Optical add-drop multiplexer

Abstract

An optical add-drop multiplexer is disclosed. The optical add-drop multiplexer includes a first loop for dropping a first polarized light signal having a corresponding wavelength from a multiplexed downstream optical signal and adding a second polarized light signal having a corresponding wavelength to a multiplexed upstream optical signal and a second loop for adding a first polarized light signal having a corresponding wavelength to the downstream optical signal input from the first loop. An upstream optical signal is output in which a second polarized light signal having a corresponding wavelength is dropped from towards the first loop and the multiplezer also includes a Bragg grating placed between the first and second loops for reflecting the first and second polarized light signals having the corresponding wavelengths respectively towards the first and second loops.

Dependencies are inferred from the claim text.