Agilent Technologies Agilent 86120B, User Manual

Page: 77 / 268

3-9
Measurements Applications
Measuring Laser Drift
Measuring Laser Drift
In this section, you’ll learn how the Agilent 86120B can be used to monitor
drift (changes to a laser’s wavelength and amplitude over time). Drift is mea-
sured simultaneously for every laser line that is identified at the input. The
Agilent 86120B keeps track of each laser line’s initial, current, minimum, and
maximum values and displays their differences relative to itself. This allows
the Agilent 86120B to be used for laser transmitter evaluation, burn-in, or
development. In addition, you can monitor system performance over time,
temperature, or other condition.
The following display shows power and wavelength drift measured on five
laser lines. The
DRIFT
annotation, item
➀
, tells you that drift measurements
are being performed. The current relative drift values for wavelength and
power are shown in items
➁
and
➂
respectively. Item
➃
indicates the absolute
reference values for the laser line indicated by the cursor . The reference
values are measured before the measurement starts.
You can restart the drift measurement at any time by pressing the RESET soft-
key. All minimum and maximum values are reset to the reference values, and
the Agilent 86120B begins to monitor drift from the current laser line values.
Move the cursor up and down the listing to see the reference wavelength and
power of each laser line.