CEI EN 61290-10-5

Scope and object

This part of IEC 61290 applies to distributed Raman amplifiers
(DRAs). DRAs are based on the process whereby Raman pump power is
introduced into the transmission fibre, leading to signal
amplification within the transmission fibre through stimulated
Raman scattering. A detailed overview of the technology and
applications of DRAs can be found in IEC TR 61292-6.

 A fundamental difference between these amplifiers and
discrete amplifiers, such as EDFAs, is that the latter can be
described using a black box approach with well-defined input and
output ports. On the other hand, a DRA is basically a pump module,
with the actual amplification process taking place along the
transmission fibre. This difference means that standard methods
described in other parts of IEC 61290 for measuring amplifier
parameters, such as gain and noise figure, cannot be applied
without modification.

The object of this standard is to establish uniform requirements
for accurate and reliable measurements, using an optical spectrum
analyser (OSA), of the following DRA parameters:

a) channel on-off gain;

b) pump unit insertion loss;

c) channel net gain;

d) channel signal-spontaneous noise figure. The measurement
method is largely based on the interpolated source subtraction
(ISS) method using an optical spectrum analyser, as described and
elaborated in IEC 61290-10-4, with relevant modifications relating
to a DRA.

All numerical values followed by (‡) are suggested values for
which the measurement is assured. Other values may be acceptable
but should be verified.

NOTE General aspects of noise figure test methods are reported
in IEC 61290-3.