
38 Optical Fiber Communication Systems with MATLAB
®
and Simulink
®
Models
2.5.1 Definitions of ESI Parameters
The
ESI
description
can
be
used
to
design
SMF
with
graded
index,
W-
or
segmented
core
proles
(under
some
limitations)
as
illustrated
in
Figure
2.8.
These
non
step-index
proles
can
be
described
by
ESI
parameters
denoted
by
V
e
= the effective or equivalent V param-
eter;
a
e
= the ESI core radius; λ
ec
= the ESI cutoff wavelength; Δ
e
= the equivalent relative
index
d
ifference.
These
p
arameters
a
re
r
elated
t
o
t
he
rst
t
wo
m
oments
M
0
,M
1
dened as
M n r n a r dr
n
n
= −
∞
∫
2 2
0
( ) ( ) . (2.55)
For n = 1, 2, the effective V
e
parameter and effec ...