HP 8163A Series, User Manual

Page: 93 / 207

93
Using Laser Source Modules
How to Use Laser Source Modules
indicated by Modulation Frequency parameter, [M
OD
F
RQ
]. The
modulated outputis a square wave, with a duty cycle of 50%.
If <O
FF
> is displayed, the laser source outputs an unmodulated
continuous-wave signal.
N OT E If you choose to output both wavelengths of the HP 81554SM Dual
Wavelength Laser Source and to modulate the optical output signal, the
two signals will be 180
°
out of phase with each other.
How to Modulate the Output Signal
This parameter sets the frequency of modulation for a laser source
module. The signal is internally modulated at this frequency if the
Modulation Source parameter, [M
OD
S
RC
], is <O
N
>.
To modulate the optical output at a frequency of 2 kHz:
1 Move to the laser source channel and press the [Details] softkey.
2 Move to the [M
OD
F
RQ
] parameter and press E
NTER
.
3 Enter 2.000 and press E
NTER
.
4 Move to the [M
OD
S
RC
] parameter and press E
NTER
.
5 Move to <I
NTERNAL
>, by using the cursor key, and press E
NTER
.
6 Enable the laser output, by pressing the A
CTIVE
hardkey on the
module’s front panel.