Patent ID: 6556742
Filing Date: 2003-04-29
Classification: G02B,H04J

Abstract:
An optical wavelength division multiplexed system comprising:a splitter splitting input light into a first path and a second path, the first path including even-numbered channels and the second path including odd-numbered channels, the first path comprising a first tunable optical filter and said second path comprising a second tunable optical filter, said first tunable optical filter dropping at least one of the even-numbered channels into a first dropped path comprising a third tunable optical filter and said second tunable optical filter dropping at least one of the odd-numbered channels into a second dropped path comprising a fourth tunable optical filter, wherein the first tunable optical filter and the third tunable optical filter are coupled directly in cascade with each other and have the same filtering characteristics as each other, and wherein the second tunable optical filter and the fourth tunable optical filter are coupled directly in cascade with each other and have the same filtering characteristics as each other.