Hi all,
These are different useful regarding Optical amplifiers links which i notice especially for YDFA amplifiers.
http://www.optilab.com/products/category/ydfa/ytterbium-doped_fiber_amplifier_rackmount/
http://www.gehtinternational.com/products/telcoms-remote-sensing/amplifiers.php
http://www.amonics.com/amonics/php/en/products_details.php?id=124
http://www.acalbfi.com/uk/Fibre-optic-components/Actives/Fibre-optic-amplifiers/p/YDFA–Ytterbium-doped-fibre-amplifier–series-1m/0000005RLQ
http://www.iasj.net/iasj?func=fulltext&aId=51984
Hope you will find some useful knowledge and achnowledge us.