Push-pull poled polymer Mach-Zehnder modulators with a single microstrip line electrode

A push-pull structure has been realized for integrated Mach-Zehnder modulators based on a thermoset electrooptic polymer. The two modulator waveguide arms were poled in the opposite directions and covered by a single microstrip line electrode. This device structure can reduce the half-wave voltage by 50% without compromising wide-band frequency response. Efficient poling was achieved by using a compatible cladding material to lower the poling voltage, and by using a top cover piece and an inert gas to suppress air breakdown between the poling electrodes. Our fabricated devices exhibited the predicted 50% half-wave voltage reduction compared with non-push-pull devices fabricated on the same chip.