Design of Hybrid Plasmonic Multi-Quantum-Well Electro-Reflective Modulators Towards amp;100 fJ/bit Photonic Links

摘要

Realization of on-board and inter-chip optical interconnects requires a photonic data link with power consumption well below their electrical counterparts (i.e., amp;amp;1 pJ/bit). Currently, directly modulating 850 nm vertical cavity surface emitting lasers at amp;50 Gb/s requires 2–4 pJ/bit/channel. External reverse-biased modulators could drastically reduce this power consumption. Here we design ultralow power GaAs/AlGaAs multi quantum well electro-reflective modulators operating at 1 V for facile integration with polymer “optical bridges”, utilizing coupled quantum confined Stark effect between adjacent quantum wells and optical coupling to hybrid surface plasmon-slab modes for significantly enhanced extinction ratio and spectral bandwidth. Distinctive from conventional electro-optical or electro-absorption modulators, this new design synergistically leverages ultra-large changes in both refractive index (Δn～0.05) and absorption coefficient (Δα～10amp;supamp;4amp;/supamp; cmamp;supamp;?1amp;/supamp;), achieving 35-50 dB extinction ratio at 1 V reverse bias with a low insertion loss of 1–3 dB, an incident angle tolerance of ～5°, and a spectral bandwidth of 7–10 nm. The modulator power consumption is ～1.9 fJ/bit without the need of thermal tuning, and the RC-limited bandwidth well exceeds 100 GHz. This new modulator enables high bandwidth and ultralow power optical interconnect networks at amp;100 Gb/s/channel and amp;100 fJ/bit/channel compatible with ever-scaling CMOS technologies.