Article
Optics
Yu Wu, Christopher A. Curwen, Mohammad Shahili, John L. Reno, Benjamin S. Williams
Summary: This paper demonstrates the use of radiofrequency injection locking and spectral broadening in a terahertz quantum-cascade vertical-external-cavity surface-emitting laser. By injecting RF current modulation, the round-trip frequency can be pulled and locked. The lasing spectrum can be broadened from 14 GHz to a maximum of 110 GHz with injected RF power, opening up possibilities for active mode-locking and picosecond pulse generation in THz lasers.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Qi Yang, Jicheng Zhang, Xuemin Wang, Zhiqiang Zhan, Tao Jiang, Jia Li, Ruijiao Zou, Keyu Li, Fengwei Chen, Weidong Wu
Summary: This work presents a dual ridge terahertz quantum cascade laser lasing at 3.1 THz and analyzes its performance in detail. The experimental results provide a reference for realizing high-power terahertz quantum cascade lasers and offer guidance for the structural design of multiple ridges or laser arrays.
Article
Optics
Luigi Consolino, Annamaria Campa, Michele De Regis, Francesco Cappelli, Giacomo Scalari, Jerome Faist, Mattias Beck, Markus Rosch, Saverio Bartalini, Paolo De Natale
Summary: Full phase control of THz-emitting QCL combs has been demonstrated, opening new perspectives for demanding applications. A new method, Small Optical Frequency Tuning (SOFT), has been proposed to control the emission frequencies of a THz QCL comb using a simple experimental setup, allowing tweaking of the complex refractive index without destabilizing laser gain. The SOFT actuator has been characterized and shown to be suitable for frequency and phase stabilization of THz QCL combs.
LASER & PHOTONICS REVIEWS
(2021)
Article
Engineering, Electrical & Electronic
Eleanor Nuttall, Yingjun Han, Diego Pardo, Sanchit S. Kondawar, Nick Brewster, Mohammed Salih, Lianhe Li, Michael D. Horbury, A. Giles Davies, Edmund H. Linfield, Hui Wang, Paul Dean, Brian N. Ellison, Alexander Valavanis
Summary: Waveguide integration of terahertz quantum cascade lasers (THz QCLs) is achieved above 4.7 THz frequencies. A fabrication method involving precision micromachining, diamond-turning, and electroless-plating is utilized to manufacture hollow rectangular waveguides with diagonal feedhorns integrated. The surface roughness at the level of approximately 1 μm is attained, allowing radiation outcoupling in the 4.75-5.05 THz band with a divergence angle less than 5 degrees along the QCLs substrate plane.
ELECTRONICS LETTERS
(2023)
Article
Physics, Applied
Yue Shen, Anthony D. Kim, Mohammad Shahili, Christopher A. Curwen, Sadhvikas Addamane, John L. Reno, Benjamin S. Williams
Summary: An amplifying quantum-cascade (QC) metasurface, a key component of the QC vertical-external-cavity surface-emitting-laser (VECSEL), was studied using reflection-mode terahertz time domain spectroscopy. Perfect absorption at zero bias, increase in reflectance with bias, and significant phase modulation associated with metasurface resonance were observed. The results provide insight into the interaction between intersubband QC-gain material and metasurface, and modify the design rules for biased and unbiased QC-VECSELs.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
David Stark, Muhammad Mirza, Luca Persichetti, Michele Montanari, Sergej Markmann, Mattias Beck, Thomas Grange, Stefan Birner, Michele Virgilio, Chiara Ciano, Michele Ortolani, Cedric Corley, Giovanni Capellini, Luciana Di Gaspare, Monica De Seta, Douglas J. Paul, Jerome Faist, Giacomo Scalari
Summary: Electroluminescence from L-valley transitions in n-type Ge/Si0.15Ge0.85 quantum cascade structures has been reported, with two peaks indicating suboptimal injection in the upper state of the radiative transition. The emission efficiency of the Ge/SiGe structure is found to be one order of magnitude lower compared to a similar GaAs/AlGaAs structure.
APPLIED PHYSICS LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Michael Jaidl, Maximilian Beiser, Miriam Giparakis, Martin Alexander Kainz, Dominik Theiner, Benedikt Limbacher, Marie Christine Ertl, Aaron Maxwell Andrews, Gottfried Strasser, Juraj Darmo, Karl Unterrainer
Summary: This study presents a heterogeneous terahertz quantum cascade laser consisting of five individual active regions based on a three-well, LO-phonon depopulation design. The lasers can operate in both pulsed and continuous-wave modes, emitting in a spectral range from 1.9 to 4.5 THz, with broad bandwidth.
Article
Nanoscience & Nanotechnology
Franco Prati, Massimo Brambilla, Marco Piccardo, Lorenzo Luigi Columbo, Carlo Silvestri, Mariangela Gioannini, Alessandra Gatti, Luigi A. Lugiato, Federico Capasso
Summary: Nonlinear interactions in physical systems can lead to symmetry breaking phenomena such as modulation instabilities, which may result in the formation of optical solitons. The generalized Lugiato-Lefever equation predicts the existence of optical solitons in ring quantum cascade lasers with an external driving field, enabling the bistability mechanism. The study also shows the possibility of phase solitons and cavity solitons formation in the driven emitter, making them promising for applications such as frequency combs and encoding information.
Article
Nanoscience & Nanotechnology
Sergej Markmann, Martin Franckie, Shovon Pal, David Stark, Mattias Beck, Manfred Fiebig, Giacomo Scalari, Jerome Faist
Summary: This study investigates the nonlinear system properties of an unbiased quantum cascade structure using two-dimensional THz spectroscopy, revealing multiple nonlinear signals and subband lifetimes of 4-8 ps. Coherent population exchange among intersubband levels is observed during relaxation, confirmed by simulations. Experimental results are modeled using a time-resolved density matrix based on the Lindblad master equation, providing qualitative replication and insight into their microscopic origin.
Article
Optics
Kumar Kinjalk, Daniel Andres Diaz-Thomas, Zeineb Loghmari, Michael Bahriz, Roland Teissier, Alexei N. Baranov
Summary: In this study, InAs-based quantum cascade lasers (QCLs) operating near 14 μm were reported to have a threshold current density J(th) as low as 0.6 kA/cm(2) at room temperature. The achieved threshold was lower than that of the best reported InP-based QCLs without facet treatment, partially due to an increased separation between the upper transition level and the next one in the active quantum wells of the QCL design employed.
Article
Optics
Chao Ning, Tian Yu, Shuman Liu, Jinchuan Zhang, Lijun Wang, Junqi Liu, Ning Zhuo, Shenqiang Zhai, Yuan Li, Fengqi Liu
Summary: We demonstrate GaSb-based interband cascade lasers with high output power and good reliability.
CHINESE OPTICS LETTERS
(2022)
Article
Chemistry, Analytical
Yu Ma, Weijiang Li, Yuanyuan Li, Junqi Liu, Ning Zhuo, Ke Yang, Jinchuan Zhang, Shenqiang Zhai, Shuman Liu, Lijun Wang, Fengqi Liu
Summary: The present study proposes a terahertz quantum cascade laser frequency comb (THz QCL FC) with a semi-insulated surface plasma waveguide. It exhibits a low threshold current density, high power, and a wide current dynamic range. The optimized gain dispersion value and nonlinear susceptibility are achieved through a hybrid bound-to-continuum active region with a semi-insulated surface plasmon waveguide. The device shows stable frequency comb operation within a current dynamic range of over 97%, without the need for extra dispersion compensator. A total comb spectral emission of about 300 GHz centered around 4.6 THz is achieved for the device with a length of 3 mm and width of 150 μm. At 10 K, it demonstrates a maximum output power of 22 mW with an ultra-low threshold current density of 64.4 A·cm-2.
Article
Engineering, Electrical & Electronic
Zhijian Shen, Zhuo Deng, Xuyi Zhao, Jian Huang, Lu Yao, Xinbo Zou, Chunfang Cao, Qian Gong, Baile Chen
Summary: This article demonstrates the optical properties of a long-wave infrared InAs/GaAs sub-monolayer quantum dot quantum cascade photodetector grown on a GaAs substrate, showing its potential competitiveness in long-wave infrared imaging applications.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Instruments & Instrumentation
Aleksandr Kuzmicz, Emilia Pruszynska-Karbownik, Kamil Piersscinski, Piotr Gutowski, Dorota Pierscinska, Kamil Janus, Krzysztof Michalak, Grzegorz Sobczak, Maciej Sakowicz
Summary: This study analyzes the theoretical and experimental aspects of mid-infrared quantum cascade laser Fabry-Perrot waveguides with various sidewall geometries. It compares the performance of wet etched double trench geometry with dry etched single ridge geometry at different sidewall angles, finding that the latter operates in the fundamental transverse mode for larger waveguide widths. The optimal sidewall angle is around 64 degrees.
INFRARED PHYSICS & TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Tudor Olariu, Mattias Beck, Jerome Faist
Summary: We present a systematic study of the optical design, fabrication, and characterization of quantum cascade laser devices with a frequency around 4.7 THz. The measured devices exhibit consistent spectral performance, with approximately 75% of them having their emission frequency within a 6 GHz band relative to their nominal value. Additionally, we explain how processing variability is exploited to shift the emission frequency post-process and post-measurement.
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2023)
Article
Physics, Multidisciplinary
Erika Cortese, Ngoc-Linh Tran, Jean-Michel Manceau, Adel Bousseksou, Iacopo Carusotto, Giorgio Biasiol, Raffaele Colombelli, Simone De Liberato
Summary: In doped quantum wells, electrons and holes cannot form bound states through usual Coulomb interaction, but can do so when embedded in a cavity where photons exchange provides effective attraction. Spectroscopic observation shows that increased coupling between light and matter can lead to the creation of bound states below the ionization threshold, demonstrating the importance of light-matter coupling in quantum material engineering.
Article
Physics, Applied
Baptiste Chomet, Djamal Gacemi, Angela Vasanelli, Carlo Sirtori, Yanko Todorov
Summary: The research presents an alternative detection scheme for terahertz signals based on an optomechanical detector, combining a split-ring resonator and a mechanical resonator to read arbitrary periodic modulations on terahertz beams. Two Fourier sampling methods for the envelope of the terahertz signal are demonstrated, utilizing the mechanical resonator as a reference oscillator.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
P. Quach, A. Jollivet, A. Babichev, N. Isac, M. Morassi, A. Lemaitre, P. A. Yunin, E. Frayssinet, P. de Mierry, M. Jeannin, A. Bousseksou, R. Colombelli, M. Tchernycheva, Y. Cordier, F. H. Julien
Summary: We report on a GaN/AlGaN quantum cascade detector operating in the terahertz spectral range. The detector exhibited a peak photocurrent at 5.7 THz with a responsivity of 0.1 mA/W at 10 K. The device was grown by metal organic chemical vapor deposition on a c-sapphire substrate and relied on polar GaN/AlGaN step quantum wells.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
M. Lagree, M. Jeannin, G. Quinchard, O. Ouznali, A. Evirgen, V Trinite, R. Colombelli, A. Delga
Summary: The study focuses on the light-matter coupling phenomenon in midinfrared quantum cascade detectors, demonstrating that a refined semiclassical coupled modes theory is required to accurately describe the spectral features in the photocurrent. Through simulations, the resonant tunneling from the polaritonic states is identified as the predominant extraction mechanism in the system.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Multidisciplinary
M. Knorr, J. M. Manceau, J. Mornhinweg, J. Nespolo, G. Biasiol, N. L. Tran, M. Malerba, P. Goulain, X. Lafosse, M. Jeannin, M. Stefinger, I Carusotto, C. Lange, R. Colombelli, R. Huber
Summary: The ultrafast scattering dynamics of intersubband polaritons in dispersive cavities embedding GaAs/AlGaAs quantum wells were directly studied using a noncollinear pump-probe geometry with phase-stable midinfrared pulses. Selective excitation of the lower polariton at a frequency of similar to 25 THz and at a finite in-plane momentum k(parallel to) resulted in the emergence of a narrowband maximum in the probe reflectivity at k(parallel to) = 0. A quantum mechanical model identified the underlying microscopic process as stimulated coherent polariton-polariton scattering.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Mario Malerba, Simone Sotgiu, Andrea Schirato, Leonetta Baldassarre, Raymond Gillibert, Valeria Giliberti, Mathieu Jeannin, Jean-Michel Manceau, Lianhe Li, Alexander Giles Davies, Edmund H. Linfield, Alessandro Alabastri, Michele Ortolani, Raffaele Colombelli
Summary: The concept of strong light-matter coupling has been demonstrated in semiconductor structures, allowing for the study of light-matter interaction in subwavelength-sized nanocavities. A novel nano spectroscopy technique using an inserted polymer layer and atomic force microscopy enables the observation of cavity losses and the characterization of near-field coupling.
Article
Physics, Fluids & Plasmas
Deepa Verma, Armelle Michau, Angela Vasanelli, Carlo Sirtori, Khaled Hassouni
Summary: The kinetic behavior of electrons in a thin semiconductor layer subjected to voltage pulses is investigated using particle-in-cell/Monte Carlo collision simulations based on the electron Boltzmann equation. The results show that highly nonlinear interactions between the space-charge field and the electrons lead to oscillations due to the relatively high plasma density. The dynamics and phase-space trajectories of the excited electron waves depend on the doping level. Strong oscillations occur during the relaxation phase and are subsequently damped with time scales between 100 and 400 fs, decreasing with doping level. The emitted power spectra exhibit a high-energy band and a low-energy peak, attributed to bounded plasma resonances and a sheath effect, respectively.
PHYSICS OF PLASMAS
(2023)
Article
Nanoscience & Nanotechnology
Laurent Boulley, Thomas Maroutian, Paul Goulain, Andrey Babichev, Anton Egorov, Lianhe Li, Edmund Linfield, Raffaele Colombelli, Adel Bousseksou
Summary: We demonstrate low temperature deposition conditions for VO2 phase change material that are compatible with III-V semiconductors used in optoelectronic applications. The VO2 coated thin films grown on GaAs exhibit a 50% change in optical reflectivity and a significant variation in electric conductivity between insulating and metallic states. We also study the functionalization of mid-infrared QCLs with VO2 layers to engineer their laser emission properties.
Article
Materials Science, Multidisciplinary
Jiawen Liu, Djamal Gacemi, Konstantinos Pantzas, Gregoire Beaudoin, Isabelle Sagnes, Angela Vasanelli, Carlo Sirtori, Yanko Todorov
Summary: An optomechanical scheme is presented to achieve light-controlled logic functions by combining an electromagnetic resonator with a strongly nonlinear nanomechanical oscillator. The nonlinear mechanical oscillations, controlled by external drives, are sensitive to incident light due to enhanced light-matter interactions. Reconfigurable logic functions (NOT, XOR, OR, AND) can be realized by adjusting the initial mechanical configurations to obtain various responses to input optical signals.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Paul Goulain, Chris Deimert, Mathieu Jeannin, Stefano Pirotta, Wojciech Julian Pasek, Zbigniew Wasilewski, Raffaele Colombelli, Jean-Michel Manceau
Summary: Continuously graded parabolic quantum wells are used to overcome the limitations of square quantum wells at terahertz frequencies. Microcavity intersubband polaritons are formed at frequencies as low as 1.8 THz, with ultra-strong coupling sustained up to 200 K. The use of sub-wavelength resonators preserves the ultra-strong coupling regime, making it a potential approach for generating non-classical light.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Optics
Yuhao Jin, Fangyuan Sun, Jinghao Li, Chuan Seng Tan, Kian Hua Tan, Satrio Wicaksono, Carlo Sirtori, Soon Fatt Yoon, Qi Jie Wang
Summary: Tunable single-mode slot waveguide QCL array has been developed for high-resolution and highly sensitive trace gases sensing in the MIR region. This laser array exhibits a tuning range of approximately 12 cm(-1) and has been successfully used for individual gas sensing and absorption measurements of mixed gases.
Article
Multidisciplinary Sciences
Francesco Pisani, Djamal Gacemi, Angela Vasanelli, Lianhe Li, Alexander Giles Davies, Edmund Linfield, Carlo Sirtori, Yanko Todorov
Summary: In this study, a quantum infrared detector operating in the ultra-strong light-matter coupling regime driven by collective electronic excitations is explored. The strong collective electronic resonances are found to optimize photodetectors operating in this regime. These findings introduce a new approach to conceive optoelectronic devices based on the coherent interaction between electrons and photons.
NATURE COMMUNICATIONS
(2023)
Article
Environmental Sciences
Jingfeng Liu, Luyao Xin, Lixia Qin, Taiyang Zhang, Xiangqing Li, Shi-Zhao Kang
Summary: A flexible SERS sensing platform was developed to monitor the concentration of benzotriazole in water. The platform showed high sensitivity with a detection limit of 0.01 nmol L-1 and excellent repeatability and reproducibility. This research is important for real-time monitoring of trace benzotriazole in tap water.
Article
Materials Science, Multidisciplinary
Daniele De Bernardis, Mathieu Jeannin, Jean-Michel Manceau, Raffaele Colombelli, Alessandro Tredicucci, Iacopo Carusotto
Summary: We analyze the effect of a strong perpendicular magnetic field on an intersubband transition in a disordered doped quantum well strongly coupled to an optical cavity. The magnetic field changes the lineshape of the intersubband optical transition and introduces a novel form of magnetic-field-induced cavity protection, which significantly reduces the polariton linewidth.
Article
Materials Science, Multidisciplinary
Wojciech J. Pasek, Chris Deimert, Paul Goulain, Jean-Michel Manceau, Raffaele Colombelli, Zbig R. Wasilewski
Summary: This study investigates the influence of nonparabolicity on the formation of multisubband plasmons and develops a model to predict absorption peaks. The results show that including the dependence on both energy and wave function with respect to the in-plane wave vector significantly improves the accuracy of the predictions. The model can be applied to a wide range of nanostructures.
