الفهرس 
Properties Of Rare-Earth Ions In Silica Glass
Amplifier EfficiencyOnly 14 pages are availabe for public view
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Abstract
Summary
In order to extend the span length of the long haul repeater1ess
optical fiber link.s, optical amplifiers are used. EDFA has the
advantage of high saturation power, low noise, Low crosstalk.,
polarization insensitivity, and broad spectral band width.
In this wor1c optimum design for a preamplifier configuration
suitable for submarine link.s is considered. The criteria of optimization
is that active components are placed on land. The competitive
configurations are the local pumping at 0.98 ~m with its superior noise
characteristics or backward remote pumping at 1.48 with an extra fiber
length gain .
In this wor1c we have shown the advantages of the second
system over the first with budget improvement factor ~B that can
reach 9.4 dB. In this improvement a bonus of Raman gain has been
noticed. After summarizing the concepts of the physical background
needed a theoretical model for the system has been derived. At the
same time, experimental wor1c on the system was done. The
philosophy of the experimental wor1c is based on experimental aided
design. where first individual components have been check.ed
experimentally. Particularly single fiber attenuation and EDFA gain has
been measured separately for different lengths. Then by an
optimization technique has been performed to minimize the overall
noise factor of the system which can contain more than one EDFA
spaced by standard fiber sections under the constrain of fixed total
net gain for the system. This design is then realized practically step by
step starting backwards and measuring the parameters of the gain
and noise factor in each step.
It was found that one EDFA with one long span single fiber
gives the best budget improvement {Ll.B). The last system has bean
studied in detail theoretically, and a numerical calculation has been
performed on the full nonlinear coupled equations for the P P• P •. P ASE ,
pump power, signal power, and amplified spontaneous emission
power, together with the nonlinear Raman amplifiCation equations.
The parameters such as A.. , A., , P P• P. t-..wn. z-”””’. and r o
are varied to see how the signal to noise ratio and budget