Materials Science and Engineering doctoral candidate Yiteng Wang has achieved a major breakthrough in integrated photonics, demonstrating visible red lasers grown directly inside silicon nitride photonic chips for the first time. Working with Professor Minjoo Larry Lee of the Department of Electrical and Computer Engineering and collaborators at MIT Lincoln Laboratory, Wang's work bridges two previously incompatible materials systems, opening new pathways for quantum computing, biosensing and augmented reality technologies.
Silicon nitride is essential for light-based technologies, but cannot generate light on its own. While III-V compound materials—made from elements in columns III and V of the periodic table—are widely used in commercial lasers, their crystal structures have made them extremely difficult to integrate with silicon-based materials like silicon nitride.
"Developing this platform required bridging the worlds of III-V materials growth and silicon nitride integrated photonics," said Wang, the study's lead author. "It was incredibly rewarding to see how years of process development and close collaboration with MIT Lincoln Laboratory converged into a working red laser grown right inside a silicon nitride photonics chip."
The collaborative project built upon extensive efforts to overcome material defects that arise when growing III-V compounds on silicon-based platforms. MIT Lincoln Laboratory manufactured silicon nitride photonic templates on 200 mm silicon wafers, featuring precisely defined microscopic "pockets" for growing indium phosphide quantum dot lasers at the Holonyak Micro and Nanotechnology Laboratory (HMNTL).
"This work brings visible-light photonics a step closer to the scalability and integration that silicon photonics has achieved in the infrared," said Lee, director of HMNTL, who led the Illinois effort. Lee is an affiliate of the Department of Materials Science and Engineering and a member of the Illinois Quantum Information Science and Technology Center (IQUIST).
The team is now developing fabrication techniques for optical coupling into silicon nitride waveguides, enabling new types of visible photonic systems. The work was primarily supported by the Defense Advanced Research Projects Agency (DARPA) LUMOS program under the project "Heteroepitaxial III–V/SiNₓ Integrated Photonics (HIP)."
Grainger Engineering Affiliations:
Minjoo L. Lee is a professor of electrical and computer engineering in the Department of Electrical and Computer Engineering. He serves as director of the Holonyak Micro and Nanotechonology Laboratory (HMNTL).