mailto:nicholas.gagnon@exfo.com

2© 2016 EXFO Inc. All rights reserved.

INTRA–DC TRANSCEIVERS FORECASTS

Information from Informa PLC

25G server ports begin to ramp in 2016

40G sustains in 2016, continues with rest of market as web-scales jump to 100G

3© 2016 EXFO Inc. All rights reserved.

COMING TO THE RESCUE: WBMMF

Wide Band Multimode Fiber

8 fibers at 850 nm

2 fibers at 850 nm

880 nm

910 nm

940 nm

4© 2016 EXFO Inc. All rights reserved.

40G-100G REQUIREMENTS: IEEE 802.3BA

OM4 fiber IL max. requirement and reach performance

will be the same for WBMMF

5© 2016 EXFO Inc. All rights reserved.

ORL IS IMPORTANT TOO

-30 dB is a more realistic target for 25G+ line rate. Bad

reflection close to active equipment can be bad

-20dB won’t allow you to detect any potential Optical

Return Loss problem

6© 2016 EXFO Inc. All rights reserved.

TIGHT BUDGET AND MM IS CHALLENGING

Core diameter differences

Numerical Aperture differences

Core/Cladding concentricity errorFiber Mismatch

Light source/light coupled into the

fiber

7© 2016 EXFO Inc. All rights reserved.

OM4 PERFORMANCES REQUIREMENTS

TIA-492AAAD specifications for OM4 Fiber, September 2009

A core concentricity of 2 microns for a 50 micron

core fiber produces an attenuation of 0.47 dB

8© 2016 EXFO Inc. All rights reserved.

LAUNCH CONDITIONS: CONNECTOR OFF-SET

LED

VCSEL

FP-LaserModCon

© 2016 EXFO Inc. All rights reserved. 9

THE MANDREL WRAP AS A MODE CONDITIONERPrevious technique used before Encircled Flux

On the LS side wrap the TC

around 5 times

Measurement variability due to:

#1 Mode power distribution

#2 MM fiber characteristics

10© 2016 EXFO Inc. All rights reserved.

ENCIRCLED FLUX (EF) TEMPLATE

IEC 61280-4-1 Ed 2.0, Fibre-optic communication subsystem test procedure –

Part 4-1:Installed cable plant – Multimode attenuation measurement (Belden)

10GbE fiber-optic testing, requires Encircled Flux (EF) metric, slightly under-filled, launching conditions to satisfy the required

REPEATABILITY, REPRODUCIBILITY and UNCERTAINTYand provides good correlation between the loss and connector lateral off-set

11© 2016 EXFO Inc. All rights reserved.

LSPM – EF compliant

OTDR – EF compliant

ATTENUATION MEASUREMENTS METHODS

MMF Link

MLC

850 nm -

1300 nm

Laser

Variable Mode

Conditioner

Speckle

Scrambler

Launching

CableModal

interference

noise reduction

850 nm -

1300 nm

Power meter

MMF Link

MLC

850 nm - 1300 nm

OTDR

Variable Mode

Conditioner

Speckle

Scrambler

Launching

CableModal

interference

noise reduction

MLC: Mode Launch Conditions

12© 2016 EXFO Inc. All rights reserved.

1- OFL/ Mandrel Wrap per TIA-426- 14-A, Method B

2- Encircled Flux TIA-426-14-B, Annex A

COMPARATIVE OLTS MEASUREMENTS

Source: Optical loss testing in the field is not as simple as it seems, Belden (2011)

13© 2016 EXFO Inc. All rights reserved.

IT’S A WRAP.

1. Wide Band Multimode Fiber (WBMMF) and SWDM4

transceivers shall develop a competitive and affordable 40G-

100G proposition on both CAPEX and OPEX sides

2. Using a Mandrel can result in a large measurement variability

3. Encircled Flux (EF) metric for MMF insures the required

testing REPEATABILITY, REPRODUCIBILITY and

UNCERTAINTY in tighter budget situation such as IEEE

802.3ah 40G-100G requirements

14© 2016 EXFO Inc. All rights reserved.

VISIT LINKED-IN GROUP: DATA CENTER FIBER

DATA CENTER FIBERVendor agnostic forum

https://www.linkedin.com/grp/home?gid=8424957