Comparison Study of Multi-Slot Designs in Epsilon-Near-Zero Waveguide-Based Electro-Optical Modulators

We present a systematical comparative research on the modulation performance and optimization of multi-slot waveguide modulator at telecom wavelength 1.55 μm. It is found that existence epsilon-near-zero indium tin oxide slots in modulators can enhance optical confinement, thus yielding high extinction ratio (ER) low insertion loss. Among designed four types slot modulators, single-slot exhibits widest bandwidth 78.75 GHz lowest energy consumption 1.15 pJ/bit, while dual-slot one shows moderate performance. For more-slot designs, tri-slot has advantages maximum figure merit ~106, quadri-slot highest ER 1.38 dB/μm. By integrating silicon waveguide, broad 83 nm from 1479 to 1560 large depth (~18.3 dB). The be further improved different aspects by their geometric parameters. results this work could useful design selection on-chip for communications ultrafast data processing.