MICROWAVE PHOTONIC FILTER INSERTING AN ELECTRO-ABSORPTION MODULATOR IN A VARIABLE POLARIZATION BEAM SPLITTER-BASED SAGNAC FIBER LOOP

摘要

A coherence-free microwave photonic filter configuration is presented. It is designed by using a Sagnac interferometer consisting of a variable polarization beam splitter and an electro-absorption modulator. The variable polarization beam splitter generates π/2 phase difference between the clockwise and counterclockwise waves propagating inside the fiber loop interferometer. Measured results match closely with the theoretical analysis and demonstrate a robust notch filter response.