Keysight Technologies N4373D User manual

Keysight N4373D
Lightwave Component
Analyzer
User’s Guide

Notices
©Keysight Technologies 2017
No part of this manual may be reproduced
in any form or by any means (including
electronic storage and retrieval or transla-
tion into a foreign language) without prior
agreement and written consent from Key-
sight Technologies, Inc. as governed by
United States and international copyright
laws.
Keysight Technologies, Deutschland
GmbH Herrenberger Straße 130
71034 Böblingen, Germany.
Manual part number
4373D-90A02
Edition
Edition 5.0, October 2017
Subject matter
The material in this document is subject to
change without notice.
Keysight Technologies makes no warranty
of any kind with regard to this printed
mate-rial, including, but not limited to, the
implied warranties of merchantability and
fitness for a particular purpose.
Keysight Technologies shall not be liable
for errors contained herein or for
incidental or consequential damages in
connection with the furnishing,
performance, or use of this material.
Printing history
New editions are complete revisions of the
guide reflecting alterations in the function-
ality of the instrument. Updates are occa-
sionally made to the guide between
editions. The date on the title page
changes when an updated guide is pub-
lished. To find out the current revision of
the guide, or to purchase an updated guide,
contact your Keysight Technologies repre-
sentative.
Warranty
This Keysight Technologies instrument
prod-uct is warranted against defects in
material and workmanship for aperiod of
one year from date of shipment. During the
warranty period, Keysight will, at its
option, either repair or replace products
that prove to be defective.
For warranty service or repair, this product
must be returned to a service facility desig-
nated by Keysight.Buyer shall prepay ship-
ping charges to Keysight and Keysight shall
pay shipping charges to return the product
to Buyer. However, Buyer shall pay all ship-
ping charges, duties, and taxes for products
returned to Keysight from another country.
Keysight warrants that its software and
firm-ware designated by Keysight for use
with an instrument will execute its
programming instructions when properly
installed on that instrument. Keysight does
not warrant that the operation of the
instrument, software, or firmware will be
uninterrupted or error free.
Limitation of warranty
The foregoing warranty shall not apply to
defects resulting from improper or inade-
quate maintenance by Buyer, Buyer-sup-
plied software or interfacing, unauthorized
modification or misuse, operation outside
of the environmental specifications for the
product, or improper site preparation or
maintenance.
No other warranty is expressed or implied.
Keysight Technologies specifically
disclaims the implied warranties of
Merchantability and Fitness for a
Particular Purpose.
Exclusive remedies
The remedies provided herein are Buyer’s
sole and exclusive remedies. Keysight
Tech-nologies shall not be liable for any
direct, indirect, special, incidental, or
consequen-tial damages whether based
on contract, tort, or any other legal theory.
Assistance
Product maintenance agreements and
other customer assistance agreements are
available for Keysight Technologies prod-
ucts. For any assistance contact your
near-est Keysight Technologies Sales and
Service Office.
Certification
Keysight Technologies Inc. certifies that this
product met its published specifications at
the time of shipment from the factory.
Keysight Technologies further certifies
that its calibration measurements are
traceable tothe United States National
Institute of Standards and Technology,
NIST tothe extent allowed by the
Institutes’s calibration facility, and to the
calibration facilities of other International
Standards Organization members.
ISO 9001 certification
Produced to ISO 9001 international quality
system standard as part of our objective of
continually increasing customer satisfac-
tion through improved process control.

Keysight N4373D Lightwave Component Analyzer, User’s Guide 3
Introduction 7
Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
General Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Safety symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Line power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Optical Test Set Front and Rear Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2-port PNA version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4-port PNA version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Rear panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Getting Started 23
Unpacking the Lightwave Component Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Mounting the Test Set and the Network Analyzer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Preparing the Network Analyzer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Preparing the Test Head. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Mount the Test Head and the network analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Setting Up the Lightwave Component Analyzer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Using the correct connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Enabling and disabling the laser output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Starting the LCA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Accessing the User’s Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Performance Quick Check 37
Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Network analyzer settings and electrical calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Verifying your Electrical Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Verifying the Optical Connections and Optical CW Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Verifying the Electrical Connection and Electro-optical Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Measurement Concepts 49
General Measurement Techniques and Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
EO measurements (lasers, modulators) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
OE measurements (photodiodes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
OO measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Signal Relationships in Opto-electric Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

4Keysight N4373D Lightwave Component Analyzer, User’s Guide
Single-Ended Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Differential Measurements (applies to 4-port PNA only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Differential OE measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Differential EO measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Differential results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Calibration Concept. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Triggering Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Measuring at Different Wavelengths and with the External Optical Source Input . . . . . . . . . . . . . . . . . . . . 65
EO measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
OE measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
OO measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
User Interface Reference 67
The LCA Function Keys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Default and Advanced Measurement Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Saving and Loading Setups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Saving setups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Loading setups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
The Measurement Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Measure Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
LCA System Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Optical Path Deembedding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
RF Path Deembedding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Laser Source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Receiver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
RF Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Reset UI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Making Measurements 83
Starting the Lightwave Component Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Calibrating the Network Analyzer before Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Measuring Opto-Electrical (OE) Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Initializing the OE measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Making single-ended OE measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Making differential OE measurements (applies to 4-port PNA only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Keysight N4373D Lightwave Component Analyzer, User’s Guide 5
Measuring Electro-Optical (EO) Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Initializing the EO measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Making single-ended EO measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Making differential EO measurements (applies to 4-port PNA only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Returning to Electrical Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Measuring Optical-Optical (OO) Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Initializing the OO measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Making OO measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Measuring Optical Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Maintenance 107
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Why is it important to clean optical devices?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
What do I need for proper cleaning? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Preserving connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Cleaning instrument housings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Which cleaning procedure should I use for optical components and connectors? . . . . . . . . . . . . . . . 115
Replacing the Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Troubleshooting 125
Checking the Operation of the Lightwave Component Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Event Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Reinstalling and Updating the Software 129
Backing Up your LCA Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Reinstalling the LCA Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Updating the LCA software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Reinstalling the LCA software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Definition of Terms 135
Definition of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

6Keysight N4373D Lightwave Component Analyzer, User’s Guide
Specifications 143
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Specifications (guaranteed). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Typical values (characteristics) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
General characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Transmitter and Receiver Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Specifications for Electrical to Optical Measurements at 1310 nm (E/O Mode) . . . . . . . . . . . . . . . . . 148
Specifications for Electrical to Optical Measurements at 1550 nm (E/O Mode) . . . . . . . . . . . . . . . . . 149
Specifications for Optical to Electrical Measurements at 1310 nm (O/E Mode) . . . . . . . . . . . . . . . . . 150
Specifications for Optical to Electrical Measurements at 1550 nm (O/E Mode) . . . . . . . . . . . . . . . . . 151
Specifications for Optical to Optical Measurements at 1310 nm (O/O Mode) . . . . . . . . . . . . . . . . . . . 152
Specifications for Optical to Optical Measurements at 1550 nm(O/O Mode). . . . . . . . . . . . . . . . . . . . 153
Specifications for Electrical-Electrical Measurements (E/E Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Group delay uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
General Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Mechanical Outline Drawings, options 2x0, 2x1, 2x2 and 2x9 (dimensions in mm) . . . . . . . . . . . . . . 157
Mechanical Outline Drawings, options 4x0, 4x1, 4x2 and 4x9 (dimensions in mm) . . . . . . . . . . . . . . 158
Regulatory and Warranty Information 159
Regulatory Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Remove all doubt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Phone or Fax. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Keysight online information's: .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............. . . . . . . . . 165
Ordering Information 167
Index 171

Introduction
Keysight N4373D Lightwave Component Analyzer, User’s Guide 7
1
Introduction
Documentation 8
General Safety Considerations 9
Optical Test Set Front and Rear Panels 16

Introduction
8Keysight N4373D Lightwave Component Analyzer, User’s Guide
Documentation
The documentation for the Keysight N4373D
Lightwave Component Analyzer consists of
•The documentation for the Keysight network analyzer.
This documentation is on the hard disk of the network
analyzer. Refer to it for using the network analyzer for
electrical to electrical measurements, or for the configuration
of the network analyzer.
•The documentation for the optical test set and the Lightwave
Component Analyzer application.
Refer to this documentation for information on using the
optical test set, together with the network analyzer, for
optical to optical, electrical to optical and optical to electrical
measurements, or for setting up your lightwave component
analyzer.

Introduction
Keysight N4373D Lightwave Component Analyzer, User’s Guide 9
General Safety Considerations
This product has been designed and tested in accordance with
the standards listed on the manufacturer’s Declaration of
Conformity (see page 161), and has been supplied in a safe
condition. The documentation contains information and
warnings that must be followed by the user to ensure safe
operation and to maintain the product in a safe condition.
Safety symbols
CAUTION
The caution sign denotes a hazard. It calls attention to a
procedure which, if not correctly performed or adhered to, could
result in damage to or destruction of the product. Do not proceed
beyond a caution sign until the indicated conditions are fully
understood and met.
WARNING
The warning sign denotes a hazard. It calls attention to a
procedure which, if not correctly performed or adhered to, could
result in injury or loss of life. Do not proceed beyond a warning
sign until the indicated conditions are fully understood and met.

Introduction
10 Keysight N4373D Lightwave Component Analyzer, User’s Guide
Instrument markings
The instruction manual symbol. The product is
marked with this warning symbol when it is necessary
for the user to refer to the instructions in the manual.
The laser radiation symbol. This warning symbol is
marked on products which have a laser output.
The Off-On symbols are used to mark the positions of
the instrument power operating switch.
The recycling symbol indicates the general ease with
which the instrument can be recycled.
The C-Tick mark is the certification mark of the
Australian Communications Authority.
The CE mark is the conformity marking of the
European Community.
The CSA mark is a the certification mark of the
Canadian Standards Association.
WARNING
If this product is not used as specified, the protection provided by
the equipment could be impaired. This product must be used in a
normal condition (in which all means for protection are intact)
only.
WARNING
No operator serviceable parts inside. Refer servicing to qualified
service personnel. To prevent electrical shock do not remove
covers.
WARNING
This is a Safety Class 1 Product (provided with protective earth).
The mains plug shall only be inserted in a socket outlet provided
with a protective earth contact. Any interruption of the protective
conductor inside or outside of the instrument is likely to make the
instrument dangerous. Intentional interruption is prohibited.
WARNING
To prevent electrical shock, disconnect the instrument from mains
before cleaning. Use a dry cloth or one slightly dampened with
water to clean the external case parts. Do not attempt to clean
internally.

Introduction
Keysight N4373D Lightwave Component Analyzer, User’s Guide 11
WARNING
Using controls or adjustments or performing procedures other
than those specified in the documentation supplied with your
equipment can result in hazardous radiation exposure.
CAUTION
This product complies with overvoltage Category II and Pollution
Degree 2.
CAUTION
Ventilation requirements: When installing the product in a
cabinet, the convection into and out of the product must not be
restricted. The ambient temperature (outside the cabinet) must be
less than the maximum operating temperature of the product by
4 °C for every 100 watts dissipated in the cabinet. If the total
power dissipated in the cabinet is greater than 800 watts, then
forced convection must be used.
CAUTION
Install the instrument so that the power switch is readily
identifiable and is easily reached by the operator. This is the
instrument disconnecting device. It disconnects the mains circuit
from the mains supply before other parts of the instrument.
Alternatively, an externally installed switch or circuit breaker
(which is readily identifiable and is easily reached by the
operator) may be used as a disconnecting device.
CAUTION
Always use the three-prong AC power cord supplied with this
instrument. Failure to ensure adequate earth grounding by not
using this cord may cause instrument damage.
CAUTION
This instrument has autoranging line voltage input. Be sure the
supply voltage is within the specified range.

Introduction
12 Keysight N4373D Lightwave Component Analyzer, User’s Guide
Initial safety information
The laser source used in the Lightwave Component Analyzer is
classified as Class 1M according to IEC 60825-1/2007.
All laser sources comply with 21 CFR 1040.10 except for
deviations pursuant to Laser Notice No. 50, dated 2007-06-24.
Laser Safety
Laser class 1M label
Figure 1 Class 1M Safety Label
A sheet of laser safety labels is included. In order to meet the
requirements of IEC 60825-1 we recommend that you stick the
laser safety labels, in your language, onto a suitable location on
the outside of the instrument where they are clearly visible to
anyone using the instrument
N4373D
#100, #102 #101, #102
Laser wavelength range 1310 ± 10 nm 1550 ±20 nm
Laser Type DFB DFB
Laser Class according to IEC 60825-1 1M 1M
Maximum CW output power of LCAa
aCW output power is defined as the highest possible optical output power that the laser source
can produce at the output connector
< 15 mW < 15 mW
Maximum permissable CW output
power
52 mW 163 mW
Numerical aperture 0.1 0.1
Beam waist diameter < 10 mm< 10 mm

Introduction
Keysight N4373D Lightwave Component Analyzer, User’s Guide 13
Line power requirements
Line power connectors
In accordance with international safety standards, the
instrument has a three-wire power cable. When connected to an
appropriate AC power receptacle, this cable earths the
instrument cabinet. The type of power cable shipped with each
instrument depends on the country of destination. Please refer
to “Power Cords” on page 169 for the part numbers of available
power cables.
WARNING
Please pay attention to the following laser safety warnings:
• Under no circumstances look into the end of an optical cable
attached to the optical output when the device is operational.
The laser radiation can seriously damage your eyesight.
• Do not enable the laser when there is no fiber attached to the
optical output connector.
• The laser is enabled by the software or by pressing the laser
switch on the front panel. The laser is on when the green LED
above the switch is lit.
•The use of instruments, such as microscopes or spectacles,
with this product will increase the hazard to your eyes.
• The laser module has built-in safety circuitry which will disable
the optical output in the case of a fault condition.
• Refer servicing only to qualified and authorized personnel.
CAUTION
The Keysight N4373DLightwave Component Analyzer
complies with overvoltage category II and can operate from the
single-phase AC power source that supplies between 100 V and
240 V at a frequency in the range 50 to 60 Hz. The maximum
power consumption of the optical test set is 40 VA with all options
installed.
Please refer to the documentation for your network analyzer for
information on its line power requirements.

Introduction
14 Keysight N4373D Lightwave Component Analyzer, User’s Guide
WARNING
To avoid the possibility of injury or death, you must observe the
following precautions before switching on the instrument.
• Insert the power cable plug only into a socket outlet provided
with a protective earth contact. Do not use an extension cord
without a protective conductor. Using an extension cord
withgout a protective conductor means the instrument is not
earthed.
• Do not interrupt the protective earth connection intentionally.
•Do not remove protective covers. Operating personnel must not
remove instrument covers. Component replacement and
internal adjustments must be made only by qualified service
personnel.
• Instruments that appear damaged or defective should be made
inoperative and secured against unintended operation until they
can be repaired by qualified service personnel.
•Defective, damaged, or malfunctioning instruments must be
returned to a Keysight Technologies Service Center.
Do not operate the instrument in the presence of flammable gases
or fumes. Operation of any electrical instrument in such an
environment constitutes a definite safety hazard.

Introduction
Keysight N4373D Lightwave Component Analyzer, User’s Guide 15
Environmental information
This product is intended for indoor use only.
This product complies with the WEEE Directive (2002/96/EC)
marking requirements. The affixed label indicates that you must
not discard this electrical/electronic product in domestic
household waste.
Product Category: With reference to the equipment types in the
WEEE Directive Annex I, this product is classed as a
"Monitoring and Control instrumentation" product.
Do not dispose in domestic household waste.
To return unwanted products, contact your local Keysight
office, or see
http://about.keysight.com/en/companyinfo/environment/
takeback.shtml
for more information.

Introduction
16 Keysight N4373D Lightwave Component Analyzer, User’s Guide
Optical Test Set Front and Rear Panels
2-port PNA version
Figure 1 Front Panel
For further information on the front panel of the network
analyzer, please refer to the documentation supplied with the
network analyzer.
1 2 34 5 6 7
8
10 9
1 Power switch Turns on the optical test set.
To turn on the PNA, press the
PNA's power key.
2 Port A Caution: Be sure you do not exceed
the RF power values and DC levels
noted on the front panel of the
instrument.
This is the RF input to the
transmitter of the optical test set.

Introduction
Keysight N4373D Lightwave Component Analyzer, User’s Guide 17
3 Laser switch Press the switch to turn the laser
on (LED on), and off (LED off).
The laser can also be switched on
and off from the LCA
Measurement Setup Macro (in the
LCA System Settings menu), or
remotely.
This switch overrides other.
Pressing this switch during a
measurement, will invalidate your
results.
4 Optical Output Warning: Laser Radiation can
damage your eyesight!
Refer to “Laser Safety” on page 12
for safety instructions.
This is the output of the optical
transmitter of the lightwave
component analyzer.
5 Optical Input 1
(low power)
Caution: Do not apply more than
+7 dBm (maximum safe average
input power).
This input is the standard optical
input to the optical test set for
optical powers up to +4 dBm.
6 Optical Input 2
(high power)
Caution: Do not apply more than
+17dBm (maximum safe average
input power).
This is the input to use if your
peak optical input power is
between +4dBm and +14dBm.
This input has reduced sensitivity.
7 Port B This is the RF output from the
receiver of the optical test set.

Introduction
18 Keysight N4373D Lightwave Component Analyzer, User’s Guide
8 Function keys Used to control the Lightwave
Component Analyzer.
Press the [Macro/Local] Utility
button on the network analyzer to
display the LCA function keys.
•: Setup an LCA
Measurement
•: Perform a single sweep
measurement with the current
measurement setup
•: Perform continuous
sweep measurements with the
current measurement setup
•: Start the optical power
meter
•: Start the LCA server (if
not already running)
9 Network analyzer
Port 2
This is an S parameter
measurement port of the network
analyzer.
Depending on the S parameters of
the measurement this can be
either an RF input or an RF
output.
10 Network analyzer
Port 1
This is an S parameter
measurement port of the network
analyzer.
Depending on the S parameters of
the measurement this can be
either an RF input or an RF
output.