Part 1: Inspection and Cleaning See the Light! Part 1: Inspection and Cleaning

Fiber Optics Key Concepts Agenda Fiber Optics Key Concepts Fiber types and Connectors Fiber Connections: the good, the bad, and the ugly Measurement Units Inspection and Cleaning Inspect Before You ConnectSM Inspect Both Sides Proactive Inspection Cleaning Best Practices Introduction to Fiber Testing Wide variety of people on the phone – need to make sure everyone is on the same page. 2

Optical Communications Communication technology, developed in the 70s, that sends optical signals down hair-thin strands of glass fiber Transmitter Receiver Light Rays Fiber Fiber optics is a communication technology developed in the 1970s and became widely deployed by the 1990s. It is now the primary transport medium in all types of telecommunications networks. Very simply, fiber optic communication transmits optical signals down very thin glass fiber strands to a receiver. 3

Optical Fiber Types 2 Types Multimode Single-mode Two basic types of fiber optic cables are used: Multimode and Single-mode. Details of how light travels down these two types of fiber will be addressed on the following two slides. Physically, both fiber types are made up of a glass core surrounded by a glass cladding. A protective buffer then covers the fiber that is typically stripped off when terminating a fiber. The core of a multimode fiber is either 50 or 62.5 microns wide. The core of a single-mode fiber is typically 9 microns wide. Both multimode and single-mode fiber cores are surrounded by a 125 micron cladding. The buffer takes the total diameter of the fiber to either 250 or 900 microns. Note that these examples show simplex fiber cables. Multi-strand fiber cables also exist. 4

Fiber Types MM Fiber carries numerous light rays (mode) simultaneously through the fiber. Light traveling through multimode fiber takes multiple paths or modes, which causes the light pulses to spread out or disperse. The result of this pulse spreading is that multimode fiber cannot carry high bit rates over long distances. Multimode fiber is typically found in local area networks working at 850 or 1300 nanometers. While the fiber optic cable itself is not significantly cheaper than single-mode fiber, the light sources are. Multimode fiber uses LEDs or VCSEL (cheap lasers) as light sources compared to lasers for single-mode fiber. Refractive index: Measures the speed of light in a material. For example, n1 and n2 are the respective refractive index of the cladding and the core, and n1<n2 is the condition for the light traveling down the fiber. Fiber channel and Ethernet are most common applications High attenuation 850 to 1300 nm transmission wavelengths Local networks (<2 km) Limited bandwidth LAN/Industry 5

Fiber carries a single light ray (mode). Fiber Types SM Fiber carries a single light ray (mode). Low attenuation 1260 to 1660 nm transmission wavelengths Access/medium/long haul networks (>200 km) Nearly infinite bandwidth Telecom/CATV FTTx CWDM/DWDM Outside plant fiber optic cable uses single-mode fiber. Working at 1310, 1550, and other wavelengths in the 1260 to 1660 nanometer range, single-mode fiber can carry very high bit rates over long distances. Because the core of the fiber is so small, light can only take a single path through it, minimizing the amount of dispersion. Single-mode fiber is also used in wavelength division multiplexing systems, which have multiple wavelengths of light traveling on the same fiber. Ethernet/FICON on SM is popular in enterprise 6

Fiber Connectors are Everywhere! Fiber optic connectors are common throughout the network as they provide the power to add, drop, move, and change the network. Local Convergence Point Buildings Network Access Points CO/Headend/MTSO Use the phrase: Moves, adds, changes Close slide with “connectors are everywhere” Feeder Cables Distribution Cables Multi-home Units Residential Drop Cables

Fiber Optic Connector Body Houses the ferrule that secures the fiber in place LC CONNECTOR Ferrule Thin cylinder where the fiber is mounted and acts as the fiber alignment mechanism Ferrule Cladding Body Core The fiber connector uses a latch and key mechanism to align the fiber and prevents the rotation of ferrules of the two mated connectors. Fiber: Cladding Glass layer surrounding the core, which prevents the signal in the core from escaping Fiber: Core The critical center layer of the fiber; the conduit that light passes through

Anatomy of Fiber Connectors Light is transmitted and retained in the CORE of the optical fiber by total internal reflection. The fiber connector end face has 3 major areas – the core, the cladding and the ferrule. Particles closer to the core will have more impact than those farther out. Fiber End Face View FERRULE – 1.25 or 2.5 mm CLADDING – 125 µm CORE – 9 µm (SM)

Single Fiber vs. Multi-Fiber Connectors SINGLE FIBER CONNECTOR MULTI-FIBER CONNECTOR White ceramic ferrule One fiber per connector Common types include SC, LC, FC, and ST Polymer ferrule Multiple fibers in linear array (for example, 8, 12, 24, 48, and 72) in single connector providing high-density connectivity Common type is MPO or MTP®

Common Single Fiber Connectors FC connector 2.5 mm ferrule Screw mechanism with key –aligned Legacy – mainly used with single-mode fibers ST Connector Twist-lock mechanism Legacy – mainly used with multimode fibers SC Connector Push-pull latching mechanism Most widely used connector today (LAN/WAN) LC Connector 1.25 mm ferrule Finger latch Fastest growing connector

The angle reduces the back-reflection of the connection. Types of End Faces PC – Physical Contact APC – Angled Physical Contact The angle reduces the back-reflection of the connection. APC connectors are used in systems where back reflection is an issue such HIGH-POWER applications. Video is typically high-power, so APC connectors are found in CATV and FTTx environments. SC - PC SC - APC 12

Focus on the Connection Bulkhead Adapter Ferrule Fiber Fiber Connector Alignment Sleeve Alignment Sleeve Physical Contact Note there are two endfaces – one in the bulkhead and one on the patch cord.

What Makes a GOOD Fiber Connection? The 3 basic principles that are critical to achieving an efficient fiber optic connection are “The 3 Ps”: Light Transmitted Perfect Core Alignment Physical Contact Pristine Connector Interface Core Cladding CLEAN Today’s connector design and production techniques have eliminated most of the challenges to achieving core alignment and physical contact.

What Makes a BAD Fiber Connection? Today’s connector design and production techniques have eliminated most of the challenges to achieving core alignment and physical contact. The remaining challenge is maintaining a pristine end face. As a result, CONTAMINATION is the No. 1 reason for 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. Light Back Reflection Insertion Loss Core Cladding Emphasis on Contamination being the No. 1 reason for troubleshooting DIRT

Measurement Units dBm unit is decibels relative to 1 mW of power dBm is an ABSOLUTE measurement dB is a RELATIVE measurement 1 mW = 0 dBm Tx Relative Power (dB) =10*Log 2 dB 1 dB Loss = 8 dB Absolute Power (dBm) =10*Log 5 dB When we move into the section that discusses testing, the difference between dB and dBm will become critical. Simply put, dBm is an ABSOLUTE measurement: 1 mW equals 0 dBm, while dB is a relative measurement. The diagram on the right side of the slide illustrates this. At the top a transmitter is generating 0dBm – an absolute value. At the bottom a receiver is receiving -8 dBm, again an absolute value. Between the transmitter and the receiver are two fiber optic cables and a single fiber connector that, combined, create a loss of 8 dB—a relative value. In other words, loss is never referred to in dBm because it is always a relative value. We could change the transmitted level to +8 dBm and the received level would then become 0 dBm, because the relative amount of loss is still 8 dB. Make note of loss shown at connection – want connector to be about .75dB of loss – most volatile point -8 dBm Rx 0 dBm -3 dBm -20 dBm -40 dBm 1 mW 0.5 mW 0.01 mW 0.0001 mW 16

What is the output power of the transmitter? Optical Loss Budget Transmitter Receiver Light Rays Fiber What is the output power of the transmitter? What is the sensitivity of the receiver? The difference is the maximum amount of LOSS allowable for the optical transmission line. When installing a fiber network, network topology and equipment specifications must be considered. One of the major parameters requiring measurement is optical loss budget, or end-to-end optical link loss. When calculating the optical loss budget of a fiber link, the source, detector, and optical transmission line must be considered. Optical loss budget must account for both link loss and system power margins. These power margins cover allowances for the effects of environment, aging, and eventual repairs.

Contamination and Signal Performance FIBER CONTAMINATION AND ITS EFFECT ON SIGNAL PERFORMANCE CLEAN CONNECTION Back Reflection = -67.5 dB Total Loss = 0.250 dB 1 DIRTY CONNECTION Back Reflection = -32.5 dB Total Loss = 3.2 dB 3 CLEAN Connection vs. DIRTY Connection This OTDR trace illustrates a significant decrease in signal performance when dirty connectors are mated. Make connection to link budget. Make the point that where the contamination is makes a difference

Illustration of Particle Migration 11.8µ 15.1µ 10.3µ Core Cladding Actual fiber end face images of particle migration Emphasis on what happens over time with a little bit of contamination never being caught. Even though the contamination at the beginning was not in the core, it can easily migrate to the core. Each time connectors are mated, particles around the core become displaced, causing them to migrate and spread across the fiber surface. Particles larger than 5 µm usually explode and multiply upon mating. Large particles can create barriers (air gaps) that prevent physical contact. Particles smaller than 5 µm tend to embed into the fiber surface creating pits and chips.

Particle Migration and Signal Performance -70 -60 -50 -40 -30 -20 Baseline/ Initial Contamination 1st Mating 2nd Mating 3rd Mating Actual fiber end face images of particle migration Importance is where the contamination is. For each successive mating, actual dB values increase as signal performance decreases Dirt particles near or on the fiber core significantly affect signal performance

PITS (permanent damage) Dirt Damages Fiber! Mating dirty connectors embeds the debris into the fiber. Light Back Reflection Insertion Loss Core Cladding PITS (permanent damage) DIRT Mating force of 2.2 lb over 200 um diameter gives 45,000 psi. Once embedded debris is removed, pits and chips remain in the fiber. These pits can also prevent transmission of light, causing back reflection, insertion loss and damage to other network components. Most connectors are not inspected until the problem is detected… AFTER permanent damage has already occurred.

Types of Contamination Fiber end faces should be free of any contamination or defects, as shown below: Single-mode Fiber Common types of contamination and defects include the following: Dirt Oil Pits & Chips Scratches

Contamination Categories LOOSE Most contamination comes from dry particles that have fallen onto the end face or have been “placed” there during handling BONDED Most stubborn particles are held in place with grease, oils, or dried residue from a wet cleaning process MATED Particles on the end face of a connector can also become embedded into the glass if mated with another connector CONTAMINATION MUST BE CLEANED from the end face prior to mating in order to optimize the efficiency of an optical signal or interconnect

Inspection and Cleaning

Inspect Before You Connectsm Follow the simple “INSPECT BEFORE YOU CONNECT” process to ensure fiber end faces are clean prior to mating connectors. 25

Inspect, Clean, Inspect, and Go! Fiber inspection and cleaning are SIMPLE steps with immense benefits. 1 Inspect ■ Use a probe microscope to INSPECT the fiber. – If the fiber is dirty, go to Step 2, Clean. – If the fiber is clean, go to Step 4, Connect. 2 Clean ■ If the fiber is dirty, use a simple cleaning tool to CLEAN the fiber surface. 3 Re-inspect 4 Connect ■ If the fiber is clean, CONNECT the connector. NOTE: Be sure to inspect both sides (patch cord “male” and bulkhead “female”) of the fiber interconnect. ■ Use a probe microscope to RE-INSPECT (confirm fiber is clean). – If the fiber is still dirty, repeat Step 2, Clean. – If the fiber is clean, go to Step 4, Connect.

Inspect and Clean Both Connectors in Pairs! Inspecting BOTH sides of the connection is the ONLY WAY to ensure the connector will be free of contamination and defects. Inspection is contact-free. Discuss or have separate slide. Patch Cord (Male) Inspection Bulkhead (Female) Inspection Patch cords are easy to access and view compared to the fiber inside the bulkhead (or test equipment or network equipment) which are frequently overlooked. The bulkhead side may only be half of the connection, but it is far more likely to be dirty and problematic.

Proactive vs. Reactive Inspection PROACTIVE INSPECTION: Visually inspect fiber connectors at every stage of handling BEFORE mating them. Connectors are much easier to clean prior to mating, before embedding debris into the fiber. REACTIVE INSPECTION: Visually inspect fiber connectors AFTER discovering a problem, typically during troubleshooting. By this time, connectors and other equipment may have suffered permanent damage. Dirty Fiber PRIOR to Mating Fiber AFTER Cleaning Fiber AFTER Mating and Numerous Cleanings Dirty Fiber PRIOR to Mating Common mistake is to reactively inspect fiber endfaces 28

Benefits of Proactive Inspection PROACTIVE INSPECTION is quick and easy, with indisputable benefits Reduce Network Downtime Active network = satisfied customers Reduce Troubleshooting Prevent costly truck rolls and service calls Optimize Signal Performance Network components operate at highest level of performance Prevent Network Damage Ensure longevity of costly network equipment 29

Cleaning Best Practices Many tools exist to clean fiber Many companies have their own “best practices” Dry clean first. If that does not clean, then try wet cleaning. Always finish with dry cleaning! Whatever cleaning equipment you use, make sure it is designed for fiber optic cleaning.

Testing

Test! Basic Tests Advanced Tests Visual Fault Locator (VFL) Optical Insertion Loss Optical Power Levels Advanced Tests Optical Return Loss (ORL) Optical Time Domain Reflectometer (OTDR) Chromatic Dispersion (CD) Polarization Mode Dispersion (PMD) Optical Spectral Analysis (OSA)

Visual Fault Locator VFLs provide a visible red light source useful for identifying fiber locations, detecting faults due to bending or poor connectorization, and to confirming continuity. VFL sources can be modulated in a number of formats to help identify the correct VFL (where a number of VFL tests may be performed). FFL-100 FFL-050

Insertion Loss Single Direction Insertion Loss Measurement with a Source and Power Meter Reference first! Light Source Power Meter 0dB Reference Measurement Light Source Power Meter -1.5dB Jumper or patch-cord Bi-Directional LS and PM PocketClass Smart Optical - Insertion Loss Measurement 2255/45 2256/02 1, 2, or 3 jumper references can be performed – 2 jumper shown 34

Advanced Tests Optical Return Loss (ORL) Optical Time Domain Reflectometer (OTDR) Detect, locate, and measure events at any location on the fiber link Fiber Characterization Determines the services that the fiber can be carry Basic tests plus: Chromatic Dispersion (CD) Polarization Mode Dispersion (PMD) Optical Spectrum Analysis (OSA) Spectral analysis for Wavelength Division Multiplexing (WDM) systems

Wrap Up

Always “INSPECT BEFORE YOU CONNECT” Summary Always “INSPECT BEFORE YOU CONNECT” Correct testing of the fiber optic link is critical Tests range from basic VFL/OIL to advanced OTDR/PMD/CD Tests to perform depend on the network (For example, LAN, CATV, FTTx, Access, Metro, or Long Haul) JDSU CommTest provides the tools and services to ensure the performance of your fiber optic system! We are the World Leader in fiber video inspection

Making IBYC Easy ESSENTIALS TOOLS in ONE DEVICE Easy-use optimizes workflow procedures Promotes proper fiber handling practices Integrated functions and features eliminate switching between different devices Inspect bulkhead with probe Inspect patch cord with integrated patch cord microscope (PCM) Test power measurement with integrated power meter HP3-60-P4 Display System with FBP Probe

HP3-60 Display System INTEGRATED INSPECTION & TEST Patch Cord Inspect Input The new HP3-60 display system combines fiber inspection and optical power measurement into a single seamless handheld device. This unique combination makes the HP3-60 system the industry’s only solution for inspecting and testing fiber networks with one handheld device, enabling increased workflow efficiency and decreased total inspection and test time. Input for Power Meter Probe Input (for bulkhead inspection) Power Meter Display Power Meter Controls 1.8 in. Fiber Display Power Button A/B Switch (toggle between patch cord and bulkhead fiber view) Focus Control Low Battery Indicator FIT-HP3-60-P4

Full Range of Optical Inspection and Test Solutions Fiber Cleaning and Inspection Handheld Microscopes Probes Automated Analysis Visual Fault Locators PocketClass Light Sources and Power Meters SM, MM Various Wavelengths Smart Optical Testers Light Sources and Power Meters Loss Test Sets Optical Return Loss Meters Services Training/Certification On-Site Testing incl. Fiber Characterization