Keysight Technologies 86120B, User Manual

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Performance Tests
Test 4. Optical Input Return Loss
Test 4. Optical Input Return Loss
Description Input return loss is verified using the following devices:
• 8153A Lightwave Multimeter
• 81553SM 1550 nm Fabry-Perot laser, SM 9/125
μ
m Source Module
• 81534A Return Loss Model
Procedure: Standard instruments (flat contacting connectors)
1 Turn the source module’s output off.
2 Connect a single-mode patchcord between the source module’s optical output and the
return-loss module’s INPUT SOURCE connector.
3 Set the return-loss module’s wavelength to 1550 nm, and select an average time of 1
second.
4 Locate an HMS-10/HRL to FC/PC patchcord. Connect the HMS-10/HRL end of the
patchcord to the return-loss module’s OUTPUT connector. Terminate the other end
of the cable.
5 Zero the return-loss module.
6 Turn on the source module.
7 Remove the termination from the cable, and leave the cable’s free end uncovered.
8 The return-loss module measures the reflection reference (14.6 dB return loss of the
patchcord’s FC/PC connector in air).
9 Make a low-reflection termination in the HMS-10/HRL to FC/PC patchcord. Do this
by wrapping the cable 6 times around a 5 mm diameter mandrel.
10 The return-loss module measures the termination parameter.
11 Connect the HMS-10/HRL to FC/PC patchcord to the Keysight 86120B’s front panel
OPTICAL INPUT connector.
12 The lightwave multimeter measures the return loss. Compare this measurement with
the specification listed in
Chapter 7, “Specifications and Regulatory Information” .