Quantum Dot Lasers Achieve Breakthrough on-chip Integration and Longevity
Jul. 25, 2025 –
The quest for fully integrated photonic chips, capable of processing light signals on a single silicon platform, has long faced a formidable challenge: seamlessly incorporating light sources directly onto silicon.
A recent study led by researcher Rosalyn Koscica from the University of California, show significant advancements in monolithically integrating indium arsenide (InAs) quantum dot (QD) lasers directly onto silicon photonic chiplets.
Titled “Quantum Dot DBR Lasers Monolithically Integrated on Silicon Photonics by In-Pocket Heteroepitaxy,” (1) the study was published in the IEEE Journal of Lightwave Technology.
While silicon excels in processing optical signals, it is fundamentally inefficient at generating light. It needs the integration of III-V semiconductor materials, which are excellent light emitters, onto silicon substrates. However, the path to monolithic integration has been fraught with difficulties stemming from inherent material mismatches.
Monolithic integration, where III-V semiconductor lasers are directly grown onto silicon photonic chips, could revolutionize data communications and other applications by leveraging existing foundry capabilities for scalable, high-volume production.
This vision faces significant material mismatches between silicon and III-V materials that hinder its progress. These include fundamental differences in lattice constant and coefficient of thermal expansion, leading to the generation of crystalline imperfections known as threading dislocation (TD) and misfit dislocation (MD) defects.