Theses Doctoral

Low-loss visible-light integrated photonics: from tunable lasers to frequency combs

Corato Zanarella, Mateus

Over the past decades, integrated photonics has revolutionized the way we generate and manipulate light, employing micro- and nanoscale structures to shrink full optical systems into chips smaller than a fingernail. By leveraging the infrastructure of semiconductor foundries and fabrication processes, the development and deployment of integrated photonic technologies has been greatly accelerated. The main focus has been in applications for infrared light, such as optical interconnects and communication.

Nevertheless, photonic integrated circuits (PICs) have quickly found applications in many other fields, including sensing, ranging, imaging, quantum technologies, biomedicine, spectroscopy, microwave generation, astrophysics, and displays. However, many of these technologies require light at visible wavelengths, where PIC technology is still in its infancy. Visible-light photonics presents several additional and stricter challenges when compared the infrared portion of the spectrum. First, laser sources are not as developed or available.

Second, the sensitivity of devices to fabrication variations and the coupling losses are intensified. Third, the range of transparent materials available for waveguiding is more limited, and their technology is not as mature. Lastly, techniques that work well in the infrared spectrum are not as effective in the visible range due to the remarkably different material properties in this spectral window.In this thesis, we explore integrated photonics in the visible spectrum and focus on solving two of its main challenges: the lack of high-performance laser sources, and the high losses of PICs.

We develop a low loss, high-confinement silicon nitride (SiN) platform and use it to demonstrate high-performance visible-light lasers from near-ultraviolet (near-UV) to near-infrared (near-IR), to probe the limits of absorption and scattering across the visible spectrum, and to generate multi-octave frequency combs with simultaneous infrared and visible light of all colors of the rainbow. Since our SiN platform is compatible with current photonic foundries, our work lays the foundation for fully-integrated, dense and scalable visible-light PIC systems that combine high-performance lasers and ultra-low loss devices. We envision such chip-scale platform to not only transform existing technologies, but to also enable a whole new generation of applications that have so far been impossible, causing tremendous impact in science, medicine and industry.


This item is currently under embargo. It will be available starting 2025-04-13.

More About This Work

Academic Units
Electrical Engineering
Thesis Advisors
Lipson, Michal
Ph.D., Columbia University
Published Here
April 19, 2023