Tektronix OI1125, Instruction Manual

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Performance Verification
38
OI1125 E/O Transmitter Instruction Manual
Compensate the Oscilloscope.
The optical sampling heads are susceptible to
temperature fluctuations. Therefore, do the following prior to taking measure-
ments:
1. Disconnect the optical cable from the input to the oscilloscope.
2. Execute a compensation of the optical sampling head as soon as the
sampling head has reached operation equilibrium (that is, after a 30 minute
warm-up). Compensation for the entire system or for an individual optical
module can be initiated from the Utilities menu Compensation command.
For more information, see Optimizing Measurement Accuracy in the main
instrument user manual.
Oscilloscope. Set the TDS8000 Vertical settings as follows:
NOTE
. Due to differences in oscilloscope firmware, your setup steps may differ
slightly.
3. From the toolbar, select Setup
→
Vertical.
4. Click the Optical>> button.
5. Set the Signal Conditioning mode:
a. In the Wavelength field, select 1550 from the drop-down menu.
b. In the Filter field, select OC-48 from the drop-down menu.
NOTE . You must change the Filter field setting when you take measurements at
other data rates. See Table 12.
A filter is not used for the 12.50 Gb/s data rate. Instead, set the Filter field to
None, and set the bandwidth to 12.50 GHz.
Table 12: Signal conditioning mode settings
Data rate,
Gb/s Wavelength
field setting Filter field
setting Bandwidth
setting, GHz
2.488320 1550 OC-48 ––––––––
9.953280 1550 OC-192 ––––––––
12.500000 1550 None 12.50
6. Select the Horz tab to set the horizontal parameters.