92 Keysight N777-C Series Tunable Laser Family User’s Guide
5 N777-C Instrument’s Front Panel Display
How to Set the Wavelength Unit?
Pressing the unit button allows you to switch either nm or THz as the units
in which power is displayed.
What are the Wavelength Unit?
The SI unit of wavelength measurement is meter usually denoted as m.
How to Set Power?
How to change the power
You can set the power value by directly clicking on the Power button.
For details, see Changing Wavelength, Power and Units on page 89.
How to Set the Power Unit
Pressing the unit button allows you to switch either mW or dBm as the
units in which power is displayed.
What are the Power Units?
Watts (W) are the SI unit for power measurement.
You can also measure power in dBm. Values displayed in these units are
derived from measurement in Watts.
By selecting dBm, the following calculation is made:
Where,
P
dBm
is the power value displayed in dBm, and
P
input
is the input signal level in Watts.
Power, in units of dBm, is measured relative to 1 mW, it is an absolute
power measurement.