Article
Optics
Alexey Kiselev, Vitaly V. Ionin, Anton A. Burtsev, Nikolai N. Eliseev, Vladimir A. Mikhalevsky, Natalya A. Arkharova, Dmitry N. Khmelenin, Andrey A. Lotin
Summary: The paper presents a study on the dynamics of phase transitions in GST thin films determined by the rate of change in their optical coefficients. It was found that the time for reflectivity change was shorter than that of transmissivity, with the estimated crystallization rate being higher than the reamorphization rate.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Optics
Junxia Zhou, Youting Liang, Zhaoxiang Liu, Wei Chu, Haisu Zhang, Difeng Yin, Zhiwei Fang, Rongbo Wu, Jianhao Zhang, Wei Chen, Zhe Wang, Yuan Zhou, Min Wang, Ya Cheng
Summary: Utilizing the PLACE technique, on-chip light amplification with integrated optical waveguide fabricated on erbium-doped thin-film lithium niobate on insulator (TFLNOI) was demonstrated with a maximum internal net gain of 18 dB. This work opens the way for the monolithic integration of diverse active and passive photonic components on the TFLNOI platform.
LASER & PHOTONICS REVIEWS
(2021)
Article
Chemistry, Multidisciplinary
Jianghong Wu, Maoliang Wei, Jianglong Mu, Hui Ma, Chuyu Zhong, Yuting Ye, Chunlei Sun, Bo Tang, Lichun Wang, Junying Li, Xiaomin Xu, Bilu Liu, Lan Li, Hongtao Lin
Summary: The study demonstrates the potential of Bi2O2Se in silicon photonic circuits, showing high-performance characteristics for photodetectors suitable for spectroscopy, sensing, and communication applications.
Article
Optics
Anoopshi Johari, Sanjeev Naithani, Baljinder Kaur, Abhinav Bhatnagar, Brajesh Kumar Kaushik
Summary: This article introduces a photodetector that utilizes the phase-changing material Ge2Sb2Te5 (GST) integrated with a silicon on insulator (SOI) waveguide, and analyzes its application in communication and optical fiber communication. The analysis shows that GST has potential as a promising material for photodetection applications.
OPTICAL ENGINEERING
(2023)
Article
Multidisciplinary Sciences
Pengyan Wen, Preksha Tiwari, Svenja Mauthe, Heinz Schmid, Marilyne Sousa, Markus Scherrer, Michael Baumann, Bertold Ian Bitachon, Juerg Leuthold, Bernd Gotsmann, Kirsten E. Moselund
Summary: This study successfully achieved the seamless integration of III-V nanostructures on silicon and demonstrated the performance of scaled and waveguide coupled III-V photodiodes. Furthermore, it was found that the temperature increase during device operation as an emitter was only approximately 15 K according to experimental and simulation results.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Xin He, Yinchang Ma, Chenhui Zhang, Aiping Fu, Weijin Hu, Yang Xu, Bin Yu, Kai Liu, Hua Wang, Xixiang Zhang, Fei Xue
Summary: Using protonic gating technology, this study creates a series of metastable ferroelectric phases in layered alpha-In2Se3 transistors and demonstrates their reversible transitions. Protons can be incrementally injected or extracted by varying the gate bias, enabling controllable tuning of the ferroelectric alpha-In2Se3 protonic dynamics and obtaining numerous intermediate phases. The volatile gate tuning of alpha-In2Se3 protonation and the formation of metastable hydrogen-stabilized alpha-In2Se3 phases are unexpectedly discovered. Ultralow gate voltage switching of different phases is achieved, providing a possible avenue for accessing hidden phases in ferroelectric switching.
Article
Optics
Jia Du, Zhangjian Mu, Lan Li, Junying Li
Summary: Ge2Sb2Te5 (GST) is a successful nonvolatile phase change material that can be reversibly switched between amorphous and crystalline phases by nanosecond laser pulses. High-energy laser irradiation can modify molecular bonds in the GST thin film, forming different local structures. The GeTe4-nGen subsystem plays a decisive role in laser-induced crystallization of GST.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Yue Wang, Changqing Guo, Mingfeng Chen, Yuhan Liang, Haojie Han, Hetian Chen, Yuanhua Lin, Di Yi, Houbing Huang, Ce-Wen Nan, Jing Ma
Summary: Mechanically driven reversible polarization switching has been achieved in imprinted ferroelectric BiFeO3 thin films, allowing for the design of ferroelectric nanodomain structures without the need for voltage application. This reversible switching is enabled by the flexoelectric effect, piezoelectric effect, and internal upward built-in field in the BiFeO3 films. The study provides valuable insights into the mechanism and control of mechanically driven polarization switching, and offers guidance for the development of ferroelectric-based electro-mechanical microelectronics.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Zhao Guan, Yun-Kangqi Li, Yi-Feng Zhao, Yue Peng, Genquan Han, Ni Zhong, Ping-Hua Xiang, Jun-Hao Chu, Chun-Gang Duan
Summary: The study demonstrates the formation of out-of-plane domains in Hf0.5Zr0.5O2 (HZO) ferroelectric films through mechanical writing, enabling wider flexoelectric applications and ultrahigh-density storage.
Article
Optics
Yuan Zhou, Yiran Zhu, Zhiwei Fang, Shupeng Yu, Ting Huang, Junxia Zhou, Rongbo Wu, Jian Liu, Yu Ma, Zhe Wang, Jianping Yu, Zhaoxiang Liu, Haisu Zhang, Zhenhua Wang, Min Wang, Ya Cheng
Summary: This work presents a robust low-loss optical interface for passive/active lithium niobate photonics by tiling passive and active thin film lithium niobate (TFLN) substrates. The tiled substrates allow for patterning the integrated device's mask using a single continuous photolithography process. The interface loss of the tiled substrate is measured to be as low as 0.26 dB. A four-channel waveguide amplifier with net gains of 5 dB and 8 dB at 1550 nm and 1530 nm wavelengths, respectively, is achieved through this approach. The robust low-loss optical interface facilitates the development of large-scale high-performance photonic devices with on-chip light sources and amplifiers.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Physical
Tobias Kohler, Efi Hadjixenophontos, Yug Joshi, Ke Wang, Guido Schmitz
Summary: Silicon is a promising candidate for battery anodes due to its large theoretical storage capacity, but challenges such as volume expansion and kinetic limitations need to be addressed through nanostructuring. By using electrochemical quartz crystal microbalance (QCM), researchers were able to study the in-situ solid electrolyte interface (SEI) formation on Si films, leading to the discovery of reversible adsorption of Li2O to the SEI layer, which accounts for half of the battery storage. This reversible adsorption is influenced by factors such as cycling window, rate, and anode thickness, indicating a field-driven layer growth mechanism.
Article
Materials Science, Multidisciplinary
Sipan Yang, Jinbin Xu, Yaqian Li, Liying Wu, Xueling Quan, Liucheng Fu, Min Liu, Xiulan Cheng
Summary: A novel deeply etched ridge-waveguide tapered grating coupler embedded with modified slots on X-cut single crystal lithium niobate thin film was successfully demonstrated for effective light-coupling and bidirectional transmission of optical beams. The fabricated device exhibited low insertion loss and wide optical bandwidth, showing good agreement between modeling and experimental results, which may promote the development of large scale photonic integrated components.
Article
Engineering, Electrical & Electronic
Sunaina Priyadarshi, Abidur Rahaman, Mohammad Masum Billah, Sabiqun Nahar, Jin Jang
Summary: A compact DC-DC converter has been developed based on low-temperature poly-Si oxide thin film transistors. It shows good performance with reduced area and small pumping capacitors. Experimental results demonstrate that the converter achieves an output voltage of 14.5V and an output power of 790 μW for a 3V input voltage, with a maximum power efficiency of 83.3% at a load current of 90 μA.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Chemistry, Physical
Yuhang Guan, Yuqing Zhang, Jinxiong Li, Jiye Li, Yuhan Zhang, Zhenhui Wang, Yuancan Ding, Mansun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: In recent years, high-k gate dielectrics have received increasing attention in amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) due to the need for stronger gate controllability. This study developed an ultra-thin top-gate insulator of atomic-layer-deposited (ALD) HfOx for amorphous indium-gallium-zinc oxide (a-IGZO) TFTs. However, the reliability of the 4-nm HfOx-gated a-IGZO transistor is poor due to interface defects caused by the interface reaction between HfOx and a-IGZO during the ALD process. To improve stability, the a-IGZO channel is pre-treated with strong oxidizing plasma. However, further reducing HfOx thickness increases gate leakage current.
APPLIED SURFACE SCIENCE
(2023)
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
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
Engineering, Electrical & Electronic
Ranepura Hewage Neranjith, Yuya Shoji, Tetsuya Mizumoto
Summary: This paper extends previous work on a microring resonator-type serial-to-parallel conversion scheme for all-optical label processing on silicon photonic platform. By introducing rib waveguides, propagation loss is reduced to sub-dB/cm values, allowing for multibit conversion. Despite free-carrier dispersion in silicon, serial-to-parallel conversion was demonstrated on a 4-bit label, even at low pump power levels.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
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)
