Compact coherent sub-terahertz sources based on quantum dot laser frequency combs

• Applicant: Privatdozent Dr. Stefan Breuer
• Subject Area: Experimental Condensed Matter Physics ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 438641949

The aim of this research fellowship project is to significantly enhance the experimental and theoretical foundations of frequency comb laser based coherent sub-terahertz synthesis. By designing, developing, processing, characterizing and demonstrating a novel class of near-infrared emitting monolithic frequency comb quantum dot ring lasers with multiple spatially located absorber sections and a reconfigurable antenna, we will constitute a novel miniaturized electrically-injected photonic platform for the generation and radiation of sub-terahertz signals into free space. We will make use of the particular ultra-fast gain and absorption dynamics and unprecedented high optical-to-microwave conversion efficiency of quantum dot lasers. Designing and distributing multiple absorbers sections along a ring laser cavity will yield major decisive advantages: the generation and reconfigurable control of sub-terahertz frequencies by colliding pulse mode-locking and access to ultra-high pulse train stability with low phase noise, yielding high spectral purity, and low amplitude noise. We aim to comprehensively study the optical and microwave emission dynamics of such prototypic electrically-injected sub-terahertz transmitters with narrow radio-frequency line width and at sub-terahertz frequency tunable emission that might help opening novel applications in terahertz communications, radioastronomy, optical sensing and in quantum optics.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Federico Capasso