Looped optical network with ASE light recirculation and link and network survivability control system

摘要

A looped WDM optical network comprises an optical loop with optical amplifiers ( 12,16 ) between the sections of the loop ( 11 ) and with ASE recirculation in the loop. At a point of the loop a laser beam is injected and allowed to circulate in the loop with the laser beam being centered around a lambda_LINK wavelength where it is desired that a lasing peak be generated. This supplies high network strength in terms of section loss variations and greatly improves the OSNR of the WDM signal. High network survivability is also achievable.