Two-mode mode multiplexer/demultiplexer in polymer planar waveguide.

We proposed a two-mode multiplexer/demultiplexer (mux/demux) device using an unbalanced Mach-Zehnder interferometer with Y junctions. The proposed device had simulated extinction ratio greater than 30 dB for both mux and demux operations with an excess loss of 0.17 dB. The device was fabricated using polymer materials and characterized via a tunable laser source over the wavelength of 1545-1555 nm. The experimental performance of the device closely agreed with the theoretical prediction. The proposed device is easy to fabricate and will have applications in future multimode transmission systems for further extending fiber transmission capacity.