A wide-band guided-wave periodic multi/demultiplexer with a ring resonator for optical FDM transmission systems

A wide-band guided-wave periodic multi/demultiplexer with a ring resonator for optical frequency-division-multiplexing (FDM) transmission systems is demonstrated. This periodic multi/demultiplexer consists of a Mach-Zehnder interferometer and ring resonator. It has a flat wide bandwidth and sharp cutoff regions. The authors describe theoretical analysis, design method, and experimental results of the multi/demultiplexer. The fabricated periodic multi/demultiplexer with a ring resonator has 5-GHz channel frequency separation at the 1.55- mu m wavelength region. Measured average loss was 4.8-dB and the average crosstalk was -13.2 dB. At 0.5-dB loss up from the minimum loss level, a width of 4.0 GHz was measured. This '0.5-dB bandwidth' is 1.8 times wider than that of the conventional Mach-Zehnder type periodic multi/demultiplexer.<
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