Agilent Technologies 86140B Series, User Manual

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6-9
Maintenance
Cleaning Connections for Accurate Measurements
• 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
connectors. Often as much as 90 dB isolation is needed.
Figure 6-2. Basic components of a connector.
Over the last few years, the FC/PC style connector has emerged as the most
popular connector for fiber-optic applications. While not the highest perform-
ing connector, it represents a good compromise between performance, reli-
ability, and cost. If properly maintained and cleaned, this connector can
withstand many repeated connections.
However, many instrument specifications require tighter tolerances than most
connectors, including the FC/PC style, can deliver. These instruments cannot
tolerate connectors with the large non-concentricities of the fiber common
with ceramic style ferrules. When tighter alignment is required, Agilent
Technologies instruments typically use a connector such as the Diamond
HMS-10, which has concentric tolerances within a few tenths of a micron. Agi-
lent Technologies then uses a special universal adapter, which allows other
cable types to mate with this precision connector. See
Figure 6-3 .