Article
Physics, Multidisciplinary
Fumiya Sekiguchi, Hideki Hirori, Go Yumoto, Ai Shimazaki, Tomoya Nakamura, Atsushi Wakamiya, Yoshihiko Kanemitsu
Summary: The impact of phonon excitations on the photoexcited carrier dynamics in lead-halide perovskite CH3NH3PbI3 was investigated, showing that strong terahertz excitation can prolong the cooling time of hot carriers. The results demonstrate that phonon excitation significantly perturbs the carrier relaxation dynamics in halide perovskites through the coupling between transverse- and longitudinal-optical phonons.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
L. Guiramand, J. E. Nkeck, X. Ropagnol, T. Ozaki, F. Blanchard
Summary: By utilizing a novel pulse compression technique and a 400 µJ ytterbium laser, we have achieved a state-of-the-art terahertz (THz) source at room temperature with a record efficiency of 1.3%, generating an average power of 74 mW and a focus of 400 kV/cm. This source exhibits unmatched characteristics in generating intense and powerful THz pulses simultaneously, and it remains highly scalable compared to existing Ti:sapphire-based THz sources pumped in the millijoule range.
PHOTONICS RESEARCH
(2022)
Article
Optics
A. Ovchinnikov, O. Chefonov, M. B. Agranat, A. Kudryavtsev, E. D. Mishina, A. A. Yurkevich
Summary: The study demonstrates that under the action of high-intensity terahertz pulses, an inhomogeneous distribution of charge carrier concentration is formed in silicon, which persists for several microseconds. This inhomogeneity is attributed to a sharp increase in the rate of filling the conduction band with free carriers in the subsurface input layer of the silicon wafer at field strengths above 15 MV/cm.
Article
Multidisciplinary Sciences
Hong-Yi Lei, Fang-Zheng Sun, Tian-Ze Wang, Hao Chen, Dan Wang, Yan-Yu Wei, Jing-Long Ma, Guo-Qian Liao, Yu-Tong Li
Summary: This research focuses on the highly efficient production of millijoule-level terahertz pulses by irradiating the rear side of a metal foil with a 10-TW femtosecond laser pulse. By analyzing the terahertz and electron emission and conducting particle-in-cell simulations, the physical reasons for the efficient terahertz generation are discussed. The resulting focused terahertz electric field strength exceeding 2 GV/m is experimentally justified.
Article
Physics, Applied
Yuxuan Wei, Jiaming Le, Li Huang, Chuanshan Tian
Summary: This work presents a convenient approach to generate strong broadband terahertz (THz) pulses with a tunable center frequency using low-cost crystalline quartz. The THz conversion efficiency in quartz reaches 0.05%, comparable to LiNbO3 at room temperature, while providing a much broader THz spectral range. This not only addresses the urgent need for a light source in nonlinear THz spectroscopy beyond 2 THz but also offers an alternative route in selecting nonlinear optical crystals for frequency conversion.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Xianze Meng, Kang Wang, Xieqiu Yu, Yingying Ding, Yushan Zeng, Ting Lin, Renyu Feng, Wenkai Li, Yi Liu, Ye Tian, Liwei Song
Summary: We propose a scheme for intense terahertz generation from DSTMS crystal driven by a high-power optical parametric chirped pulse amplifier. The generated terahertz energy is up to 175 μJ with a peak electric field of 17 MV/cm. This study demonstrates the relationship between terahertz energy, conversion efficiency, and pump fluence, providing a powerful driving light source for strong-field terahertz pump-probe experimentation.
Article
Physics, Applied
Di Li, Jibo Fu, Peng Suo, Wenjie Zhang, Bo Lu, Xian Lin, Xiaona Yan, Bo Li, Guohong Ma, Jianquan Yao
Summary: In this study, the photocarrier dynamics and thickness dependent interlayer coherent phonon modes in PdSe2 films were systematically investigated using ultrafast optical pump-probe spectroscopy. The analysis based on a simple one-dimensional chain model revealed important parameters for the interlayer force constant and sound velocity in PdSe2 films. These experimental findings pave the way for designing and developing optoelectronic and nanomechanic devices based on PdSe2.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Meenhaz Ansari, Subhana Nafees, S. S. Z. Ashraf, Absar Ahmad
Summary: This paper presents a theoretical investigation on the generation of Cerenkov emission of terahertz acoustic phonons in bilayer graphene. The study focuses on the dependencies of phonon emission spectrum and intensity on factors such as phonon frequency, drift velocity, electron temperature, concentration, and emission angle. The results show that the magnitude of the emission spectrum increases at larger drift velocities and applied electric fields, with the peak shifting towards higher frequencies. The study highlights the significance of bilayer graphene in acousto/optoelectronic device applications and high-frequency phonon spectrometers.
JOURNAL OF APPLIED PHYSICS
(2022)
Editorial Material
Physics, Applied
Tom S. Seifert, Liang Cheng, Zhengxing Wei, Tobias Kampfrath, Jingbo Qi
Summary: This editorial reviews the recent developments and applications, current understanding of the physical processes, and future challenges and perspectives of broadband spintronic terahertz emitters.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
Yu He, Haohan Shi, Nan Xue, Alexander Magunia, Shaohua Sun, Jingjie Ding, Bitao Hu, Zuoye Liu
Summary: This theoretical study investigates the excitation and manipulation of a two-level system with ultrashort intense extreme-ultraviolet laser fields. The focus is on the dynamical phase excursion of the energy states during the interaction and the resulting spectral modifications. The analysis includes fitting absorption line shapes using the Fano profile, quantifying the asymmetry parameter and dipole phase offset, and employing nonperturbative analytical calculations to understand the dependence of the dipole phase shift on the external field. The validity of the formulas is confirmed by comparing their predictions with numerical results.
Article
Optics
Qili Tian, Hanxun Xu, Yi Wang, Yifan Liang, Yuemei Tan, Xiaonan Ning, Lixin Yan, Yingchao Du, Renkai Li, Jianfei Hua, Wenhui Huang, Chuanxiang Tang
Summary: The study demonstrates an efficient method for generating high-field terahertz (THz) pulse train in congruent lithium niobate (LN) crystals driven by temporally shaped laser pulses. It successfully achieved narrowband THz pulses with sub-percent level conversion efficiency and multi MV/cm peak field, showing potential for generating mJ-level narrow-band THz pulse trains with further improvements in conversion efficiency using smaller pump beam sizes.
Article
Optics
N. A. Abramovsky, S. B. Bodrov, E. S. Efimenko, Y. Avetisyan, M. I. Bakunov
Summary: Cherenkov-type terahertz radiation produced by optical rectification in LiNbO3 can undergo strong spectral broadening in the regime of multiphoton laser absorption. This effect can be utilized to enhance the bandwidth of optical-to-terahertz converters based on optical rectification.
Article
Physics, Applied
Eva Diaz, Alberto Anadon, Martina Morassi, Michel Hehn, Aristide Lemaitre, Jon Gorchon
Summary: This work focuses on the full characterization of terahertz pulses confined in waveguides. Terahertz photoconductive switch detectors were fabricated and used to sample the electrical pulses. Two calibration methods were developed to accurately characterize the pulse amplitude. These techniques provide a reliable tool to explore nonlinear phenomena at high THz intensities.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
S. Xu, N. Hunter, H. Zobeiri, H. Lin, W. Cheng, X. Wang
Summary: This study investigates the energy transport and temperature difference between optical phonons (OPs) and acoustic phonons (APs) in 2D materials under focused photon irradiation. A thermal field invariant is proposed to distinguish the temperatures of OPs and APs. The real thermal conductivity of 2D WS2 is measured based on AP temperature, and the energy coupling factor between OPs and APs is determined.
MATERIALS TODAY PHYSICS
(2022)
Article
Physics, Applied
Nathalie Lander Gower, Shiran Levy, Silvia Piperno, Sadhvikas J. Addamane, John L. Reno, Asaf Albo
Summary: We conducted an experimental study on a new design for a terahertz quantum cascade laser (THz QCL) that combines two-well injector and direct-phonon scattering schemes. This design improves the performance of the lasers by using a direct phonon scattering scheme for depopulating the lower laser level and reducing the overlap with the doped region. The design also achieves efficient isolation of active laser levels and shows potential for higher operating temperatures than the current records.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Maxime Chambonneau, Qingfeng Li, Vladimir Yu. Fedorov, Markus Blothe, Kay Schaarschmidt, Martin Lorenz, Stelios Tzortzakis, Stefan Nolte
Summary: Research shows that by precompensating for nonlinear focal shift, semiconductor-metal ultrafast laser welding can be achieved, resulting in welds with shear joining strengths of up to 2.2 MPa. Material analyses shed light on the physical mechanisms involved during the interaction.
LASER & PHOTONICS REVIEWS
(2021)
Article
Materials Science, Multidisciplinary
Dimitris Karanikolopoulos, Emmanouil Gagaoudakis, Sotiris Droulias, Dimitrios Louloudakis, Kyriakos Mouratis, Maria Polychronaki, Georgios E. Katsoprinakis, Elias Aperathitis, Dimitra Vernardou, Vassilis Binas, Constantinos Kalpouzos, George Kiriakidis, Emmanuel Koudoumas, Alexandros Lappas, Panagiotis A. Loukakos
Summary: This study investigates the optical properties of pristine and Mg-doped vanadium dioxide films under optical excitation using femtosecond pump-probe spectroscopy. The results demonstrate that the Mg-doped film has a faster temporal response and shows promise for applications requiring ultrafast optical switching capabilities.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Chemistry, Physical
Ioannis A. Poimenidis, Michael D. Tsanakas, Nikandra Papakosta, Argyro Klini, Maria Farsari, Stavros D. Moustaizis, Panagiotis A. Loukakos
Summary: The study demonstrates that laser-nanostructured Nickel electrodes have higher efficiency and stability in alkaline electrolysis, with hydrogen production efficiency increased by 3.7 times compared to untreated Nickel electrodes. Additionally, a novel approach is proposed to enhance the stability of current density during electrolysis, further improving the hydrogen production process.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Multidisciplinary
Emmanouil Nikoloudakis, Maria Pigiaki, Maria N. Polychronaki, Alexandra Margaritopoulou, Georgios Charalambidis, Efthymis Serpetzoglou, Anna Mitraki, Panagiotis A. Loukakos, Athanassios G. Coutsolelos
Summary: In this research, diphenylalanine dipeptide was covalently attached to a tripyridyl porphyrin macrocycle, imparting self-assembling properties to the resulting hybrid used for non-noble metal photocatalytic hydrogen evolution studies. The self-assembling nanostructures of the hybrid were found to enhance hydrogen production in the photocatalytic system. This was supported by fluorescence and transient absorption experiments shedding light on electron transfer processes during photocatalysis.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Chemistry, Physical
Ioannis A. Poimenidis, Nikandra Papakosta, A. Manousaki, Argyro Klini, M. Farsari, Stavros D. Moustaizis, Panagiotis A. Loukakos
Summary: A novel approach of nanostructuring the electrode surface and electrodeposition of nickel particles has been employed to enlarge the electrocatalytic area of electrodes in an alkaline electrolysis setup. The resulting electrodes exhibit significantly increased hydrogen evolution reaction (HER) activity and produce more hydrogen gas under actual hydrogen production conditions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Review
Optics
Maxime Chambonneau, David Grojo, Onur Tokel, Fatih Omer Ilday, Stelios Tzortzakis, Stefan Nolte
Summary: The article reviews the physical mechanisms inhibiting sufficient energy deposition inside silicon with femtosecond laser pulses, as well as the strategies established so far for bypassing these limitations. These solutions have allowed addressing numerous applications by employing longer pulses, femtosecond-pulse trains, and surface-seeded bulk modifications.
LASER & PHOTONICS REVIEWS
(2021)
Article
Optics
Anastasios D. Koulouklidis, Dimitris Mansour, Vladimir Yu Fedorov, Dimitris G. Papazoglou, Stelios Tzortzakis
Summary: This experimental study demonstrates that 2D Airy wave packets can generate intense curved two-color filaments, emitting terahertz radiation with unique characteristics. The curvature of the plasma channel causes THz waves emitted from different longitudinal regions of the plasma to propagate in different directions, resulting in non-concentric THz cones in the far-field. These cones exhibit different cone angles and polarization, attributed to the generation and propagation of the two-color 2D Airy driving fields in the nonlinear crystal, forming the curved plasma filament.
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
Optics
Panagiotis Konstantakis, Paul E. Dufour, Maria Manousidaki, Anastasios D. Koulouklidis, Stelios Tzortzakis
Summary: We demonstrate the spectral shaping of supercontinuum generation in liquids using engineered Bessel beams and artificial neural networks. The study shows that neural networks can output the experimental parameters for generating a custom spectrum experimentally.
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
Materials Science, Multidisciplinary
Ioannis Poimenidis, Nikandra Papakosta, Argyro Klini, Maria Farsari, Stavros Moustaizis, Panagiotis Loukakos
Summary: In this study, periodic nanostructures on nickel and iron sheets were fabricated and used as electrodes in an alkaline SCES. The electrochemical evaluation showed improved hydrogen production efficiency and increased charge storage capacity of the nanostructured electrodes.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
R. Cominotti, H. A. M. Leymann, J. Nespolo, J. M. Manceau, M. Jeannin, R. Colombelli, I. Carusotto
Summary: The coherent nonlinear response of electrons in semiconductor quantum wells to resonant electromagnetic radiation is theoretically studied. The study is based on the time-dependent Schrodinger-Poisson equation and the results are interpreted with approximated analytical formulas. The redshift of the resonance frequency and the competition between coherent nonlinearities and incoherent saturation effects are observed and discussed. The optical nonlinearity is estimated across different frequency ranges, which is important for ongoing experiments and the exploration of quantum optical phenomena.
Article
Materials Science, Multidisciplinary
Ioannis A. Poimenidis, Nikandra Papakosta, Argyro Klini, Maria Farsari, Stavros D. Moustaizis, Michalis Konsolakis, Panagiotis A. Loukakos
Summary: In this study, we investigated the electrochemical characteristics of Nickel Foam (NF) electrodes decorated with various thicknesses of Ni nanoparticles using the Pulsed Laser Deposition technique. The NF electrode decorated with 300 nm Ni nanoparticles exhibited improved electrochemical performance with reduced overpotential values and a lower Tafel slope compared to the bare NF electrode. Furthermore, the Ni/NF 300 electrode showed a 15-fold increase in electrochemically active surface area (ECSA) compared to the NF electrode.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2024)
Proceedings Paper
Materials Science, Multidisciplinary
Ioannis A. Poimenidis, Stavros D. Moustaizis, Nikandra Papakosta, Michael D. Tsanakas, Argyro Klini, Panagiotis A. Loukakos
Summary: In this study, a two-step electrode fabrication process was used to increase the electrocatalytic area and enhance the hydrogen evolution reaction (HER). Nickel electrodes were laser-nanostructured and subsequently galvanostatically electrodeposited, which is a novel approach for HER electrodes. The electrodes were characterized using SEM and EDX analysis. The electrochemical evaluation showed improved values of overpotential, Tafel slope, and double layer capacitance compared to the literature. The stability of the electrodes was tested by evaluating their overpotential at a high current density.
MATERIALS TODAY-PROCEEDINGS
(2022)
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.
