© 2011 JDS Uniphase Corporation | JDSU CONFIDENTIAL AND PROPRIETARY INFORMATION 1 John Swienton...

© 2011 JDS Uniphase Corporation | JDSU CONFIDENTIAL AND PROPRIETARY INFORMATION 1

John Swienton Fiber [email protected]

Fiber Presentation

Slide 1 of 163


JDSU: Global Leaders in the Markets We Serve

Cable, Telecom, Datacom, Submarine, Long Haul, Biotech, and

Microelectronics

Communications & Commercial Optical

Products

Advanced Optical Technologies

Currency, Defense, Authentication, and Instrumentation

Communications Test & Measurement

Service Provider, Government, Business, and Home Networks


CommTest Market Drivers


Inspect Before You Connectsm


Focused On the Connection

Bulkhead Adapter

Fiber Connector

Alignment Sleeve

Alignment Sleeve

Physical Contact

FiberFerrule

Fiber connectors are widely known as the WEAKEST AND MOST

PROBLEMATIC points in the fiber network.


What Makes a GOOD Fiber Connection?

Perfect Core Alignment

Physical Contact

Pristine Connector Interface

The 3 basic principles that are critical to achieving an efficient fiber

optic connection are “The 3 P’s”:

Core

Cladding

CLEAN

Light Transmitted


What Makes a BAD Fiber Connection?

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.

CONTAMINATION is the #1 source of troubleshooting in optical networks.

DIRT

Core

Cladding

Back Reflection Insertion LossLight


Illustration 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.

11.8µ

15.1µ

10.3µ

Actual fiber end face images of particle migration

Core

Cladding


Types of Contamination

A fiber end-face should be free of any contamination or defects, as shown below:

Common types of contamination and defects include the following:

Dirt Oil Pits & Chips Scratches

Simplex Ribbon


Contamination and Signal Performance

Fiber Contamination and Its Affect on Signal PerformanceCLEAN CONNECTION

Back Reflection = -67.5 dBTotal Loss = 0.250 dB

11

DIRTY CONNECTION

Back Reflection = -32.5 dBTotal Loss = 4.87 dB

33

Clean Connection vs. Dirty Connection

This OTDR trace illustrates a significant decrease in signal performance when dirty connectors are mated.


WDM


1310 nm

1550 nm

1625 nm

Fiber

Wavelength Division Multiplexing


1

0

1

0

0

1

0

1

0

1

0

0

1

0

Wave Division Multiplexing


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…


Coarse Wave Division Multiplexing

12711291131113311351137113911411

Most common

1431145114711491151115311551157115911611

PRO: Wavelengths are 20 nm apart as a cost effective solution to DWDMCON: fiber issues prevalent and # of channels fixed

Wavelengths used:


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.

O-Band E-Band S-Band C- Band L-Band

Water Peak

1271 12911311 133113511371

1391

14111431

14511471 14911511153115511571

15911611

Wavelength (nm)

Attenuation (dB)


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.


Comparison between CWDM and DWDM


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


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 ChannelsC band – 100 channels

L band – 100 channels

50Ghz spacing = 0.4 nm spacing

ITU ChannelsC band – 200 channelsL band – 200 channels


[nm]

“C” Band

“L” Band

“O” Band

“E” Band

“S” Band

“U” Band

»C-Band - 1535nm to 1565nm

»L-Band - 1565nm to 1625nm

»U-Band - 1640nm to 1675 nm

»O-Band - 1260nm to 1310nm

»E-Band - 1360nm to 1460nm

»S-Band - 1460nm to 1530nm

1300 1400 1500 1600

Bands and Wavelengths


DWDM Network Testing

Installation/ Fiber qualification– Outside plant characterization including Attenuation Profile




CWDM and DWDM on the same fiber

14711491151115311551157115911611

EVOLUTION

1431145114711491151115311551157115911611

14311451147114911511C band DWDM 44 colors157115911611


C/DWDM Network Testing

Installation/ Fiber qualification– Outside plant characterization including attenuation Profile

(water peak qualification)




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?


Fiber Characterization Testing


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

Trans type Speed PMD Max CD Max

SONET OC-192 10 ps 1176ps/nm

Ethernet 10 Gbs 5 ps 738 ps/nm

SONET OC-768 2.5 ps 64 ps/nm


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


Chromatic Dispersion – What is it ?

Pulse spreading

Different wavelengths = different speeds thru fiber Value doesn’t change (ps/nm.km) Can be compensated

InputPulse

Output Pulse


Different Polarization States = different speeds thru fiber The difference = Differential Group Delay (DGD) PMD = Mean value of various DGD’s

PMD – What is it ?

DGD

v1

v2

Fast

Slo

w

External stress !!

Values change constantly due to external stress (e.g., wind, temp, weight)

Compensation is complex and expensive


PMD as a function of Birefringence

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.

Perfect FiberStrained Fiber

Fiber Strain Causes


0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7

3

2.5

2

1.5

1

.5

0

Attenuation Profile = Wavelength Dependent Loss


Questions

John [email protected]

413-525-1379

© 2011 JDS Uniphase Corporation | JDSU CONFIDENTIAL AND PROPRIETARY INFORMATION 1 John Swienton...

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Transcript of © 2011 JDS Uniphase Corporation | JDSU CONFIDENTIAL AND PROPRIETARY INFORMATION 1 John Swienton...