Reference
This section describes available
fi
lter selections, clock recovery enabling
procedures, and optical bandwidths.
Wavelength, Filter, and Bandwidth Selection
See Tables 1 and 3 for available wavelength,
fi
lter, and bandwidth information.
(See Table 1 on page 2.) (See Table 3 on page 3.)
To select the optical wavelength, open the Vertical Setups menu. (See Figure 4
on page 13.)
Select the channel in the Waveform section of the menu. Then select the
wavelength of the signal to measure from the Setup Wavelength drop down box.
Use the Signal Conditioning boxes to select the
fi
lter and bandwidth appropriate
for your optical standard.
For more information, see the Online Help for your main instrument.
Clock Recovery
The 80C12B module comes standard with buffered electrical signal outputs.
Connect the buffered outputs to a CR175A or CR286A Clock Recovery module
to obtain a clock recovery signal. Refer to the CR175A or CR286A module user
documentation for triggering information.
When connecting cables to the BUFFERED outputs, make sure to torque the
connector to the proper value of 56 N/c (5 in-lb) ±2.8 N/c (0.25 in-lb)
Make sure to torque the SMA connector to the proper value when connecting
cables to the BUFFERED outputs:
56 N•c (5 in-lb) ±2.8 N•c (0.25 in-lb)
Electrical versus Optical Bandwidth
Electrical bandwidth is de
fi
ned as the frequency at which the power out is one half
the power out at a frequency near DC. In the voltage domain the power dissipated
into a resistive load (such as a 50
Ω
termination of a sampler) is the V
RMS
2
/R
where V
RMS
is the RMS of the voltage swing seen at the resistive load, and R is
the resistance value. The frequency dependent response of a system is typically
described using a logarithmic decibel scale. A value expressed in terms of a
decibel relative to a reference is de
fi
ned as:
80C12B Optical Sampling Module User Manual
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