Article
Optics
A. Munoz de las Heras, I. Carusotto
Summary: In this work, we propose and theoretically characterize optical isolators consisting of an all-dielectric and nonmagnetic resonator. These isolators have an intensity-dependent refractive index and a strong coherent field propagating in a single direction. The isolation mechanism is based on the breaking of optical reciprocity induced by the asymmetric action of four-wave mixing processes. We provide a physical understanding of the isolation mechanism in terms of the Bogoliubov dispersion of collective excitations and investigate specific setups.
Article
Optics
Alexander D. White, Geun Ho Ahn, Kasper Van Gasse, Ki Youl Yang, Lin Chang, John E. Bowers, Jelena Vuckovic
Summary: This article demonstrates an integrated approach for passively isolating a continuous-wave laser using the non-reciprocal Kerr nonlinearity in ring resonators. By using silicon nitride as the model platform, the authors achieve single ring isolation of 17-23 dB with 1.8-5.5 dB insertion loss, and cascaded ring isolation of 35 dB with 5 dB insertion loss. They also demonstrate hybrid integration and isolation with a semiconductor laser chip using these devices.
Article
Optics
Michele Cotrufo, Andrea Cordaro, Dimitrios L. Sounas, Albert Polman, Andrea Alu
Summary: This article presents bias-free optical metasurfaces with a large non-reciprocal response for free-space radiation based on silicon thermo-optic nonlinearities. These ultrathin devices offer the potential for signal processing and protection of high-power laser cavities.
Article
Multidisciplinary Sciences
Shixing Yuan, Liao Chen, Ziwei Wang, Wentao Deng, Zhibo Hou, Chi Zhang, Yu Yu, Xiaojun Wu, Xinliang Zhang
Summary: An integrated terahertz isolator based on a nonreciprocal resonator with optimized magneto-optical properties and loss is reported, allowing for unidirectional propagation and operation at different central frequencies. This on-chip isolator will inspire more solutions for integrated terahertz nonreciprocal devices and has practical feasibility for applications such as terahertz sensing.
NATURE COMMUNICATIONS
(2021)
Article
Computer Science, Information Systems
Tianyang Chen, Xiaodong Chen, Yuan Yao, Xiaoming Liu, Junsheng Yu
Summary: The study focuses on improving the Gaussian beam mode analysis for analyzing 3-D multi-reflector systems, and successfully designing a 3-D double ellipsoidal reflector system operating at 183 GHz. The results demonstrate the efficiency and accuracy of 3-D GBMA in comparison with physical optics, showcasing its potential for precise and rapid calculations in 3-D quasi-optical systems.
Review
Materials Science, Multidisciplinary
Karthik Srinivasan, Bethanie J. H. Stadler
Summary: This article discusses the challenges and developments of passive optical isolators in silicon photonics. New processing techniques and material combinations have made it possible to achieve small footprint isolators on silicon waveguide structures, and integrated isolators have demonstrated high isolation ratios and low insertion loss.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Engineering, Electrical & Electronic
Benjamin Baumann, Bersant Gashi, Dominik Meier, Christian Zech
Summary: The submillimeter-wave quasi-optical high-resolution imaging system operates between 343GHz and 423GHz with a bandwidth of 80GHz, utilizing a frequency-modulated continuous wave radar sensor. It is capable of generating high-resolution power- and elevation-profile images of various samples under test, with a lateral resolution limit in the order of wavelength.
IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
(2022)
Article
Nuclear Science & Technology
Chao Zhang, Fukun Liu, Xiaojie Wang, Dajun Wu, Yunying Tang, Liyuan Zhang, Hanlin Wang
Summary: The CFETR is the next-generation device for China's magnetic controlled fusion program, using high power millimeter-wave injection for heating and current drive. A 3D visual quasi-optical design tool has been developed for the Upper Launchers, optimizing the system layout and beam propagations accurately. Evaluation results showed minimum concentration radius of mm-wave beams and peak heat load on the mirrors.
FUSION ENGINEERING AND DESIGN
(2021)
Article
Optics
Mengjie Yu, Rebecca Cheng, Christian Reimer, Lingyan He, Kevin Luke, Eric Puma, Linbo Shao, Amirhassan Shams-Ansari, Xinyi Ren, Hannah R. Grant, Leif Johansson, Mian Zhang, Marko Loncar
Summary: Optical isolators are essential for protecting lasers from unwanted reflections and maintaining phase-stable coherent operation in optical systems. Integrated chip-scale optical systems require fully integrated optical isolators, but existing approaches face challenges in material integration. In this study, a non-reciprocal electro-optic isolator on thin-film lithium niobate is achieved, with high performance in terms of isolation and insertion loss. This represents an important advancement towards practical on-chip optical isolators.
Article
Engineering, Electrical & Electronic
Mohamed Mamdouh M. Ali, Mahmoud Elsaadany, Shoukry i I. Shams, Ke Wu
Summary: To increase the bandwidth of mmW Y-junction ferrite circulators, a novel design technique is proposed in this article. The designed Y-junction ferrite circulator achieves a bandwidth of more than 20% at 60 GHz and demonstrates good performance in terms of matching level, isolation, and insertion loss. The effect of input power and ambient temperature on the circulator's performance is also studied.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Optics
Yannick D'Mello, Santiago Bernal, Adam Helmy, Essam Berikaa, Olivier Carpentier, Imtiaz Alamgir, Md Samiul Alam, Eslam El-Fiky, David Plant
Summary: The study presents the design of an electromagnetic coil surrounding a waveguide using the CMOS process flow, supporting nonreciprocal functionality. The coil induces rotation of light modes in the waveguide by generating high magnetic flux density. This serves as a foundational step towards the development of commercially viable on-chip optical isolators.
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
Mingfei Ding, Yiwei Xie, Hao Yan, Abu Naim R. Ahmed, Reza Safian, Swapnajit Chakravarty, Leimeng Zhuang, Pengcheng Jiao, Huan Li, Liu Liu, Daoxin Dai
Summary: All-optical silicon-photonics-based LiDAR systems offer advantages in scanning resolution, speed, size, weight, and cost. This research presents the first experimental verification of all-passive silicon photonics conditional circulators for monostatic LiDAR systems using a nonlinear switch. The proposed silicon nonlinear interferometer is implemented with silicon photonic waveguides and a standard fabrication process, providing flexibility and integration capabilities.
PHOTONICS RESEARCH
(2022)
Article
Optics
Shuyuan Liu, Daiki Minemura, Yuya Shoji
Summary: In this paper, a silicon-based waveguide-integrated polarization-independent magneto-optical isolator is proposed. After processing by a CMOS compatible process on the silicon platform, isolation ratios of 20 dB and 12 dB, as well as insertion losses of 4.6 dB and 8.2 dB, were measured corresponding to TE and TM-polarized input, respectively. This isolator is expected to be employed in polarization multiplexing systems to further increase the integration density.
Article
Engineering, Electrical & Electronic
Xuchen Wang, Sergei A. Tretyakov
Summary: Waveguide characterization is a convenient approach for measuring dielectric constant. This article presents a method to measure arbitrarily shaped dielectric slabs extending outside waveguides by creating a discontinuity between two waveguide flanges. The equivalent shunt impedance of the measured sample is determined by the material permittivity and insensitive to sample shape, position, and sizes. This method is useful for accurate measurements of permittivity in medium-loss and high-loss dielectrics.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2022)
