Silicon-Based Multimode Interference (MMI) Switch Utilizing Carrier Injection Based Electro-Optic Effect

Silicon photonics is swiftly becoming a key technology with a wide range of applications in communication systems, Li-DAR, sensing optical integrated circuits [1]–[5]. With ongoing advancement in the fabrication processes and techniques for semiconductor and photonic devices, the demand for silicon photonic chips is consistently on the rise. Silicon photonic devices offer inherent advantages such as low power consumption, low latency, high bandwidth and ease of integration with CMOS devices are therefore gaining prominence. A critical application within this field is optical switching []. In silicon photonic chips, switching functions are predominantly executed by micro-ring resonators or Mach-Zehnder interferometers (MZIs) [6], [7]. While ring resonators are compact and energy-efficient, their sensitivity to input wavelength and coupling gap poses significant challenges for realization. Conversely, MZIs exhibit greater tolerance to wavelength variations but suffer from larger cross-sections and associated insertion losses, making them less preferable. These limitations of ring resonators and MZIs have prompted researchers to explore alternative solutions. Multimode interference (MMI) splitter-based switches have emerged as ideal candidates for switching applications due to their compact size and reduced fabrication complexity [8], [9].