Agilent Technologies 86120C, User Manual

Page: 36 / 294

2-8
Making Measurements
Measuring Wavelength and Power
The following equation shows how individual p owers 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
i
is the peak power of an individual laser line. Power units are in Watts (linear).
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
THz or cm
- 1
is chosen. See “To change the units of measure” on
page 2- 12 .
The grap hical disp lay uses the start and stop wavelength values to p lot
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.
P
total
P
i
i 1 =
n
∑
=