OPTICAL TRANSMISSION SYSTEMS INCLUDING OPTICAL COMPONENTS AND OPTICAL FILTERS AND METHODS OF USE THEREIN

摘要

Optical transmission systems of the invention include at least one double pass Mach-Zehnder filter (40), comprising a first optical coupling section (421) coupling at least one input/output port (46) to a first end of two or more optical paths, or Mach-Zehnder legs (44), having different effective lengths. A second optical coupling section (422) couples at least one output/input port (48) to the second end of the optical paths (44). The double pass Mach-Zehnder filter (40) is configured such that the output from at least one of the output/input ports is coupled back into one of the output/input ports to pass through the Mach-Zehnder interferometer a second time.