Proceedings Article | 11 March 2024
KEYWORDS: Modulators, Design, Modulation, Electrooptic modulators, Plasmonics, Oxides, Signal attenuation, Mach Zehnder interferometers, Refractive index, Phase modulation
This study introduces an innovative indium tin oxide (ITO) plasmon-based asymmetric Mach-Zehnder Interferometer (MZI) modulator, designed to tackle prevailing issues in photonic modulators. Emphasizing the modulator’s attributes, we offer low bias voltage, compactness, sufficient extinction ratio (ER), low insertion loss (IL), and low electrical resistance, paving the way for operational speeds up to multiple GHz. We meticulously examined material properties and modulator design to strike an optimized balance between ER and IL, adhering to the constraints of minor phase shifts. A 4.7 μm-long ITO-plasmon-based asymmetric MZI modulator was devised, incorporating a phase shift of 0.33π, an ER of 3 dB, an IL of 2.9 dB, and a speed of 108 GHz under the bias of ±3.5 V. The device length is judiciously selected considering high transmission difference, high ER, and low IL. Our asymmetric MZI modulator (41:59) results in 0.4 dB lower IL in comparison to the symmetric MZI modulator. In terms of modulation depth, an amplified oxide thickness can curtail the device’s capacitance, thereby augmenting the RC-limited device bandwidth. Concurrently, we propose a design protocol to attain tailored metrics such as modulation depth, speed, and losses that broaden the selection of active materials for engineering modulators with functionality-based performance. Notably, the modulator showcases remarkable switching speeds up to 100 GHz, a notably low energy consumption of 380 fJ/bit, and is adaptable to a multitude of material frameworks. This work marks a significant stride in the field of photonic modulators, opening new avenues for compact, high-performance, and energy-efficient modulating devices.
