
348 Optical Fiber Communication Systems with MATLAB
®
and Simulink
®
Models
where
α
is
the
intensity
coupling
ratio
of
the
coupler.
Thus,
the
eld
components
at
ports
1
and
2
can
be
derived
by
combining
the
X_and_YX_and_Y components
from
(8.51)
and
(8.52),
a
nd
t
he
t
otal
po
wer
a
t
po
rts
1 a
nd
2 a
re
g
iven
a
s
P P P P P K t
P P
R s L s L p IF m t p c
R s
1
2
1 2 1= − + + − + + −
=
( ) ) ( ) sin( )
( )
α α α α ω φ φ φ
α
++ − + − + + − +
=
P P P K t
K K K
L s L p IF m t p e
p sX
( ) ( ) sin( )
( )
1 2 1α α α ω φ φ φ π
with
LLX sY LY sX LX sY LY L s
p
sX LY L s
K K K K K K
K K
+ + −
=
−
−
2
1
cos( )
tan
sin( )
δ δ
φ
δ δ
KK K K K
sX LX sY LY L s
+ −
cos( )δ δ
(8.53)
where
ω
IF
is the intermedi ...