Self-consistent simulations of intracavity terahertz comb difference frequency generation by mid-infrared quantum cascade lasers
Year: 2023
Authors: Popp J., Seitner L., Schreiber MA., Haider M., Consolino L., Sorgi A., Cappelli F., De Natale P., Fujita K., Jirauschek C.
Autors Affiliation: Tech Univ Munich TUM, TUM Sch Computat Informat & Technol, D-85748 Garching, Germany; CNR Ist Nazl Ott, Largo Enrico Fermi 6, I-50125 Florence, Italy; European Lab Nonlinear Spect, Via N Carrara 1, I-50019 Sesto Fiorentino, Italy; Hamamatsu Photon KK, Cent Res Lab, 5000 Hirakuchi,Hamakita Ku, Hamamatsu 4348601, Japan; Tech Univ Munich TUM, TUM Ctr Quantum Engn ZQE, D-85748 Garching, Germany.
Abstract: Portable terahertz (THz) frequency comb sources are highly desired for applications in rotational molecular spectroscopy and sensing. To date, direct THz quantum cascade laser (QCL) frequency comb generation is not achievable at room temperature. However, THz comb generation based on intracavity difference frequency generation (DFG) in mid-infrared (mid-IR) QCLs is a promising alternative. Here, we present a numerical study of THz DFG-QCL comb formation in mid-IR QCLs based on a self-consistent multi-domain simulation approach. The dynamical simulations are performed using our open-source software tool mbsolve, which provides a flexible and efficient codebase for solving the generalized full-wave Maxwell-Bloch equations. Here, DFG in the active region of a dual-wavelength mid-IR QCL is considered for the generation of THz radiation. The mixing process and, thus, THz generation require a high second-order intersubband nonlinear susceptibility in the QCL active region and can be obtained by targeted quantum engineering. The associated nonlinear effects are included in the Hamiltonian of our Maxwell-Bloch simulation approach. All necessary input parameters for the description of the quantum system are determined self-consistently using our in-house ensemble Monte Carlo software tool for stationary carrier transport simulations. Notably, such simulations require a full-wave Maxwell-Bloch solver that does not employ the common rotating wave approximation, as a broadband optical field extending from the THz to the mid-IR region is investigated. Our modeling approach and the obtained simulation results for two THz DFG-QCL comb setups are validated against experimental data, showing reasonable agreement. Furthermore, we obtain a locked frequency modulated comb state for mid-IR and THz regimes. (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Journal/Review: JOURNAL OF APPLIED PHYSICS
Volume: 133 (23) Pages from: 233103-1 to: 233103-16
More Information: The authors acknowledge financial support by the European Union’s QuantERA II (G.A. No. 101’017’733)-QATACOMB Project Quantum correlations in terahertz QCL combs [Funding organisations: DFG-Germany (Project No. 491’801’597), CNR-Italy]; by the European Union’s NextGenerationEU Programme with the I-PHOQS Infrastructure (Nos. IR0000016, ID D2B8D520, and CUP B53C22001750006) Integrated infrastructure initiative in Photonic and Quantum Sciences; by the European Union’s Research and Innovation Programmes Horizon 2020 and Horizon Europe with the Qombs Project (G.A. No. 820’419) Quantum simulation and entanglement engineering in quantum cascade laser frequency combs, the Laserlab-Europe Project (G.A. No. 871’124), and the MUQUABIS Project (G.A. No. 101’070’546) Multiscale quantum bio-imaging and spectroscopy; and by the Italian ESFRI Roadmap (Extreme Light Infrastructure-ELI Project).KeyWords: Perfectly Matched Layer; Room-temperature; Continuous-wave; Modulated Combs; Monte-carlo; Band; Operation; Dynamics; MassDOI: 10.1063/5.0151036ImpactFactor: 2.700Citations: 4data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-09-15References taken from IsiWeb of Knowledge: (subscribers only)
