Direkt zum InhaltDirekt zur SucheDirekt zur Navigation
▼ Zielgruppen ▼

Humboldt-Universität zu Berlin - Faculty of Mathematics and Natural Sciences - Optical Systems

Humboldt-Universität zu Berlin | Faculty of Mathematics and Natural Sciences | Department of Physics | Optical Systems | Publications | Wideband, high-resolution terahertz spectroscopy by light-induced frequency tuning of quantum-cascade lasers

Tasmim Alam, Martin Wienold, Xiang Lü, Klaus Biermann, Lutz Schrottke, Holger T Grahn, and Heinz-Wilhelm Hübers (2019)

Wideband, high-resolution terahertz spectroscopy by light-induced frequency tuning of quantum-cascade lasers

Optics Express, 27(4):5420–5432.

Near-infrared optical excitation enables wideband requency tuning of terahertz quantum-cascade lasers. In this work, we demonstrate the feasibility of the approach for molecular laser absorption spectroscopy. We present a physical model which explains the observed frequency tuning characteristics by the optical excitation of an electron-hole plasma. Due to an improved excitation configuration as compared to previous work, we observe a single-mode continuous-wave frequency coverage of as much as 40 GHz for a laser at 3.1 THz. This represents, for the same device, a ten-fold improvement over the usually employed tuning by current. The method can be readily applied to a large class of devices.

Quantenkaskadenlaser, Terahertz-Spektroskopie