MSc. Optical communciations; systems engineering. OTDR lab
OBJECTIVE: To measure the attenuation in a number of links or devices
EQUIPMENT: 1. OTDR
2. Patch leads
3. Fibre
4. OTDR software
PROCEDURE and RESULTS:
A. Analyse the following traces
1. 1310_1550_50km_fiber1.trc
i. Compare the system loss at 1310 versus 1550nm and comment on.
2. 1310_1550_1625_macrobend.trc
i. Identify the position (km) of the macrobend and the loss due to it at different wavelengths. Comment on why the loss is different.
3. 7500E_1550_1625.trc
i. What is the apparent increase in power after item 6.
4. Gainer_AB.trc
i. Between items 2 and 3 discuss what is happening.
5. pon_spl1x8_1x4.trc
i. What are the two sudden drops in optical power. Measure them and use the results to support your answer.
6. Bidir000001_1310.bdr
i. Comment on Item 2. How are the different results for this splice reconciled. Ie. Measurements taken from different ends of the fibre give different losses.
B. Why does “ANSI/TIA/EIA-455-8-2000 Measurement of Splice or Connector Loss and Reflectance using an OTDR” recommend measuring splice loss from both directions. See attached document for details
C. Using a trace taken in class identify the following items
1. splice
2. connector
3. fibre length
4. fibre end
5. mechanical splice
D. Discuss what a fibre dead zone is and how it can be worked around.
E. Discuss what a fibre echo is and how it occurs. Use example trace from class.
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