Emerging Modulator Technologies in Silicon Photonics

The evolution of high-speed optical modulators in silicon photonics is crucial for advancing optical communication networks amid growing data demands and expanding data centers. This review covers the latest developments in modulator technologies, focusing on mechanisms like the plasma dispersion effect, Pockels effect, Franz-Keldysh effect, quantum confined Stark effect (QCSE), slow light effect, interband transitions, and phase transitions. Key modulator types, including Mach-Zehnder Modulators (MZMs), Ring Modulators, Ring-Assisted Mach-Zehnder Modulators (RAMZMs), and Electro-Absorption Modulators (EAMs), are explored for their distinct advantages in high-speed optical applications. It explores physical principles, material platforms, and integration techniques vital for efficient manipulation of light's properties in high-speed data transmission. Emphasis is placed on silicon photonics for its scalability, cost-effectiveness, and CMOS compatibility. The review also discusses hybrid platforms, slow light-based modulators, and emerging technologies to enhance bandwidth, reduce power consumption, and improve integration. Challenges such as material compatibility, fabrication complexity, and performance optimization are addressed, aiming to guide future research on scalable modulators for next-generation optical networks.