A monolithic bipolar CMOS electronic–plasmonic high-speed transmitter

To address the challenge of increasing data rates, next-generation optical communication networks will require the co-integration of electronics and photonics. Heterogeneous integration of these technologies has shown promise, but will eventually become bandwidth-limited. Faster monolithic approaches will therefore be needed, but monolithic approaches using complementary metal–oxide–semiconductor (CMOS) electronics and silicon photonics are typically limited by their underlying electronic or photonic technologies. Here, we report a monolithically integrated electro-optical transmitter that can achieve symbol rates beyond 100 GBd. Our approach combines advanced bipolar CMOS with silicon plasmonics, and addresses key challenges in monolithic integration through co-design of the electronic and plasmonic layers, including thermal design, packaging and a nonlinear organic electro-optic material. To illustrate the potential of our technology, we develop two modulator concepts—an ultra-compact plasmonic modulator and a silicon-plasmonic modulator with photonic routing—both directly processed onto the bipolar CMOS electronics.