Multi-Parameter Optimization of a Shallow Ridge InP Traveling Wave Mach-Zehnder Modulator for Beyond 200 Gb/s Optical Datacom Applications

We present multi-parameter optimization of a shallow ridge InP-based traveling wave Mach-Zehnder modulator (MZM) for ultra-wide modulation bandwidth by velocity and impedance matching and microwave attenuation minimization. Relationship between MZM microwave loss and p-cladding layer doping profile is quantitatively analyzed and incorporated in device optimization. We propose a systematic analysis methodology allowing the full optimization of an InP shallow ridge MZM capable of 200 Gb/s PAM4 operation, compatible with high-volume low-cost manufacturing. Our design is expected to achieve 4.3 V half-wave voltage and 81 GHz 3-dB bandwidth with simplified fabrication process and improved long-term reliability.