Optical amplifiers – Test methods – Part 10-5: Multichannel parameters – Distributed Raman amplifier gain and noise figure
|Publication Date:||1 May 2014|
|ICS Code (Optic amplifiers):||33.180.30|
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.