News Item
Optics
Spencer W. Jolly
Summary: A diffractive axicon can create intricate connections between topological charges and frequencies of ultrashort laser pulses, resulting in a diverse range of coiled light structures.
News Item
Optics
Philippe St-Jean
Summary: This paper presents a novel solid-state laser that can generate a large array of phase-locked optical vortices with tunable orbital angular momentum.
Editorial Material
Optics
Gianluca Ruffato
Summary: A recent publication suggests a solution to overcome the limitations of optical techniques and high-intensity beams by probing highly-intense vortex pulses with a structured reference beam.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Da-Jie Yang, Song-Jin Im, Yang Li, Chol-Song Ri, Kum-Song Ho, Ji-Song Pae, Qu-Quan Wang
Summary: This study provides insights into the complex plasmon behaviors with the physical dimension of orbital angular momentum (OAM) and proves that plasmonic nanostructures can function as efficient antennas to control the power of OAM beams. These findings expand our knowledge of nanoplasmonics in the OAM area and have promising applications in quantum information processing and dynamic sensing of ultraweak biosignals.
Article
Chemistry, Multidisciplinary
Da-Jie Yang, Ji-Cai Liu
Summary: In this study, efficient and selective high-order resonances were demonstrated in symmetric and asymmetric plasmonic nanoparticles using vortex beams. A pure high-order resonance was observed in symmetric nanoparticles configured with a complete nanoring lying on the focal center. Asymmetric nanoparticles configured with a complete ring off the beam center or a splitting nanoring showed multiple resonances influenced by the ring's geometry, position, orientation, and photon OAM. These findings contribute to the understanding and control of OAM-involved light-material interactions in asymmetric nanosystems.
Article
Optics
Jingying Miao, Shencheng Fu, Xin Li, Hongfang Liu, Xintong Zhang, Haiyang Xu, Yichun Liu
Summary: Holography is used as a feasible method for information encryption, and a serial coding system based on a plasmonic holographic disk utilizing the spin and orbital angular momenta of photons is designed. The accurate distinction of the polarization state and topological charge of the vortex light field enables stable readout of the encrypted holographic grating array.
Article
Optics
Xiang-Yu Zeng, Yu-Qin Zhang, Rui-Rui Zhang, Xiao-Rong Ren, Zi-Jun Zhan, Man-Na Gu, Rui Sun, Chun-Xiang Liu, Chuan-Fu Cheng
Summary: Metasurfaces with orthogonal nano-slit pairs arranged on spirals are proposed to generate vector beams of Bell-like states and slanted polarizations. The design is based on the theoretically derived parameter condition for manipulation of the two vector vortex modes, satisfied by matching the rotation order m, the spiral order n, and incident polarization helicity sigma. Linear polarization states of the vector beams are controlled by the initial orientation angle of slit pairs.
Article
Multidisciplinary Sciences
Xiyuan Lu, Mingkang Wang, Feng Zhou, Mikkel Heuck, Wenqi Zhu, Vladimir A. Aksyuk, Dirk R. Englund, Kartik Srinivasan
Summary: The authors demonstrate a method for generating orbital angular momentum (OAM) using photonic crystal ring resonators, while maintaining high cavity quality factors (up to 10^6). By ejecting high angular momentum states of a whispering gallery mode (WGM) microresonator through a grating-assisted mechanism, a scalable and chip-integrated solution for OAM generation is achieved.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yang Ming, Yuan Liu, Wei Chen, Yusen Yan, Huiguo Zhang
Summary: Researchers have investigated the design of nonlinear metamaterials to generate and modulate entangled photons by adjusting the geometry and orientation of nanoantennas, resulting in the effective generation of orbital angular momentum entangled states. This provides a flexible platform for quantum photonic applications.
Article
Physics, Applied
Qiao Jiang, Hong Xiang, Dezhuan Han
Summary: This study proposes a method to design a plasmonic metasurface that can control the generation and superposition of surface plasmon polariton (SPP) vortices, demonstrating that the superposition of SPP vortices can be accurately controlled by the polarization states of the incidence, providing a feasible way to design miniaturized photonic devices.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
Jonas Waetzel, Primoz Rebernik Ribic, Marcello Coreno, Miltcho B. Danailov, Christian David, Alexander Demidovich, Michele Di Fraia, Luca Giannessi, Klavs Hansen, Spela Krusic, Michele Manfredda, Michael Meyer, Andrej Mihelic, Najmeh Mirian, Oksana Plekan, Barbara Ressel, Benedikt Rosner, Alberto Simoncig, Simone Spampinati, Matija Stupar, Matjaz Zitnik, Marco Zangrando, Carlo Callegari, Jamal Berakdar, Giovanni De Ninno
Summary: This study proposes a laser-based scheme for noninvasive ultrafast control of magnetic moments at the nanoscale. The scheme allows for control of the spatial extent, direction, and strength of atomic-scale charge current loops, and provides a quantitative estimate of the generated local moments.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Grant W. Henderson, Gordon R. M. Robb, Gian-Luca Oppo, Alison M. Yao
Summary: In this study, we model the propagation of far-red-detuned optical vortex beams through a Bose-Einstein condensate using nonlinear Schrödinger and Gross-Pitaevskii equations. We demonstrate the formation of coupled light-atomic solitons that rotate azimuthally before moving off tangentially, carrying angular momentum. The number and velocity of solitons depend on the orbital angular momentum of the optical field. By using a Bessel-Gauss beam, we increase radial confinement to allow solitons to rotate with a fixed azimuthal velocity. Our model provides a highly controllable method for channeling a BEC and atomic transport.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Eva Prinz, Grisha Spektor, Michael Hartelt, Anna-Katharina Mahro, Martin Aeschlimann, Meir Orenstein
Summary: By tailoring the local and global geometries of vortex generators, arbitrary switching in the delivered plasmonic angular momentum can be achieved, providing a new method for plasmonic manipulation. The precise control over the generation and rotation direction of high-order plasmonic vortices was demonstrated, as well as the capability to create complex topological fields.
Article
Optics
Kayn A. Forbes
Summary: Optical helicity is a fundamental property of light, similar to energy and momentum. In the conventional description of light as plane waves, the optical helicity is proportional to the degree of circular polarization. However, this study shows that tightly focused optical vortices can generate nonparaxial fields with a contribution to the optical helicity density that is independent of the polarization state of the source paraxial field. This finding challenges the previous understanding and suggests that unpolarized light can exhibit optical activity and chiral light-matter interactions.
Review
Optics
Jian Chen, Chenhao Wan, Qiwen Zhan
Summary: The combination of photonic OAM and SAM provides additional information for new sensing mechanisms and light-matter interactions. Diverse photonic SAM and OAM states can be generated through careful engineering of optical fields. Specifically engineered photonic AM states have potential applications in optical tweezers, directional coupling, and optical information transmission and processing.
ADVANCED PHOTONICS
(2021)
Article
Chemistry, Physical
Keiichiro Shiraga, Yasuhiro Fujii, Akitoshi Koreeda, Koichiro Tanaka, Takashi Arikawa, Yuichi Ogawa
Summary: This study compared the broadband terahertz and low-frequency Raman spectroscopy of liquid water to address challenges regarding the interpretation of the intermolecular stretching mode. The experiment demonstrated a significant redshift and broadening in the intermolecular stretching mode obtained via terahertz spectroscopy compared to Raman, attributed to enhanced dynamical collectivity. The temperature and isotope dependences emphasize the role of oscillation mass in determining the intermolecular stretching lineshape, while quantum effects are important in both terahertz and low-frequency Raman spectra.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Multidisciplinary Sciences
T. Notake, T. Iyoda, T. Arikawa, K. Tanaka, C. Otani, H. Minamide
Summary: The interaction between THz electromagnetic waves and a metal micro-helix can result in two types of anisotropic re-emissions, which can be beneficial for the development of a smart antenna with broadband multiplexing/demultiplexing ability and directional adaptivity. Advanced measurement techniques have the potential to lead to the creation of novel functional THz devices.
SCIENTIFIC REPORTS
(2021)
Article
Optics
Tomoki Hiraoka, Takashi Arikawa, Hiroaki Yasuda, Yuta Inose, Norihiko Sekine, Iwao Hosako, Hiroshi Ito, Koichiro Tanaka
Summary: The study focused on the injection-locking properties of a resonant-tunneling-diode terahertz oscillator in the small-signal injection regime, showing that injection locking significantly reduced the emission spectrum linewidth. Experimental results indicated that the locking range was proportional to the injection amplitude, and an increase in injection amplitude led to a decrease in noise component and increase in injection-locked component.
Article
Physics, Applied
Satoshi Kusaba, Kenji Watanabe, Takashi Taniguchi, Kazuhiro Yanagi, Koichiro Tanaka
Summary: In monolayer WSe2, the rise dynamics of out-of-plane polarized photoluminescence from spin-forbidden dark excitons under resonant excitation to bright excitons have been studied, showing a finite rise time and suggesting the importance of intermediate states in the relaxation pathway. Exciton-exciton scattering is found to promote faster relaxation to the spin-forbidden dark excitons.
APPLIED PHYSICS LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Ryota Aoki, Kento Uchida, Koichiro Tanaka
Summary: This study investigates a method of inducing topological phase transitions through polarization-controlled infrared excitation and experimentally studies the phenomenon in Td-WTe2 thin films. The experimental results show that polarization-selective excitation leads to the rapid loss of carrier distribution, making it difficult to control the photo-induced phase transition.
Article
Chemistry, Analytical
Francois Blanchard, Takashi Arikawa, Koichiro Tanaka
Summary: In this study, a simple method is proposed to improve the spatial uniformity of two-dimensional terahertz (THz) beam imaging. By fully illuminating the sample using conventional optical microscope objectives and using a normalized background frame information map as a calibration tool, spatial variations in the THz images can be corrected to obtain a flat two-dimensional field. The results suggest that the implementation of dynamic intensity profile correction is promising for real-time electro-optical imaging of THz beams.
Article
Multidisciplinary Sciences
Tomoki Hiraoka, Yuta Inose, Takashi Arikawa, Hiroshi Ito, Koichiro Tanaka
Summary: This paper introduces a resonant-tunneling-diode terahertz oscillator that achieves passive mode-locking and frequency-comb generation through optical feedback. The oscillator, based on a semiconductor device, covers the frequency range of 0.1 to 2 THz. With external bias modulation, the spacing between the comb lines is significantly reduced. A simulation model successfully reproduces the mode-locking behavior. This oscillator can serve as a future frequency standard for terahertz sensing and wireless communications.
NATURE COMMUNICATIONS
(2022)
Article
Optics
F. Blanchard, J. E. Nkeck, L. Guiramand, S. Zibod, K. Dolgaleva, T. Arikawa, K. Tanaka
Summary: This study demonstrates the ability of the surfaces of SrTiO3 crystals at room temperature to act as ultrafast sensors, enabling sub-picosecond switching through the Kerr effect and recording polar THz intensity with spatial resolution below the diffraction limit through THz-field-induced dipole alignment followed by multi-picosecond relaxation time recovery. The contrast sensitivity and spatial resolution achieved by the STO sensor are significantly superior to those of present-day near-field THz sensors based on the linear Pockels effect, providing a new strategy for building an ultrafast space-time THz memory.
Article
Multidisciplinary Sciences
Kento Uchida, Satoshi Kusaba, Kohei Nagai, Tatsuhiko N. Ikeda, Koichiro Tanaka
Summary: In this study, coherent exciton emission in mono-layer WSe2 at room temperature was observed using high-harmonic spectroscopy. The dynamics of Floquet states of excitons were found to be reflected in the coherent exciton emission spectrum. This provides a new approach to Floquet engineering and allows control of quantum materials through pulse shaping of the driving field.
Article
Multidisciplinary Sciences
Zhenya Zhang, Fumiya Sekiguchi, Takahiro Moriyama, Shunsuke C. Furuya, Masahiro Sato, Takuya Satoh, Yu Mukai, Koichiro Tanaka, Takafumi Yamamoto, Hiroshi Kageyama, Yoshihiko Kanemitsu, Hideki Hirori
Summary: The authors studied HoFeO3 crystal using multicycle THz magnetic pulses enhanced strongly by spiral-shaped microstructure. The observed Faraday ellipticity demonstrates second- and third-order harmonics of the magnetization oscillation and an asymmetric oscillation behavior. The ability to drive a spin system to state far from the equilibrium is indispensable for investigating spin structures of antiferromagnets and their functional nonlinearities for spintronics.
NATURE COMMUNICATIONS
(2023)
