Agilent Technologies Agilent 86120C Ventilation Hood User Manual


 
2-13
Making Measurements
Changing the Units and Measurement Rate
4 Press WL and select one of the following units. Then, press RETURN to
complete your selection:
NM for nanometers
THZ for Tera Hertz
CM
–1
for wave number
5 Press POWER and select one of the following units:
DBM for decibels relative to a milliwatt
MW for milliwatts
UW for microwatts
Measurement rate
Under normal operation, the Agilent 86120C makes a measurement
and displays the results about once every second. It is in this normal
update mode that maximum accuracy and wavelength resolution are
achieved. However, should a faster update be desired, for example
when real-time feedback is required to tune a laser to its designated
channel, the Agilent 86120C can be set to update approximately two
times per second. This reduces both wavelength resolution and accu-
racy but can be beneficial in some applications.
The instrument resolution in NORMAL update mode is 7 GHz (0.06 nm
at 1550 nm). This resolution is useful when measuring closely spaced
laser lines carrying data at up to 5 Gb/s rates.
The instrument resolution in FA ST update mode is 14 GHz (0.12 nm at
1550 nm). This resolution is useful when measuring laser lines carry-
ing data at up to 10 Gb/s rates.
NOTE
When measuring laser lines carrying data at 10 Gb/s in NORMAL update mode,
the instrument resolution is less than the modulation bandwidth of the laser lines.
In this case, the displayed power of the laser lines will be less than the actual
power by approximately 1 dB. This power offset can be calculated by comparing
the displayed power to that measured by a power meter. Then, the power offset
can be entered, by pressing Setup, MORE, CAL, PWR OFS, to display the correct
power.