A four-port multimode fiber FBT coupler has 50 W optical power launched into port 1. The measured output power at ports 2,3 and 4 are 0.003, 23.0 and 24.5 W respectively. Determine the excess loss.

A four-port multimode fiber FBT coupler has 50 W optical power launch

1.	A four-port multimode fiber FBT coupler has 50 W optical power launched into port 1. The measured output power at ports 2,3 and 4 are 0.003, 23.0 and 24.5 W respectively. Determine the excess loss.
A.	0.22 dB
B.	0.33 dB
C.	0.45 dB
D.	0.12 dB
Answer» B. 0.33 dB