A telecom provider is troubleshooting a 60km long-haul single-mode link. The link passes perfectly at 1310nm but shows 8 dB of excess loss at 1550nm. What is the most likely physical cause?
Answers
AThe connectors are dirty
BThe fiber is contaminated with water (water peak attenuation)
C1310nm is inherently better at traveling long distances than 1550nm
DThere is a severe macrobend somewhere in the cable run
Correct answer: D — There is a severe macrobend somewhere in the cable run
Macrobends (sharp physical bends in the fiber) cause significantly higher loss at longer wavelengths like 1550nm because the light mode field diameter is larger and more easily escapes the core when bent.
MIFOTRA exam practicealigned to TIA-568.3-D / ITU-T G.652·4 marks·Hard