Coplanar-waveguide-based silicon Mach-Zehnder modulator using a meandering optical waveguide and alternating-side PN junction loading

We demonstrate a silicon Mach-Zehnder modulator with a coplanar waveguide transmission-line electrode structure using a meandering optical waveguide and alternating-side PN junction loading of the electrodes, which helps suppress the signal distortion caused by the parasitic slot-line mode and improves the electro-optic (EO) bandwidth. The silicon MZM exhibits a pi-phase-shift voltage (V-pi) of 4.5 V with an EO 3 dB bandwidth of similar to 20 GHz for a 5 mm long phase shifter. This achieved V pi is among the lowest for silicononly modulators with a bandwidth of more than 20 GHz. (C) 2016 Optical Society of America