was about 14 dB at 0.124 T and it increased as the magnetic
field increased from 0 to 0.124 T. When the magnetic field was
larger than 0.124 T, the isolation decreased due to the fact of
polarization state started returning to the earlier state. The small
deviation of the magnetic field (0.124 T) for themaximumisolation
of 14 dB from that (0.119 T) for the Faraday rotation angle
of 45 is due to the linear birefringence variations induced by
environmental noise by using the reflection mirror. This error
can be decreased further by using a total reflection mirror such
as fiber Bragg grating at 660 nm [11], [29].
The mismatch between experimental results and lines obtained
from the theory (theMalus’ law) in Figs. 6 and 7 is due to
the linear birefringence of the optical fiber induced by windings