PCM aided PICs: a Crucial Migration Towards Cutting-Edge Signal Processing

Advanced signal processing is paramount in different sectors, including wireless communications, neural networks, artificial intelligence, quantum computing, medical diagnosis, internet of things, etc. With its rapid growth, silicon photonic integrated circuit (PIC) based signal processors are established to be a strong competitor to their electronic counterparts, owing to various advantages like small footprint, low energy consumption, immunity to electromagnetic interference, high speed operation, CMOS compatibility, etc. However, traditional means of realizing programmability, such as thermo-optic and carrier dispersion often suffer from large footprints due to small modulation in refractive index. Further, the volatile nature of such a programming mechanism requires a continuous power supply. In this context, a new generation of low-loss, large index contrast, non-volatile phase change materials (PCMs) are showing great promise towards upscaling the silicon photonic signal processing units. Here, a compact resonator cavity-based signal processing unit is proposed through advantageous integration of a hybrid plasmonic mode in the silicon photonic domain and low-loss PCM. Excellent switching performance with extinction ratio > 30 dB and low energy consumption of 7.6 nJ, highlighting its promise towards different sectors such as telecommunications, neural networks, etc.