Cleaning Connections For Accurate Measurements - Agilent Technologies 86038A User Manual

Troubleshooting and Upgrades
Choosing the Right Connector
272
Cleaning Connections for
Accurate Measurements
Today, advances in measurement capabilities make connectors and
connection techniques more important than ever. Damage to the
connectors on calibration and verification devices, test ports, cables, and
other devices can degrade measurement accuracy and damage
instruments. Replacing a damaged connector can cost thousands of
dollars, not to mention lost time! This expense can be avoided by
observing the simple precautions presented in this book. This book also
contains a brief list of tips for caring for electrical connectors.
A critical but often overlooked factor in making a good lightwave
measurement is the selection of the fiber-optic connector. The differences
in connector types are mainly in the mechanical assembly that holds the
ferrule in position against another identical ferrule. Connectors also vary in
the polish, curve, and concentricity of the core within the cladding. Mating
one style of cable to another requires an adapter. Agilent Technologies
offers adapters for most instruments to allow testing with many different
cables. Figure 19 on page 273
connectors.
The system tolerance for reflection and insertion loss must be known
when selecting a connector from the wide variety of currently available
connectors. Some items to consider when selecting a connector are:
• How much insertion loss can be allowed?
• Will the connector need to make multiple connections? Some connectors are
better than others, and some are very poor for making repeated connections.
• What is the reflection tolerance? Can the system take reflection degradation?
• Is an instrument-grade connector with a precision core alignment required?
• Is repeatability tolerance for reflection and loss important? Do your specifica-
tions take repeatability uncertainty into account?
• Will a connector degrade the return loss too much, or will a fusion splice be re-
quired? For example, many DFB lasers cannot operate with reflections from con-
nectors. Often as much as 90 dB isolation is needed.

Cleaning Connections for Accurate Measurements

shows the basic components of a typical
Agilent 86038A Optical Dispersion Analyzer, Third Edition