Article
Engineering, Electrical & Electronic
Francesco De Leonardis, Richard A. Soref
Summary: In this study, we theoretically investigate the efficient second harmonic generation (SHG) in a lattice-matched N-doped (GaP)(N) / (Si-2)(M) short-period superlattice integrated in a strip waveguide on the silicon-on-insulator platform. We calculate the X-(2) spectrum and conversion efficiency for different superlattice structures and pump wavelengths.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Kohei Horii, Hiroki Yano, Katsuhiro Hata, Ruizhi Wang, Kazuto Mikami, Kenji Hatori, Koji Tanaka, Wataru Saito, Makoto Takamiya
Summary: This article proposes an 8-bit digital gate driver (DGD) that utilizes a half-bridge digital-to-analog converter IC and two power MOSFETs to achieve a +/- 15V output voltage swing and a large gate current of up to 28A. The DGD effectively drives high-voltage, large-current IGBT modules (HVIGBT) in the 3.0-4.5kV, 1000A range, demonstrating the world's highest records in active gate driving (AGD). Four different gate drive methods are compared and the stop-and-go gate driving is selected for its cost-performance advantage. Finally, a design guideline for AGD in HVIGBTs is established to minimize switching loss (ELOSS) and collector current overshoot (IOVERSHOOT).
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Francesco De Leonardis, Richard A. Soref
Summary: We present a theoretical investigation of efficient second harmonic generation in the cubic lattice-matched N-doped Si/GsP multiple quantum well system integrated in a strip waveguide in the silicon-on-insulator platform. The results show a giant second-order nonlinear optical susceptibility and a maximum conversion efficiency, obtained by engineering the quantum well structure and optimizing the resonance conditions.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Jorge Parra, Juan Navarro-Arenas, Miroslavna Kovylina, Pablo Sanchis
Summary: This article investigates the impact of GST thickness on optical performance in phase-change integrated photonics. It shows that thinner GST thicknesses can lead to the excitation of higher-order modes and a reduction in extinction ratio. These findings are important for designing high-performance GST/Si-based photonic devices.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Electrical & Electronic
Apostolos Tsakyridis, Nikos Terzenidis, George Giamougiannis, Miltiadis Moralis-Pegios, Konstantinos Vyrsokinos, Nikos Pleros
Summary: The paper discusses the challenges and limitations of current electrical DataCenter switches in scaling beyond the 25.6 Tb/s capacity-era and the perspectives and challenges of migrating to Optical Packet Switch (OPS) technologies. The feasibility and performance of OPS schemes are demonstrated through experimental results, showcasing the potential of OPS in overcoming electronic bottlenecks and achieving high switch capacities.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Jinha Lim, Joonsup Shim, Dae-Myeong Geum, Sanghyeon Kim
Summary: This article presents a slot waveguide based on the Ge-on-Si platform and characterizes its performance through numerical design and experimental measurements. The results indicate that the slot waveguide has similar propagation loss to channel waveguides, but higher field confinement, making it suitable for sensing applications.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Ambaresh Sahoo, Dipti Kanika Mahato, A. Govindarajan, Amarendra K. Sarma
Summary: This study presents a detailed investigation on the dynamics of soliton steering in a femtosecond parity-time-symmetric directional coupler. The incorporation of higher-order perturbative effects stabilizes the soliton pulse evolution and enables efficient soliton steering.
Article
Chemistry, Analytical
Masanori Sakamoto, Ken-ichi Saitow
Summary: Silicon is considered a promising enhancement material due to its abundance, low toxicity, and high refractive index. A cost-effective and efficient fabrication method for a field enhancement substrate consisting of a two-dimensional Si wire array (2D-SiWA) was reported, demonstrating high sensor sensitivity and reproducibility. The large-area Si fluorescence sensor fabrication proved to be 50x less expensive, 20x faster, and 60,000x larger than the typical electron beam lithography method.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Tae Wan Park, Woon Ik Park
Summary: This study successfully reduced the writing current of phase change memory (PCM) by employing self-assembly of Si-containing block copolymers (BCPs), which can locally block the current path of the contact between high resistive film and phase-change material, leading to significant power reduction. This BCP-based approach has the potential to be extended to other non-volatile memory devices, such as resistive switching memory and magnetic storage devices.
Article
Engineering, Electrical & Electronic
Yusuke Sawada, Takeshi Fujisawa, Takanori Sato, Kunimasa Saitoh
Summary: This paper proposes a novel wavefront-matching algorithm for the design of silicon waveguides, addressing the instability issue of conventional methods in high-index contrast. The effectiveness of the proposed method is demonstrated through detailed design examples, achieving high conversion efficiency for mode converters.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Siqin Wu, Bo Zhou, Dongpeng Yan
Summary: This work presents a new type of one-dimensional organic metal halide hybrid micro/nanotubes and micro/nanorods with excitation-dependent optical waveguide properties from visible to near-infrared regions, showing low-loss coefficient and high emissive efficiency. Strong intermolecular interactions within the hybrid systems effectively reduce nonradiative transitions and improve quantum efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Yen-Wei Hsueh, Chih-Hsien Cheng, Cai-Syuan Fu, Huai-Yung Wang, Bo-Ji Huang, Gong Lin
Summary: The study demonstrates the all-optical cross-wavelength QAM-OFDM data switching in Si-rich SiC micro-ring waveguide for the first time, achieving a data rate approaching 3 Gbit/s with FEC qualified criteria, SNR of 9.49 dB, BER of 1.4 x 10(-3), and EVM of 33.5%.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2021)
Article
Chemistry, Inorganic & Nuclear
David Jago, Amelia. R. R. Langley, Samantha. G. G. Eaves, Mark. C. C. Walkey, Thea Pulbrook, Stephen. A. A. Moggach, Matthew. J. J. Piggott, Paul. J. J. Low, George. A. A. Koutsantonis
Summary: Multifunctional switches are crucial for the development of smart molecular materials and molecular-electronic applications. The synthesis, structure, and characterization of spiropyrans functionalized with alkynyl-[Ru(dppe)(2)] groups are described. The study demonstrates access to several stable redox states using electrochemical and spectroelectrochemical methods, as well as via acidochromism and photoisomerisation. The spiropyran also exhibits effective insulation properties for electronic communication across the molecular backbone.
DALTON TRANSACTIONS
(2022)
Article
Engineering, Electrical & Electronic
Maciej Smierzchalski, Francesco Foglia Manzillo, Michele Del Mastro, Nicolas Capet, Baptiste Palacin, Ronan Sauleau, Mauro Ettorre
Summary: This study presents the experimental validation of a dual-mode, polarization-agile parallel-fed continuous transverse stub (CTS) antenna architecture, demonstrating excellent performance in both horizontal and vertical polarization. The results pave the way for the realization of dual-circularly polarized beam-scanning antennas with application to broadband and compact Ka-band ground terminals.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Nanoscience & Nanotechnology
Di Wu, Xing Yang, Ningning Wang, Liangjun Lu, Jianping Chen, Linjie Zhou, B. M. Azizur Rahman
Summary: In this study, a multilevel optical memristive switch based on a silicon Fabry-Perot resonator was demonstrated. The interaction between the optical field and GST is greatly enhanced due to the resonant effect, resulting in high transmission contrast and multiple nonvolatile switching levels.
Article
Multidisciplinary Sciences
Hirokazu Masai, Takahiro Ohkubo, Yasuhiro Fujii, Akitoshi Koreeda, Takayuki Yanagida, Toshiaki Ina, Kenji Kintaka
Summary: The study investigates the correlations between structural and physical properties of Ce-doped strontium borate glasses, finding that density-driven molar volume is suitable for evaluating structural data while chemical composition is better for evaluating optical and luminescent data. Borate-rich glasses exhibit stronger luminescence due to Ce3+ and internal quantum efficiency originates from the local coordination states of Ce3+ centers. Comparing numerical data of the matrix helps ensure homogeneous doping of amorphous materials by activators and determines the origin of physical properties.
SCIENTIFIC REPORTS
(2021)
Article
Physics, Applied
Junichi Inoue, Toshiki Kusuura, Ryohei Ueda, Kenji Kintaka, Shogo Ura
Summary: The proposed thin-film narrowband retroreflector is designed for a diverging free-space wave, utilizing a reflective substrate and a focusing grating coupler in a waveguide resonator. It can achieve reflection at a specific resonance wavelength and provide a retroreflection spectrum with a 75% peak value.
APPLIED PHYSICS EXPRESS
(2021)
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
Shogo Ura, Ryugo Tsuji, Junichi Inoue, Kenji Kintaka
Summary: A waveguide grating on a transparent substrate can function as an optical notch filter due to guided-mode resonance, with the filtering wavelength being highly sensitive to the incidence angle. Investigations have shown the potential of a two-dimensional grating for use in three-dimensional angle-fluctuation sensing applications. Sensitivities were estimated for different angles of incidence, azimuth, and polarization, demonstrating different levels of sensitivity for each.
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
Rui Ma, Sander Reniers, Yuya Shoji, Tetsuya Mizumoto, Kevin Williams, Yuqing Jiao, Jos van der Tol
Summary: This paper demonstrates an integrated polarization-independent device that can function as an optical isolator or optical circulator, providing high optical isolation performance and advancing towards multifunctional and high-density PICs.
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
Optics
Toshiya Murai, Yuya Shoji, Tetsuya Mizumoto
Summary: This study presents a scheme for light-induced thermomagnetic recording on a Si photonic platform, where lightwave coupled to a ferromagnetic thin-film magnet causes heating and a decrease in coercive force, leading to magnetization reversal. This scheme enables the realization of on-chip magneto-optical memories on the Si photonic platform without the need for complex drive systems.
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
Engineering, Electrical & Electronic
Keisuke Ozawa, Aika Taniguchi, Ryohei Ueda, Shunsuke Teranishi, Akari Watanabe, Junichi Inoue, Kenji Kintaka, Shogo Ura
Summary: A guided-mode-resonance device was designed and fabricated for narrow-band retroreflection and waveguide input coupling at 1550 nm wavelength. The device consists of a focusing grating coupler integrated in a waveguide cavity resonator constructed by a pair of distributed Bragg reflectors on a reflection substrate. The optimal length for maximum coupling was discussed both theoretically and experimentally.
IEEE PHOTONICS JOURNAL
(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
Zhiyu Yang, Ryo Asai, Junichi Inoue, Kenji Kintaka, Shogo Ura
Summary: A narrow-bandpass filter with a doubly periodic structure in a two-dimensional grating is proposed, achieving a peak transmittance of 96% for a small aperture with specific beam and filter sizes.
2021 IEEE CPMT SYMPOSIUM JAPAN (ICSJ)
(2021)