Design and optimization of broadband silicon photonic devices

The integration of photonic systems on a chip offers enhanced performance, functionality, and reliability. While there are various material platforms available for constructing photonic integrated circuits, silicon stands out due to its compatibility with existing fabrication technologies and its high refractive index contrast. These features enable sub-micrometer waveguide scaling and dense packing of optical functions, combined with cost-effective and reliable manufacturing processes. Silicon photonics has already demonstrated its effectiveness in high-speed communication applications, but its potential reaches far beyond that. It shows promise for diverse applications like LIDAR, photonic switching, computing, and sensing, making it a versatile technology with a wide range of possibilities. Consequently, there is a growing demand for efficient and innovative photonic building blocks on the silicon platform to meet the specific requirements of these applications. This thesis focuses on the development of advanced photonic devices tailored for photonic integrated circuits. The first part presents the design and experimental demonstration of compact silicon photonic filters using optimized fast adiabatic waveguides, enabling arbitrarily wide bandwidths. These devices, with the widest bandwidths reported to date, find applications in high-throughput communications and ultra-broadband sensing. Subsequently, a novel deep photonics network architecture is introduced, enabling the rapid design of high-performance, multi-functional photonic devices. A proof-of-concept device with an arbitrary dispersion profile over a wide bandwidth is demonstrated. Lastly, a fabrication variation-aware device design concept is presented, utilizing the deep photonic network architecture to account for the effects of the actual fabrication process. Overall, this work contributes to the development of high-performance and versatile silicon photonic systems for a range of applications.