Figure 2:
Variation of the gain at 1310, 1470, 1530, 1600, 1650 nm with fiber length. Pump power, input signal power are 200 mW/200 mW,
−
30 dB m, respectively. The optimal concentration P
r
3
+
=
1
.
9
×
1
0
2
4
, T
m
3
+
=
3
.
9
×
1
0
2
4
, E
r
3
+
=
1
.
2
×
1
0
2
4
ions/
m
3
, and energy transfer coefficient
W
e
t
6
-
3
=
6
3
×
1
0
−
2
0
,
W
e
t
6
-
1
0
=
2
0
0
×
1
0
−
2
2
.
