Nonvolatile electrically reconfigurable integrated photonic switch
Reconfigurability of photonic integrated circuits (PICs) has become increasingly important due to the growing demands for electronic photonic systems on a chip driven by emerging applications, including neuromorphic computing, quantum information, and microwave photonics. Success in these fields usually requires highly scalable photonic switching units as essential building blocks. Current photonic switches, however, mainly rely on materials with weak, volatile thermo optic or electro optic modulation effects, resulting in a large footprint and high energy consumption. As a promising alternative, chalcogenide phase change materials (PCMs) exhibit strong modulation in a static, self holding fashion. Here, we demonstrate nonvolatile electrically reconfigurable photonic switches using PCM clad silicon waveguides and microring resonators that are intrinsically compact and energy efficient. With phase transitions actuated by in situ silicon PIN heaters, near zero additional loss and reversible switching with high endurance are obtained in a complementary metal oxide semiconductor (CMOS) compatible process. Our work can potentially enable very large scale general purpose programmable integrated photonic processors.