Proceedings Paper
Engineering, Electrical & Electronic
Toshiya Murai, Yuya Shoji, Tetsuya Mizumoto
Summary: We demonstrate the light-induced thermomagnetic recording of a ferromagnetic thin-film CoFeB placed on a silicon waveguide for the first time, where magnetization reversal is observed when light propagates in the waveguide and heats up the thin-film magnet.
2022 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)
(2022)
Article
Materials Science, Multidisciplinary
Weiwei Zhang, Zhanghua Chen, Vladimir I. Belotelov, Yujun Song
Summary: The Kerr null points of ferromagnetic thin films can be controlled by adjusting the thickness of different material layers. The introduction of non-ferromagnetic materials can enhance the Kerr effect of the ferromagnetic thin films.
Article
Chemistry, Multidisciplinary
Rohit Pachat, Djoudi Ourdani, Maria-Andromachi Syskaki, Alessio Lamperti, Subhajit Roy, Song Chen, Adriano Di Pietro, Ludovic Largeau, Romeo Juge, Maryam Massouras, Cristina Balan, Johannes Wilhelmus van der Jagt, Guillaume Agnus, Yves Roussigne, Mihai Gabor, Salim Mourad Cherif, Gianfranco Durin, Shimpei Ono, Jurgen Langer, Damien Querlioz, Dafine Ravelosona, Mohamed Belmeguenai, Liza Herrera Diez
Summary: The magneto-ionic modulation of the Dzyaloshinskii-Moriya interaction (DMI) and the perpendicular magnetic anisotropy (PMA) in W/CoFeB/HfO2 stacks is investigated by annealing at different temperatures and for varying annealing times. It is found that a large modulation of PMA and DMI is observed in the systems annealed at 390 and 350 degrees C, while no response to voltage is observed in the as-grown samples. The magnetic properties, including domain wall velocity, improve significantly with increasing annealing temperature and time, but the magneto-ionic reversibility is compromised.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Engineering, Electrical & Electronic
Mandan Luo, Qing Yang, Ning Chen, Wei Liao
Summary: This paper studies an integrated optical waveguide current sensor based on silicon photonics and magneto-optical materials, achieving energy coupling between the micro-ring resonator and the magneto-optical thin film through the magneto-optical nonreciprocity effect, and obtaining current information through a Mach-Zehnder interferometer.
IEEE SENSORS JOURNAL
(2022)
Article
Optics
N. S. Shnan, N. Roostaei, S. M. Hamidi
Summary: In this study, the effect of plasmonic and all-dielectric metasurfaces on the magneto-optical response of a 2D periodic structure was investigated theoretically and experimentally. The results showed that the electric and magnetic dipole moments can significantly enhance the magneto-optical response in specific wavelength channels, and the magneto-optical enhancement based on plasmonic hot spots was confirmed.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Optics
Guang Yang, Alexander Sergienko, Abdoulaye Ndao
Summary: LNOI waveguides, as an emerging technology, offer a promising platform for integrated optics with advantages such as modulating mode hybridization, high-efficiency polarization mode conversion, and active switching by external fields. Simplifying fabrication processes and facilitating technological progress in photonics circuits and sensors.
Article
Optics
Yohei Saito, Kota Shikama, Tai Tsuchizawa, Norio Sato
Summary: An optical coupling method with high alignment tolerance through self-written waveguide formation shows promise for co-packaged optics in silicon photonics. By devising a new optical circuit, the researchers achieved efficient coupling between a SiPh chip and a standard single-mode fiber, with higher alignment tolerances compared to conventional coupling methods.
Article
Materials Science, Multidisciplinary
Xiaomin Zhu, Cuicui Zhao, Weiwei Zhang, Bo Zhang, Mengtao Sun, Xinhua Chen, Vladimir Belotelov, Yujun Song
Summary: In this study, structural colors were successfully achieved by constructing CoFeB photonic crystal layers on the surface of a nanoporous aluminum oxide (AAO) substrate using magnetron sputtering deposition. The resulting material showed high resolution, color purity, and saturation in color control.
Furthermore, the study investigated angle-dependent color changes of CoFeB@AAO films by altering the incident light angle, with simulation results consistent with experimental findings, indicating significant practical applications.
This strategy may have great potential applications for solid structure color coatings, anti-counterfeiting and security, information storage, and electromagnetic sensors.
Article
Multidisciplinary Sciences
Ze Jing
Summary: Structural defects have a significant impact on the stability of superconductivity, with the extension of edge cracks in superconducting films affecting the threshold field, avalanche patterns, and multifractal spectrum of the thermomagnetic instability process. This study systematically investigates the effects of edge cracks on the thermomagnetic instability of superconducting thin films. Through simulations, dendritic flux avalanches in thin films are reproduced, and the underlying physical mechanisms are revealed from dissipative vortex dynamics simulations.
NATIONAL SCIENCE REVIEW
(2023)
Article
Optics
Geun Ho Ahn, Alexander D. White, Hyungjin Kim, Naoki Higashitarumizu, Felix M. Mayor, Jason F. Herrmann, Wentao Jiang, Kevin K. S. Multani, Amir H. Safavi-Naeini, Ali Javey, Jelena Vuckovic
Summary: Many attractive photonics platforms lack integrated photodetectors due to material incompatibilities and lack of process scalability. This research shows that tellurium can be evaporated onto photonic chips using a thermal evaporation and deposition technique, resulting in air-stable, high-speed, ultrawide-band photodetectors. These photodetectors demonstrate detection from visible to short-wave infrared, a bandwidth of over 40 GHz, and platform-independent scalable integration with various photonic structures.
Article
Nanoscience & Nanotechnology
Surya Narayan Panda, Sudip Majumder, Arpan Bhattacharyya, Soma Dutta, Samiran Choudhury, Anjan Barman
Summary: Pure spin current generated by spin pumping mechanism, with high efficiency and transparency, is crucial for future spin-orbitronic devices. The giant interfacial spin transparency and its strong dependence on crystal structures of W can contribute significantly to the development of such devices.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Optics
Xinkai Feng, Huaixi Chen, Haizhou Huang, Xinbin Zhang, Xing Cheng, Jiaying Chen, Lei Ma, Huagang Liu, Wanguo Liang, Wenxiong Lin
Summary: A novel fabrication method of PPLN thin film ridge waveguide is proposed in this paper, which uses glue bonding and modulates the vertical refractive index gradient by changing the substrate thickness to achieve broadband SHG. The proposed structure has been verified to improve the power and conversion efficiency of SHG, simplifying the fabrication process of lithium niobate thin film ridge waveguide and having certain significance for photonic chip integration.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Brindaban Ojha, Sougata Mallick, Sujit Panigrahy, Minaxi Sharma, Andre Thiaville, Stanislas Rohart, Subhankar Bedanta
Summary: Magnetic skyrmions are topologically stable spin swirling particles that hold promise for future spintronic devices. The low critical current density required for their motion makes them attractive for energy efficient electronic devices. In this study, the Pt/CoFeB/MgO heterostructures were investigated and skyrmions were successfully stabilized at room temperature. The presence of a low pinning landscape in the samples was confirmed by the distortion of skyrmion shape even under the influence of weak magnetic fields from low moment magnetic tips during magnetic force microscopy (MFM) scans. The threshold current density required to drive the skyrmions in our sample was found to be low, with velocities of few 10 m/s.
Article
Optics
Sean Nelan, Andrew Mercante, Cooper Hurley, Shouyuan Shi, Peng Yao, Benjamin Shopp, Dennis W. Prather
Summary: This study reports a hybrid silicon nitride and lithium niobate folded electro-optic Mach Zehnder modulator, which features small footprint, low voltage, and wide bandwidth. The modulator demonstrates promising performance.
Article
Optics
Yeolheon Seong, Jinwook Kim, Heedeuk Shin
Summary: In this study, a new approach to fiber-array fiber-to-chip couplers is proposed, utilizing a high numerical aperture fiber positioned on a silicon waveguide to achieve high coupling efficiency and broad alignment tolerance ranges.
Article
Engineering, Electrical & Electronic
Daiki Minemura, Shuyuan Liu, Yuya Shoji, Tetsuya Mizumoto
Summary: The proposed 3 dB polarization coupler can convert input light into two out-of-phase or in-phase TM modes, with a 3-step taper structure. By incorporating this coupler into a Mach-Zehnder interferometer, the polarization of the output light can be rotated depending on the phase difference between the two arms. This study optimized the design of the coupler and demonstrated numerically the polarization rotation in an MZI with the proposed couplers.
IEICE ELECTRONICS EXPRESS
(2021)
Article
Physics, Applied
Mario Alberto Serrano-Nunez, Yuya Shoji, Tetsuya Mizumoto
Summary: This study presents the design of an integrated transverse electric mode isolator realized by epitaxial growth of CFO film on a silicon micro-ring resonator structure, with ultra-compact sizes demonstrated numerically. Nonreciprocal phase shift can be maximized by optimizing ring cross-section and improving device performance by decreasing ring size. Optimal results are achieved by reducing ring size, simplifying device design and fabrication.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Optics
Shuyuan Liu, Yuya Shoji, Tetsuya Mizumoto
Summary: The design and fabrication of optical isolators, especially in the TE polarized mode, have long been a challenge in photonic integrated circuits. This study presents a TE mode magneto-optical isolator with adiabatic tapered waveguides for mode conversion, featuring an ultra-narrow structure. The device demonstrates a maximum isolation ratio of 15 dB and an insertion loss of 5 dB under TE mode input at a wavelength of 1537.3 nm.
Article
Engineering, Electrical & Electronic
Mario Alberto Serrano-Nunez, Yuya Shoji, Tetsuya Mizumoto
Summary: This paper experimentally demonstrates a silicon optical isolator using a monolithically integrated cobalt ferrite film as a magneto-optical material, achieving an isolation ratio of 9.6 dB near a wavelength of 1550 nm. The device has a compact size compared to current yttrium iron garnet-based isolators due to the large Faraday rotation coefficient of cobalt ferrite. Furthermore, self-biased isolation is achieved through the strong remanence of cobalt ferrite films, eliminating the need for an external magnet. Cobalt ferrite represents a potential alternative to yttrium iron garnets for realizing practical on-chip isolation devices in silicon photonic integrated circuits due to its small footprint.
IEICE ELECTRONICS EXPRESS
(2022)
Article
Physics, Applied
Shun Yajima, Yuya Shoji
Summary: A photonic integrated circuit-based TSP solver is proposed and simulated, utilizing light's delay time to express the delay between travel points. The solver, comprising semiconductor optical amplifiers and tunable delay lines, is reconfigurable. By using a probabilistic algorithm, polynomial calculation and small footprint complexity are achieved, with a calculation time of 388 ms and footprint within 10 cm squared for a TSP of 100 points.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Optics
Shuyuan Liu, Yuya Shoji, Tetsuya Mizumoto
Summary: This study demonstrates a transverse electric mode magneto-optical isolator based on an asymmetric microring resonator without additional polarization rotators in series. Cerium-substituted yttrium iron garnet is integrated with silicon-on-insulator substrates by wafer bonding to break the Lorentz reciprocity on-chip after applying a unidirectional magnetic field.
Article
Engineering, Electrical & Electronic
Paolo Pintus, Leonardo Ranzani, Sergio Pinna, Duanni Huang, Martin V. Gustafsson, Fotini Karinou, Giovanni Andrea Casula, Yuya Shoji, Yota Takamura, Tetsuya Mizumoto, Mohammad Soltani, John E. Bowers
Summary: The current-driven modulator based on the magneto-optic effect can operate at temperatures as low as 4 K and offer data rates of up to 2 Gbps, potentially enabling large-scale control and readout of quantum computers.
NATURE ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Rui Ma, Sander F. G. Reniers, Yuya Shoji, Tetsuya Mizumoto, Yuqing Jiao, Jos J. G. M. van der Tol, Kevin A. Williams
Summary: This paper demonstrates an on-chip optical circulator on the InP-membrane-on-Si (IMOS) platform. The circulator is composed of two multi-mode interferometers (MMIs), four polarization converters (PCs), and a Cerium-doped Yttrium Iron Garnet (Ce:YIG) die. The Ce:YIG die is bonded on the InP membrane via a thin bonding layer. Nonreciprocal phase shift (NRPS) is employed using a transverse magnetic field. The device functions as a 4-port optical circulator and achieves a maximum optical isolation of 27.0 dB and a minimum optical isolation of 18.6 dB for the TE mode. The proposed methods aim to improve the optical isolation bandwidth.
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2023)
Article
Optics
Shun Yajima, Nobuhiko Nishiyama, Yuya Shoji
Summary: This article demonstrates a magneto-optical switch that responds to signals with a rise time of 200 ps. The switch utilizes a current-induced magnetic field to modulate the magneto-optical effect. Impedance-matching electrodes were designed to apply high-frequency current and accommodate high-speed switching. A static magnetic field generated by a permanent magnet is applied orthogonal to the current-induced fields, acting as a torque to assist in high-speed magnetization reversal.
Proceedings Paper
Engineering, Electrical & Electronic
Toshiya Murai, Yuya Shoji, Tetsuya Mizumoto
Summary: We demonstrate the light-induced thermomagnetic recording of a ferromagnetic thin-film CoFeB placed on a silicon waveguide for the first time, where magnetization reversal is observed when light propagates in the waveguide and heats up the thin-film magnet.
2022 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)
(2022)
