How to Set the Wavelength Tunable Lasers
Agilent 8163A Lightwave Multimeter, Agilent 8164A Lightwave Measurement System, & Agilent 8166A Lightwave
Multichannel System, Fourth Edition
111
How to Set the Wavelength Directly
You can set a constant wavelength.
To set the wavelength to 1545.500 nm:
1 Move to the Tunable Laser channel.
2 Move to the wavelength parameter, [λ], and press Enter.
3 Enter 1545.500 and press Enter.
How to Set a Relative Wavelength
You use a relative wavelength for heterodyning, for example, when you are
measuring the linewidth of DFB (distributed feedback) lasers.
The output wavelength, λ, is set from the base wavelength, λ
0
, and the frequency
offset, df. The formula for calculating the output wavelength is:
where c is the speed of light in a vacuum (2.998×10
8
ms
−1
).
To set a frequency offset of 1.000 THz from a base wavelength of 1545 nm:
1 Move to the Tunable Laser channel and press [Details].
2 Press [Menu]. The menu appears.
3 Move to <Wavelength Mode> in the menu and press Enter. A menu appears.
4 Move to <Offset>, by using the cursor key, press Enter, and press Close. You
see the screen in Figure 71.
λ
cλ
0
λ
0
df c+
--------------------=
Figure 71 Setting a Relative Wavelength