Phys.org March 15, 2021
To accommodate the volume of wireless telecommunication traffic corresponding increases in bandwidth is necessary. Millimeter wave generation using photonic techniques has so far been limited to the use of near-infrared lasers that are down-converted to the mm Wave region. Such methodologies do not currently benefit from a monolithic architecture and suffer from the quantum defect which can ultimately limit the conversion efficiency. An international team of researchers (Italy, France, UK) has demonstrated intracavity mmWave generation within terahertz quantum cascade lasers over the unprecedented range of 25 GHz to 500 GHz. Through ultrafast time resolved techniques, they highlighted the importance of modal phases and that the process is a result of a giant second-order nonlinearity combined with a phase matched process between the THz and mmWave emission. Importantly, this work opens the possibility of compact, low noise mmWave generation using mode locked THz frequency combs…read more. Open Access TECHNICAL ARTICLE
Temporal and spectral response of mmWave generation from QCL1. Credit: Nature Communications volume 12, Article number: 1427 (2021)