Search
Results
-
Field-enhancing tapered planarized waveguides for THz quantum cascade laser frequency combs
(2022)EPJ Web of Conferences ~ EOS Annual Meeting (EOSAM 2022)We present a new planarized waveguide geometry for THz quantum cascade laser frequency combs with improved waveguide losses, RF and thermal dissipation properties. Ridge devices display broadband free-running comb states, and the THz emission can be further broadened by RF injection. Tapered waveguide devices feature a strong field-enhancement effect, which results in an improved comb performance. This includes free-running comb states ...Other Conference Item -
THz QCL combs under strong RF injection: temporal dynamics and harmonic states
(2022)Proceedings of SPIE ~ Novel In-Plane Semiconductor Lasers XXIIn this work present high performance QCL-based THz combs operating on fundamental and harmonic comb states operating up to 110 K in the spectral region from 2 to 4 THz . We employ double-metal, Copper- based laser resonators planarized with a polymer allowing high performance with CW operation up to 118 K . Such waveguide layout allows as well optimized RF coupling facilitating injection of high RF power. We analyze the laser emission ...Other Conference Item -
Spectral phase relation in broadband THz quantum cascade laser frequency combs under strong RF modulation
(2022)Proceedings of SPIE ~ Quantum Sensing and Nano Electronics and Photonics XVIIITHz QCLs are promising sources towards achieving octave-spanning comb operation and self-referencing in a monolithic device. We investigate the spectral mode phase relations by means of SWIFT of free running and strongly RF modulated devices. The inspected QCLs are based on an octave-spanning, heterogeneous and a 1.8 THz spanning, homogeneous active region design. The extracted neighboring mode phase differences from SWIFT of free running ...Other Conference Item -
Shifted Wave Interference Fourier Transform Spectroscopy of Harmonic and Fundamental RF Injection-Locked THz Quantum Cascade Laser Frequency Combs
(2021)2021 27th International Semiconductor Laser Conference (ISLC)Shifted Wave Interference Fourier Transform Spectroscopy allows us to reveal the temporal intensity profiles of RF injection-locked fundamental and harmonic comb states of a broadband, multi-stack THz Quantum Cascade Laser. Depending on the injection power and frequency AM and FM modulated emission can be observed.Other Conference Item -
Broadband active and passive photonics with planarized THz quantum cascade lasers
(2022)Other Conference Item -
Planarized tapered waveguides for high-temperature THz quantum cascade laser frequency combs
(2022)2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)We present a novel planarized double metal waveguide platform for high-performance THz quantum cascade laser frequency combs. The waveguides are embedded in a low-loss polymer (BCB) and have an extended top metallization, resulting in lower waveguide losses and improved RF and thermal properties. A further performance improvement is observed for waveguides with a tapered profile due to nonlinearity-enhancing effects. These free-running ...Other Conference Item -
High speed response of a Hot Electron Bolometer to a picosecond optical THz source and to a THz QCL comb up to 31GHz
(2022)2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)We have investigated the frequency response of a phonon-cooled Hot Electron Bolometer (HEB) made from an ultrathin superconducting niobium nitride film. We have used short optical pulses and a broadband spectrum analyzer to record the impulse response of the HEB. To interpret the experimental results, we have used numerical calculations based on the two temperature (2T) theoretical model.Other Conference Item -
Frequency comb operation of antenna coupled terahertz quantum cascade ring lasers
(2023)Proceedings of SPIE ~ Quantum Sensing and Nano Electronics and Photonics XIXOther Conference Item -
THz optical beatnote detection with a fast hot electron bolometer operating up to 31 GHz
(2023)Proceedings of SPIE ~ Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XVIWe studied the performance of hot-electron bolometers (HEBs) operating at THz optical frequencies based on superconducting niobium nitride films. We report on large optical bandwidth measurement of the voltage response of the detector carried out with different THz sources. We show that the impulse response of the fully packaged HEB at 7.5 K has a 3 dB cut-off around 2 GHz, but a considerable detection capability is also observed above ...Other Conference Item -
FM to AM Transition of RF Driven THz QCL fundamental and Harmonic Comb States
(2022)2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)We measure temporal intensity profile by means of Shifted Wave Interference Fourier Transform Spectroscopy of strong RF injected heterogeneous THz QCLs showing a strong AM emission with pulses as short as 6 ps. Additionally, we measure with SWIFTS fundamental as well as harmonic comb states under RF injection which exhibit clear FM emission and its transition to AM as a function of the RF power.Other Conference Item