310nm • E-Band - 1360nm to 1460nm • S-Band - 1460nm to 1530nm • C-Band - 1535nm to 1565nm • L-Band - 1565nm to 1625nm • U-Band - 1640nm to 1675 nm l[nm]

  22. DWDM Network Testing • Installation/ Fiber qualification • Outside plant characterization including Attenuation Profile • System Turn-up and Wavelength Provisioning • Wavelength-route verification (continuity check) • Insertion Loss and Power level measurement • Active element verification. • Maintenance and troubleshooting • Continuity check • Transmitter/Receivers Power Levels and drift • Fault Location

  23. CWDM and DWDM on the same fiber 1471 1491 1511 1531 1551 1571 1591 1611 EVOLUTION 1431 1451 1471 1491 1511 1531 1551 1571 1591 1611 1431 1451 1471 1491 1511 C band DWDM 44 colors 1571 1591 1611

  24. C/DWDM Network Testing • Installation/ Fiber qualification • Outside plant characterization including attenuation Profile (water peak qualification) • System Turn-up and Wavelength Provisioning • Wavelength-route verification (continuity check) • Insertion Loss and Power level measurement • Active element verification. • Maintenance and troubleshooting • Continuity check • Transmitter/Receivers Power Levels and drift • Fault Location

  25. Test questions about 100GE networks • Is my OTDR 100G capable? Crazy Question. OTDRs are important in determining the challenges of a fiber with respect to loss/ back reflection and other artifacts. This is NOT rate dependent. • How do I tell if my OSA can handle 100G networks? Seriously, were you dropped on your head at birth? OSAs simply take the incoming wavelengths and, by hitting several prisms, spread the wavelengths out so the laser properties can be measured. The speed they turn on and off do not affect the measurements. • Do you have inspection templates to see if a connector can support 100G. Ok, clearly your company does not embrace random drug testing. If a connector is dirty at 10G it is dirty at 100G and beyond. • If my fiber failed Fiber Characicterization for 10 G SONET speeds what good is it? Actually, great question! Just because a fiber fails fiber characterization for 10G SONET, it will most likely carry 100GE and 400GE just fine. • What the hell is Fiber Characterization?

  26. Fiber Characterization Testing

  27. What is Fiber Characterization? • Fiber Characterization is simply the process of testing optical fibers to ensure that they are suitable for the type of transmission (ie, WDM, SONET, Ethernet) for which they will be used. • The type of transmission will dictate the measurement standards used

  28. Link Characterization vs Network Characterization Link Characterization • Performed months in advance to determine network elements’ compatibility with fiber and placement of elements • Test are OTDR, PMD, CD, AP per Tellabs Sec 2.04 Network Acceptance Test Network Characterization • Performed after network is built and OpAmps are in place and operational but wavelengths are not lit. • Tests are PMD/CD/AP and will confirm additional Dispersion added by network elements is acceptable. In Service/In Band PMD • Used when taking down a network is NOT an option like network upgrades. • No specialized lightsource needed • Will yield PMD and DGD of all wavelengths currently on your network

  29. Chromatic Dispersion – What is it ? InputPulse Output Pulse Pulse spreading • Different wavelengths = different speeds thru fiber • Value doesn’t change (ps/nm.km) • Can becompensated

  30. PMD – What is it ? • Different Polarization States = different speeds thru fiber • The difference = Differential Group Delay (DGD) • PMD = Mean value of various DGD’s Fast v2 DGD Slow External stress !! v1 • Values change constantly due to external stress (e.g., wind, temp, weight) • Compensation is complex and expensive

  31. PMD as a function of Birefringence Fiber Strain Causes Strained Fiber Perfect Fiber Stresses and Strains on the fiber changes the shape of the cladding and core. As the stresses change at various point throughout the fiber link, coupled with the polarization states constantly spinning, makes pin pointing PMD and removing the “bad” section a game of chance.

  32. Attenuation Profile = Wavelength Dependent Loss The AP of each fiber differs between fiber types and also differs from the same fiber type made in different years. The older the fiber, the more the loss. 3 2.5 2 1.5 1 .5 0 Attenuation dB/km 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Wavelength (nm)

  33. Questions John Swienton John.Swienton@JDSU.com 413-525-1379

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