Upgrade Your Fiber Optic Diagnostics with Portable Ultra-High - - PowerPoint PPT Presentation

David Potter Luna Innovations June 2, 2020

Upgrade Your Fiber Optic Diagnostics

with Portable Ultra-High Resolution Optical Backscatter Reflectometry

Luna Innovations - Overview

Incorporated 1990 IPO 2006 Corporate HQ in Roanoke, VA Recent expansion

▪ Micron Optics – 2018 ▪ General Photonics – 2019

COMMUNICATIONS TEST

Telecom, Datacom, Aerospace/Defense

FIBER OPTIC SENSING

Aerospace, Automotive, Structures, Safety

Fiber Optic Adoption and Evolution

1980 1990 2000 2010 2020 1 cm 10 cm 1 m 10 m 100 m 1 km 10 km 100 km

Card-to-Card Backplanes Metro/Lan Data Centers Rack-to-Rack Long Haul Chip-to- Chip On Chip Optical Waveguides Aero/Defense

Length

Naval/Industrial FTTx

Deploying and Maintaining Fiber Optic Assemblies

Installation and Commissioning ▪ Proper installation ▪ Splice and connector quality ▪ Total loss budget Maintenance – Identify and Locate Issues ▪ Fiber breaks ▪ Faulty connectors ▪ Pinched/bent fiber

Higher Density More Complexity Difficult Environments and Access Costly Downtime

Short lengths (< 100 m) Multiple sections

▪ Sections/links can be < 1m

Restricted access to network Expensive downtime Harsh environmental conditions Test and diagnostics

▪ Single access ▪ Fast and precise identification ▪ Minimize ground time

Example: Fiber Optic Assemblies in Aviation

Testing Fiber Optic Assemblies

1.23 LS

Light Source Optical Power Meter

Optical Loss Test Set

Cable Assembly to Test

• Measure total loss (IL)
• Access both ends of network
• No fault location information

OTDR (Optical Time Domain Reflectometer)

• Single-ended access
• Locate reflections and loss

along assembly

• Able to map out km’s of

fiber optic network

• Limited spatial resolution

Cable Assembly to Test

OTD R

OTDR

Reflection Distance Launch cable Reference cable Reference cable

Reflections in Optical Path

Discrete, Fresnel Reflection Distributed Backscatter (Rayleigh)

Reflected Rayleigh backscatter

Transmitted Light

Scattering due to minute fluctuations in refractive index

n1 n2 Pi Pr

Transmitted Light Reflected Light

Pi

Return Loss (RL) and Insertion Loss (IL)

Return Loss (RL) = 10Log Pr Pi Insertion Loss IL = −10Log P𝑢 Pi

Pr = reflected power Pt = transmitted power Pi = incident power

Pi1 Pr1 Pt1 Typical Reflection Return Loss (RL)

Typical RL % Light Reflected

APC-APC Connection

• 65 dB

0.000032% PC-PC Connection

• 40 dB

0.01% Open flat polish to air

• 15 dB

3%

Typical Insertion Loss (IL)

Typical IL % Light Transmitted

Connector Pair <0.2 dB 96% Fusion splice <0.05 dB 99% Mechanical splice 0.3 dB 93%

Optical Time Domain Reflectometry (OTDR)

OTDR

Splice Connector pair Fiber bend Connector Fiber end

Reflectance Distance

Noise Level Light pulse

Optical Time Domain Reflectometry (OTDR)

Typical minimum OTDR dead zones (best conditions):

• Standard OTDRs: ~ 1 – 2 m (or more)
• Specialty high-resolution OTDRs: ~20 – 40 cm

Event 1 Event 2

Event Dead Zone (EDZ) Attenuation Dead Zone (ADZ)

• Indicates minimum distance that two consecutive reflective events

can be distinguished (not necessarily measured)

• Defined as width 1.5 dB down from reflective peak

1.5 dB

EDZ ADZ

• Indicates minimum distance after a reflection where loss

can be accurately measured

• Determine by distance needed for trace to return to within

0.5 dB of backscatter level

OTDR: OBR:

Optical Backscatter R eflectometer Event resolution << 1mm

What is Optical Backscatter Reflectometry (OBR)?

Splice Connector pair Bend Connector Fiber end

OBR

Reflection (dB) Distance

Noise Level

Bad Connector Splice Attenuation (dB) Distance Connector Faces <1 mm

✓ Ultra-high resolution ✓ No dead zones ✓ No launch cable ✓ Backscatter sensitivity ✓ High-precision latency measurements

OFDR Principles (1 of 2)

detector Reference Signal source

e-iω(t)t Optical Frequency Domain Reflectometry (OFDR) Principles

Reflector 1 Reflector 2

Measurement time, “t” (P)

Distance, or “fringe frequency”

P ~ cos [ω(t)∆τ]

New Tool for Field Diagnostics and Troubleshooting

OBR 6225

Highest-resolution portable reflectometer

▪ Troubleshoot and diagnose fiber optic assemblies ▪ Unmatched resolution and sensitivity ▪ Measure distributed loss and latency with high precision

Portable and rugged for field maintenance usage Easy-to-use touchscreen GUI Por table. Rugged. Ultra-High Resolution.

OBR 6225 ̶ Some Specifics

One or two optical channels Ultra-high spatial sampling resolution – down to 80 𝜈m C-band wavelength scan (centered at 1546.7 nm) Distributed RL and IL measurement, with automatic loss event detection and location Sensitivity of -129 dB Automatic self-calibration and optical alignment Water resistant and dustproof

▪ Available with IP65 and MIL-STD certifications

Ethernet and USB connectivity

Measurement length 20 m 50 m 100 m Sampling resolution 80 𝜈m 100 𝜈m 200 𝜈m Event (2-pt) resolution 160 𝜈m 200 𝜈m 400 𝜈m

OBR 6225 Interface

Measuring RL and IL

Rayleigh backscatter Rayleigh backscatter Discrete reflection event

• Connector/gap
• Bend
• Break/crack

IL (loss) measured by decrease in backscatter levels RL at a location is integration of reflectance

• ver that area

Demonstration of Portable OBR

MMF CABLE 1 MMF CABLE 2

Multi-mode conditioner

Adapter cable OBR 6225

Demonstration of Portable OBR

Measurement Example: Short SMF Jumper Cable

OBR 6225

Pinch in fiber Bad connector

Measurement Example: Short SMF Jumper Cable

Tight bend FC/APC Connector FC/APC Connector OBR adapter cable

Distinguishing Reflections

Crack at end

• f ferrule

Open face Cap

Distinguishing Reflections

Ferrule failure Open face Cap

Measure fiber skew/latency with ultra-high accuracy and precision

Measurement Accuracy Length Latency 20 m <1 mm < 0.005 ns 50 m <2 mm < 0.010 ns 100 m < 4mm < 0.020 ns

Using OBR to Measure Latency and Skew

Latency Measurement Accuracy OBR 6225

Financial trading latency certification Manufacturing quality control Delay lines Phased array radar

Measurement Example: Cable Skew/Latency Measurement

OBR 6225

1x4 Splitter 10 m Multi-Fiber Cable 4 leads staggered by ~0.2 m each

screenshots

1x4 splitter

screenshots

Fiber Lengths (m): Fiber 1 10.2438 Fiber 2 10.2494 Fiber 3 10.2358 Fiber 4 10.2457

Luna Suite of OFDR-Based Test and Measurement Instruments

Optical Vector Analyzer

OVA 5000 OBR 4600

• Complete characterization
• f optical components
• All-parameter analysis in

single scan

• OFDR time domain optional
• Sampling resolution down to

10 microns

• Polarization and phase

measurements

• Full-functionality for lab and

manufacturing applications

• Component analyzer with

reflection (OBR) and transmission measurements

• Fast and robust system
• ptimized for production test

Luna 6415

Component Analyzer Optical Backscatter Reflectometers (OBRs)

OBR 6225

• Micron-level resolution in

portable and rugged package

• Ideal for field maintenance

applications

Summary / Q&A

OBR: OTDR-like measurements

▪ Ultra-high spatial resolution (<< 1 mm) ▪ Ultra-high sensitivity

Portable form factor for field and maintenance of short-haul networks Website: www.lunainc.com Email: solutions@lunainc.com Sales Support: 1.866.586.2682 David’s email: potterd@lunainc.com