Agilent Technologies 86120C User Manual page 36

Making Measurements
Measuring Wavelength and Power
The following equation shows how individual powers of laser lines are
summed together to obtain the total power value:
where,
n is the number of laser lines included in the measurement.
P is the peak power of an individual laser line. Power units are in Watts (linear).
i
To display average wavelength and total power
• Press the Avg WL key.
Limiting the wavelength measurement range
The wavelength range of measurement can be limited with the wave-
length limit function. Both start and stop wavelengths can be chosen.
The units of wavelength start and stop are the same as the currently
selected wavelength units. If wavelength units are later changed, the
start and stop wavelength units will change accordingly. Note that a
start wavelength limit in nm will become a stop wavelength limit if
- 1
THz or cm is chosen. See
page 2- 12.
The graphical display uses the start and stop wavelength values to plot
the power spectrum, whether the wavelength limit function is on or
off.
Preset turns wavelength limiting on. Only responses that are within the
boundaries of the chosen start and stop wavelength limits are mea-
sured. This includes Peak WL, List by WL, and List by Power modes.
To limit the wavelength range
1 Press the Setup key.
2 Press the WL LIM softkey.
3 Press the STARTWL softkey to adjust the start wavelength value.
4 Press the STOP WL softkey to adjust the stop wavelength value.
2-8
n
P = P
∑
total i
i = 1
"To change the units of measure" on