Siliconphotonics

Silicon photonics is the field that uses silicon as a platform for integrated optical circuits, combining photonic components with electronic circuits on a common silicon substrate. Relying on CMOS-compatible fabrication, it enables high-bandwidth optical interconnects and signal processing on a chip, with the potential for low cost, small form factors, and scalable production.

Key components and concepts include silicon waveguides that route light on a chip, and devices such as Mach-Zehnder interferometers and ring resonators used for signaling, filtering, and modulation. Modulators on silicon often employ carrier-depletion or plasma-dispersion effects in p-n junctions or MOS structures to convert electrical signals into optical ones. Photodetectors are typically realized with germanium integrated on silicon. Because silicon itself is a poor light emitter, lasers are usually added via heterogeneous integration with III–V semiconductors or optical coupling to external light sources. Other elements include arrayed waveguide gratings and multiplexers/demultiplexers for wavelength-division multiplexing, as well as various passive and active optical components for signal processing.

Manufacturability and integration are central strengths: silicon photonics leverages mature CMOS processes to enable dense integration of optical and electronic functions on wafer-scale platforms. Challenges include achieving low propagation loss, efficient fiber-to-chip coupling, thermal sensitivity, and the integration of compact on-chip light sources. Packaging and heat management remain active areas of development.

Applications span data centers, high-performance computing, telecommunications, sensing, and automotive LIDAR. Silicon photonics aims to deliver high-bandwidth, energy-efficient optical interconnects and sensing solutions while leveraging the scalability of silicon-based manufacturing.