Article
Engineering, Electrical & Electronic
Md Omar Faruk Rasel, Akira Yamauchi, Takaaki Ishigure
Summary: This paper presents a low-loss 3D symmetric crossover multimode optical waveguide realized using the Mosquito method. The crossover structure exhibits minimal excess loss and demonstrates excellent signal transmission performance.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Yohann Franz, Jack Haines, Cosimo Lacava, Massimiliano Guasoni
Summary: In this paper, two strategies for achieving wideband light generation through intermodal nonlinear parametric processes in multimode integrated waveguides are discussed. It is outlined how the interplay among intermodal interactions and high dispersion may lead to the generation of light with substantial power spectral density, with a long-term vision of generating widely tunable radiation with high-power spectral density in a broad portion of the transparency window of silicon.
Article
Polymer Science
Svetislav Savovic, Ana Simovic, Branko Drljaca, Milan S. Kovacevic, Ljubica Kuzmanovic, Alexandar Djordjevich, Konstantinos Aidinis, Rui Min
Summary: Mode coupling in a multimode graded-index microstructured polymer optical fiber (GI mPOF) is investigated using the time-independent power flow equation (TI PFE). By using launch beams with various radial offsets, the transient modal power distribution, the equilibrium mode distribution (EMD) length L-c, and the steady-state distribution (SSD) length z(s) can be calculated. The GI mPOF achieves the EMD at a shorter length L-c compared to conventional GI POF. These findings are important for the application of multimode GI mPOFs in communication and optical fiber sensory systems.
Article
Engineering, Electrical & Electronic
Ying-Gang Nan, Junjun Pan, Fu Liu, Xuehao Hu, Patrice Megret
Summary: In this paper, a simulation method for analyzing the spectral properties of fiber Bragg gratings written in silica-based multimode graded-index fiber is described and compared with experimental spectra. The simulation accurately determines the resonance wavelengths and provides detailed reflection and transmission spectra using coupled-mode theory and modal field equations. The simulation results show good agreement with the experimental data.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Chunlan Liu, Ping Wu, Yong Wei, Bo Li, Yudong Su, Xiaoling Zhao, Rui Wang, Lingling Li
Summary: In this paper, a dual-detection-parameter SPR sensor for micro angle and micro displacement measurement was fabricated using graded index multimode fiber. The sensing properties of the fiber were studied and verified through mathematical modeling and theoretical simulation. The experimental results showed high wavelength sensitivity and light intensity sensitivity for both the micro angle and micro displacement sensors. The dual-detection-parameter fiber SPR sensor is simple, stable, and not easily damaged, making it suitable for various fields of micro angle and micro displacement measurement.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Optics
Yu Yang, Junchi Jia, Mingqing Zuo, Yuyang Gao, Zhangyuan Chen, Yongqi He, Juhao Li
Summary: This paper investigates the problem of mode crosstalk caused by bending multimode waveguides in laser direct writing spatial multiplexer/demultiplexer (MUX/DEMUX), and proposes an optimized design of bending to suppress mode coupling.
OPTICS COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Haitao Zhang, Jiaqi Zu, Xiaozheng Liu, Junyu Chen, Haozhen Xu
Summary: An all-fiber supercontinuum source based on graded-index multimode fibers has been reported, achieving high-power output of supercontinuum light.
APPLIED SCIENCES-BASEL
(2022)
Article
Optics
Pilar Pujol-Closa, Jordi Gomis-Bresco, Samyobrata Mukherjee, J. Sebastian Gomez-Diaz, Lluis Torner, David Artigas
Summary: In symmetric planar structures with type II films, slow light in hyperbolic waveguides is associated with topological transitions in the dispersion diagram as film thickness changes, mediated by the coalescence of elliptical mode branches and anomalously ordered hyperbolic mode branches. This transition leads to the formation of a saddle point that transforms into a branch point with slow light characteristics and the appearance of ghost waves for a broad range of film thicknesses.
Article
Physics, Applied
Amirreza Mahigir, Georgios Veronis
Summary: This study introduces wavelength-scale light coupling structures and switches for plasmonic coaxial waveguides. By optimizing single-slit, double-slit, and triple-slit structures, the coupling efficiency is enhanced, and different propagation modes can be generated. Additionally, the study explores outcoupling structures for light extraction and utilizing proper angle excitation for specific modes in plasmonic coaxial waveguides.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Optics
Oleg S. Sidelnikov, Evgeny Podivilov, Mikhail P. Fedoruk, Alexey G. Kuznetsov, Stefan Wabnitz, Sergey A. Babin
Summary: We present a comprehensive theory for describing the experimental beam profiles from multimode fiber Raman lasers. The theory takes into account random linear mode coupling, Kerr beam self-cleaning, and intra-cavity spatial filtering, which are all decisive factors in shaping the Stokes beam with a predominant fundamental mode content.
Article
Optics
Ana Simovic, Alexandar Djordjevich, Branko Drljaca, Svetislav Savovic
Summary: A method for investigating transmission along a multimode W-type GI POF with graded index core is proposed in the study. The numerical solution of power flow equation was used to determine the transmission characteristics of the proposed fiber. Results showed that the equilibrium mode distribution coupling length in W-type GI POF is shorter than in original SC GI POF, leading to wider bandwidth and better performance with thinner and shallower intermediate layers.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Automation & Control Systems
Xiangrui Zhang, Chunyue Song, Jun Zhao, Xiaogang Deng
Summary: This article proposes a robust domain adaptation method to mitigate the negative effect of sensor degradation on soft sensor modeling. By decomposing industrial data into Gaussian domains, a domain discrepancy indicator is designed for domain adaptation and process mode recognition. Furthermore, a domain mapping is applied to correct the drifted online input data, enhancing the robustness of the soft sensor.
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS
(2022)
Article
Optics
Ting Zhang, Wei Zhang, Xiaohong Hu, Ran Pan, Zhenguang Wang, Hushan Wang, Yishan Wang
Summary: This study presents an all fiber spectrally flat supercontinuum source and reveals nonlinear phenomena in the generation of supercontinuum by investigating the evolution of output power.
LASER PHYSICS LETTERS
(2022)
Article
Optics
A. Bendahmane, M. Conforti, O. Vanvincq, C. Mas Arabi, A. Mussot, A. Kudlinski
Summary: The study demonstrates that geometric parametric instability (GPI) in graded-index multimode fibers is significantly affected by higher-order dispersion. By measuring output spectra for different core radii and using phase-matching arguments and numerical simulations, the peaks generated by GPI are distinguished from other coexisting parametric processes. Furthermore, a non-degenerate GPI process involving two pumps at different wavelengths is highlighted for the first time.
Article
Optics
Ting Zhang, Xiaohong Hu, Ran Pan, Zhenguang Wang, Wei Zhang, Yashuai Guo, Ye Feng, Yishan Wang, Wei Zhao
Summary: We demonstrated a more than 30 W all-fiber supercontinuum source by pumping a four-mode graded-index multimode fiber (GIMF) with around 5 picoseconds laser pulse. The discrete spectral peaks in the range of 350-700 nm were found to be generated by the geometric parametric instability effect and quasi-phase matched harmonic generation, while the spectral broadening from 700 nm to 1750 nm (and even to 2400 nm) was caused by the radiation of dispersive waves, stimulated Raman scattering, and the effects of optical soliton. Furthermore, an experimental comparison between the four-mode GIMF and the 50/125 standard GIMF showed that the wavelengths radiated by the parametric instability differed due to different dispersion values, and the supercontinuum generated by the four-mode GIMF had a flatter spectral profile and a wider wavelength range.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Ophthalmology
Milica A. Margeta, Kitiya Ratanawongphaibul, Edem Tsikata, Michele Zemplenyi, Courtney L. Ondeck, Janice Kim, Anne L. Coleman, Fei Yu, Johannes F. de Boer, Teresa C. Chen
Summary: The presence of optic disc hemorrhages in open-angle glaucoma patients was associated with localized neuroretinal rim thickness progression, but not with other progression parameters. Glaucoma progression detected through high-density 3D SD-OCT measurements often preceded the occurrence of DH, indicating that DHs are indicators of ongoing glaucoma progression rather than discrete events causing subsequent progression.
AMERICAN JOURNAL OF OPHTHALMOLOGY
(2022)
Article
Biochemical Research Methods
Tomas Pikalek, Miroslav Stiburek, Stephen Simpson, Tomas Cizmar, Johanna Tragardh
Summary: Multimode fibres have potential as miniature endoscopes for deep tissue imaging. Using a composite probe consisting of a GRIN fibre and a spliced on step-index fibre reduces the intensity of the non-linear background signal.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Optics
Petr Jakl, Martin Siler, Jan Jezek, Angel Cifuentes, Johanna Tragardh, Pavel Zemanek, Tomas Cizmar
Summary: This paper demonstrates that combining a relatively small number of transmission matrices (TMs), measured using different internal references, can completely eliminate blind spots in multimode fiber-based endoscopic imaging, resulting in a significant enhancement of imaging quality.
Article
Optics
Loes Ettema, Benjamin Lochocki, Jeroen J. M. Hoozemans, Johannes F. de Boer, Freek Ariese
Summary: This study presents a combination of label-free and non-invasive techniques to study the biomolecular composition of Alzheimer's disease (AD) human brain tissue. The results show the presence of autofluorescent carotenoids in the plaques and confirm it using Raman microscopy. The researchers also used stimulated Raman scattering (SRS) microscopy to investigate the shift of the beta-sheet Amide I peak in plaques.
Article
Multidisciplinary Sciences
Qiao Chen, Simon A. R. Horsley, Nelson J. G. Fonseca, Tomas Tyc, Oscar Quevedo-Teruel
Summary: This translated article introduces the composition of a double-layer lens and the derived rotationally symmetric inhomogeneous index profiles and geodesic lens shapes by solving an inverse problem. It also proposes a practical implementation of a low-profile antenna and validates its performance in the millimeter wave band.
NATURE COMMUNICATIONS
(2022)
Article
Neurosciences
Ahmed S. Abdelfattah, Sapna Ahuja, Taner Akkin, Srinivasa Rao Allu, Joshua Brake, David A. Boas, Erin M. Buckley, Robert E. Campbell, Anderson Chen, Xiaojun Cheng, Tomas Cizmar, Irene Costantini, Massimo De Vittorio, Anna Devor, Patrick R. Doran, Mirna El Khatib, Valentina Emiliani, Natalie Fomin-Thunemann, Yeshaiahu Fainman, Tomas Fernandez-Alfonso, Christopher G. L. Ferri, Ariel Gilad, Xue Han, Andrew Harris, Elizabeth M. C. Hillman, Ute Hochgeschwender, Matthew G. Holt, Na Ji, Kivilcim Kilic, Evelyn M. R. Lake, Lei Li, Tianqi Li, Philipp Machler, Evan W. Miller, Rickson C. Mesquita, K. M. Naga Srinivas Nadella, U. Valentin Nagerl, Yusuke Nasu, Axel Nimmerjahn, Petra Ondrackova, Francesco S. Pavone, Citlali Perez Campos, Darcy S. Peterka, Filippo Pisano, Ferruccio Pisanello, Francesca Puppo, Bernardo L. Sabatini, Sanaz Sadegh, Sava Sakadzic, Shy Shoham, Sanaya N. Shroff, R. Angus Silver, Ruth R. Sims, Spencer L. Smith, Vivek J. Srinivasan, Martin Thunemann, Lei Tian, Lin Tian, Thomas Troxler, Antoine Valera, Alipasha Vaziri, Sergei A. Vinogradov, Flavia Vitale, Lihong Wang, Hana Uhlirova, Chris Xu, Changhuei Yang, Mu-Han Yang, Gary Yellen, Ofer Yizhar, Yongxin Zhao
Summary: This article reviews a diverse toolkit of novel methods for exploring brain function that have emerged from the BRAIN Initiative and related large-scale efforts, with a focus on neurophotonic tools applicable to animal studies. It provides an outlook for future directions in the field.
Article
Optics
Sylvain Gigan, Ori Katz, Hilton B. de Aguiar, Esben Ravn Andresen, Alexandre Aubry, Jacopo Bertolotti, Emmanuel Bossy, Dorian Bouchet, Joshua Brake, Sophie Brasselet, Yaron Bromberg, Hui Cao, Thomas Chaigne, Zhongtao Cheng, Wonshik Choi, Tomas Cizmar, Meng Cui, Vincent R. Curtis, Hugo Defienne, Matthias Hofer, Ryoichi Horisaki, Roarke Horstmeyer, Na Ji, Aaron K. LaViolette, Jerome Mertz, Christophe Moser, Allard P. Mosk, Nicolas C. Pegard, Rafael Piestun, Sebastien Popoff, David B. Phillips, Demetri Psaltis, Babak Rahmani, Herve Rigneault, Stefan Rotter, Lei Tian, Ivo M. Vellekoop, Laura Waller, Lihong Wang, Timothy Weber, Sheng Xiao, Chris Xu, Alexey Yamilov, Changhuei Yang, Hasan Yilmaz
Summary: In the last decade, various tools such as wavefront shaping and computational methods have been developed to understand and control the propagation of light in complex mediums. This field has revolutionized the possibility of diffraction-limited imaging at depth in tissues, and a vibrant community is actively working on it.
JOURNAL OF PHYSICS-PHOTONICS
(2022)
Article
Multidisciplinary Sciences
Miroslav Stiburek, Petra Ondrackova, Tereza Tuckova, Sergey Turtaev, Martin Siler, Tomas Pikalek, Petr Jakl, Andre Gomes, Jana Krejci, Petra Kolbabkova, Hana Uhlirova, Tomas Cizmar
Summary: Controlled light transport through multimode fibres is a less traumatic approach to study deep brain structures using in-vivo imaging. The authors present a hair-thin endoscope that enables detailed view of the whole depth of the living animal brain. The instrument allows for multi-wavelength detection and random access options, with high lateral resolution. It can be used for observing neurons, their processes, blood vessels, calcium signaling, and blood flow velocity in individual vessels.
NATURE COMMUNICATIONS
(2023)
Review
Optics
Hui Cao, Tomas Cizmar, Sergey Turtaev, Tomas Tyc, Stefan Rotter
Summary: Light transport in a highly multimode fiber is complex and can be controlled using spatial wavefront shaping techniques. These techniques enable precise characterization of field propagation and tailor the transmitted light's spatial pattern, temporal profile, and polarization state. Multimode fibers find applications in imaging, endoscopy, optical trapping, and microfabrication. The output speckle pattern from a multimode fiber encodes information about the input light, allowing it to be retrieved from spatial measurements only. This article provides an overview of recent advances and breakthroughs in controlling light propagation in multimode fibers and discusses emerging applications.
ADVANCES IN OPTICS AND PHOTONICS
(2023)
Proceedings Paper
Engineering, Biomedical
David B. Phillips, Shuhui Li, Une G. Butaite, Hlib Kupianskyi, Simon A. R. Horsley, Tomas Cizmar
Summary: Hair-thin strands of multimode optical fibre (MMF) can be used as endoscopes to capture subcellular resolution images from deep inside the body. However, the images transmitted through MMFs are distorted and unrecognizable. This study presents two new methods to recover the images by calibrating the fibre's input end and designing an optical inverter to unscramble all modes simultaneously.
ADAPTIVE OPTICS AND WAVEFRONT CONTROL FOR BIOLOGICAL SYSTEMS IX
(2023)
Correction
Computer Science, Information Systems
Petr Kadera, Jesus Sanchez-Pastor, Hossein Eskandari, Tomas Tyc, Masoud Sakaki, Martin Schuessler, Rolf Jakoby, Niels Benson, Alejandro Jimenez-Saez, Jaroslav Lacik
Proceedings Paper
Optics
Miroslav Stiburek, Petr Jakl, Tomas Pikalek, Petra Ondrackova, Tomas Cizmar
Summary: Multiphoton microscopy allows tissue imaging with sub-cellular resolution at depths up to 1.5 mm. Optical relay elements called endoscopes are used to deliver light beyond this range. Minimally invasive endoscopy is achieved by focusing light through a step-index multimode optical fibre (MMF) using wave-front control. Fibre micro-endoscopes enable reaching any depth with minimal tissue disruption and maintaining resolution below 1 micron for in vivo microscopy. This study focuses on the impact of manufacturing methods on imaging quality of a custom-terminated multimode fibre probe.
22ND POLISH-SLOVAK-CZECH OPTICAL CONFERENCE ON WAVE AND QUANTUM ASPECTS OF CONTEMPORARY OPTICS
(2022)
Proceedings Paper
Instruments & Instrumentation
Daan Stellinga, David B. Phillips, Simon Peter Mekhail, Adam Selyem, Sergey Turtaev, Tomas Cizmar, Miles J. Padgett
Summary: Endoscopes and similar instruments use bundles of optical fibers to relay each pixel of an image. However, modal dispersion can scramble the image. By treating the fiber as a complex aberration and applying corrective beam shaping, an image can be relayed along the fiber length. By beam-shaping a pulsed laser, a scanning spot can be produced at the distil end of the fiber, and 3D imaging can be achieved by measuring the time dependent intensity of the back-scattered light.
OPTICAL AND QUANTUM SENSING AND PRECISION METROLOGY II
(2022)
Article
Engineering, Electrical & Electronic
Theodorus T. M. van Schaijk, Christos Messinis, Nitesh Pandey, Armand Koolen, Stefan Witte, Johannes F. de Boer, Arie den Boef
Summary: This study developed an overlay sensor based on digital holographic microscopy that can perform overlay measurements at infrared wavelengths while maintaining functionality at visible wavelengths. The experiments demonstrated good linearity and sensitivity to structures at the top of the wafer. The results show the feasibility of a visible and infrared light-sensitive overlay sensor for integrated circuit material selection.
JOURNAL OF MICRO-NANOPATTERNING MATERIALS AND METROLOGY-JM3
(2022)
Article
Computer Science, Information Systems
Petr Kadera, Jesus Sanchez-Pastor, Hossein Eskandari, Tomas Tyc, Masoud Sakaki, Martin Schusler, Rolf Jakoby, Niels Benson, Alejandro Jimenez-Saez, Jaroslav Lacik
Summary: This paper introduces a three-dimensional retroreflective flattened Luneburg lens based on quasi-conformal transformation optics for wide-angle millimeter-wave radio-frequency indoor localization. The lens is fabricated in alumina through lithography-based ceramic manufacturing process, showing high gain and beam steering angle.
