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Optical Thouless pumping transport and nonlinear switching in a topological low-dimensional discrete nematic liquid crystal array

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Physical Review A 2022年第1期105卷 013513-013513页

作者： Pawel S. Jung Midya Parto Georgios G. Pyrialakos Hadiseh Nasari Katarzyna Rutkowska Marek Trippenbach Mercedeh Khajavikhan Wieslaw Krolikowski Demetrios N. Christodoulides CREOL The College of Optics and Photonics University of Central Florida Orlando Florida 32816 USA Faculty of Physics Warsaw University of Technology Warsaw Poland Ming Hsieh Department of Electrical and Computer Engineering University of Southern California Los Angeles California 90089 USA Faculty of Physics University of Warsaw Warsaw Poland Department of Physics & Astronomy Dornsife College of Letters Arts & Sciences University of Southern California Los Angeles California 90089 USA Laser Physics Centre Research School of Physics Australian National University Canberra ACT 0200 Australia Science Program Texas A&M University at Qatar Doha Qatar

We theoretically investigate a Thouless pumping scheme in the one-dimensional topological Su-Schrieffer-Heeger (SSH) model for single and multiple band-gap systems when implemented in a discrete nematic liquid crystal arrangement. For an electrically controlled SSH waveguide array, we numerically demonstrate edge-to-edge light transport at low power levels. On the other hand, at higher powers, the transport is frustrated by light-induced nonlinear defect states, giving rise to robust all-optical switching.

关键词： Optical solitons Topological insulators Liquid crystals Topological materials

Photonic orbital angular momentum with controllable orientation

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arXiv 2021年

作者： Wan, Chenhao Chen, Jian Chong, Andy Zhan, Qiwen School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai200093 China School of Optical and Electronic Information Huazhong University of Science and Technology Hubei Wuhan430074 China Department of Electro-Optics and Photonics University of Dayton 300 College Park DaytonOH45469 United States Department of Physics University of Dayton 300 College Park DaytonOH45469 United States

Vortices are whirling disturbances commonly found in nature ranging from tremendously small scales in Bose-Einstein condensates to cosmologically colossal scales in spiral galaxies. An optical vortex, generally associated with a spiral phase, can carry orbital angular momentum (OAM). The optical OAM can either be in the longitudinal direction if the spiral phase twists in the spatial domain or in the transverse direction if the phase rotates in the spatiotemporal domain. In this article, we demonstrate the intersection of spatiotemporal vortices and spatial vortices in a wave packet. As a result of this intersection, the wave packet hosts a tilted OAM that provides an additional degree of freedom to the applications that harness the OAM of photons. Copyright © 2021, The Authors. All rights reserved.

关键词： Vortex flow

Experimental demonstration of cylindrical vector spatiotemporal optical vortex

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arXiv 2021年

作者： Chen, Jian Wan, Chenhao Chong, Andy Zhan, Qiwen School of Optical‐Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai200093 China School of Optical and Electronic Information Huazhong University of Science and Technology WuhanHubei430074 China Department of Physics University of Dayton 300 College Park DaytonOH45469 United States Department of Electro‐Optics and Photonics University of Dayton 300 College Park DaytonOH45469 United States

We experimentally generate cylindrically polarized wavepackets with transverse orbital angular momentum, demonstrating the coexistence of spatiotemporal optical vortex with spatial polarization singularity. The results in this paper extend the study of spatiotemporal wavepackets to a broader scope, paving the way for its applications in various areas such as light‐matter interaction, optical tweezers, spatiotemporal spin‐orbit angular momentum coupling, etc. Copyright © 2021, The Authors. All rights reserved.

关键词： Optical tweezers

New Design For Color Screen Sets For High-End Digital Color Press

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New Design For Color Screen Sets For High-End Digital Color ...

IEEE International Conference on Image Processing

作者： Tal Frank Oren Haik Altyngul Jumabayeva Jan P. Allebach Yitzhak Yitzhaky Hewlett-Packard Indigo Ltd. Ness Ziona Rehovot Israel School of Electrical and Computer Engineering Purdue University West Lafayette IN USA Department of Electro-Optics Engineering Ben-Gurion University P.O. Box 653 Beer Sheva Israel

ISBN: (数字)9781728163956

ISBN: (纸本)9781728163963

Digital halftoning is an essential part of the process for printing color, continuous-tone content. Traditionally, the highest quality has been achieved with analog, offset lithographic presses, using color screen sets that yield periodic, clustered-dot halftone patterns. Increasingly, these systems are being supplanted by digital presses that are based on either electrophotographic or inkjet marking processes. Due to the inherent instability of the electrophotographic marking process, periodic, clustered-dot halftone patterns are also widely used with such presses. However, digital presses have much lower resolution than their analog counterparts. Simply mimicking the traditional screen designs used with commercial, offset presses will result in halftone patterns that are more susceptible to moire due to the interaction between the periodic patterns used to render the different color channels. The moire can be reduced by increasing the frequency of the halftone patterns. But this may make the print appear grainier than its analog counterpart. In this paper, we introduce a principled design procedure that allows one to design color screen sets that generate periodic, clustered-dot halftone patterns that improve color stability without increasing graininess.

关键词： Microcell networks Image color analysis Presses Geometry Printers Color Laser stability

Chiral phase change nanomaterials

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arXiv 2021年

作者： Burrow, Joshua A. Alam, Md Shah Smith, Evan M. Yahiaoui, Riad Laing, Ryan Shah, Piyush J. Searles, Thomas A. Vangala, Shivashankar Hendrickson, Joshua R. Sarangan, Andrew Agha, Imad Department of Electro-Optics University of Dayton DaytonOH United States Department of Electrical Engineering Brown University ProvidenceRI United States KBR Inc. BeavercreekOH45431 United States Department of Electrical & Computer Engineering University of Illinois Chicago ChicagoIL United States Apex Microdevices LLC West ChesterOH45069 United States Air Force Research Laboratory Sensors Directorate Wright-Patterson AFBOH45433 United States Department of Physics University of Dayton DaytonOH United States Department of Physics Massachusetts Institute of Technology CambridgeMA United States

Chiral nanostructures offer the ability to respond to the vector nature of a light beam at the nanoscale. While naturally chiral materials offer a path towards scalability, engineered structures offer a path to wavelength tunability through geometric manipulation. Neither approach, however, allows for temporal control of chirality. Therefore, in the best of all worlds, it is crucial to realize chiral materials that possess the quality of scalability, tailored wavelength response, and dynamic control at high speeds. Here, a new class of intrinsically chiral phase change nanomaterials (PCNMs) is proposed and explored, based on a scalable bottom-up fabrication technique with a high degree of control in three dimensions. Angular resolved Mueller Matrix and spectroscopic ellipsometry are performed to characterize the optical birefringence and dichroism, and a numerical model is provided to explain the origin of optical activity. This work achieves the critical goal of demonstrating high-speed dynamic switching of chirality over 50,000 cycles via the underlying PCNM. © 2021, CC BY.

关键词： Nanostructured materials

Optical Thouless pumping transport and nonlinear switching in a topological low-dimensional discrete nematic liquid crystal array

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arXiv 2022年

作者： Jung, Pawel S. Parto, Midya Pyrialakos, Georgios G. Nasari, Hadiseh Rutkowska, Katarzyna Trippenbach, Marek Khajavikhan, Mercedeh Krolikowski, Wieslaw Christodoulides, Demetrios N. CREOL The College of Optics and Photonics University of Central Florida OrlandoFL32816 United States Faculty of Physics Warsaw University of Technology Warsaw Poland Ming Hsieh Department of Electrical and Computer Engineering University of Southern California Los AngelesCA90089 United States Faculty of Physics University of Warsaw Warsaw Poland Department of Physics & Astronomy Dornsife College of Letters Arts & Sciences University of Southern California Los AngelesCA90089 United States Laser Physics Centre Research School of Physics and Engineering Australian National University CanberraACT0200 Australia Science Program Texas A&M University at Qatar Doha Qatar

We theoretically investigate a Thouless pumping scheme in the 1D topological Su-Schrieffer-Heeger (SSH) model for single and multiple band-gaps systems when implemented in a discrete nematic liquid crystal arrangement. For an electrically controlled SSH waveguide array, we numerically demonstrate edge-to-edge light transport at low power levels. On the other hand, at higher powers, the transport is frustrated by light-induced nonlinear defect states, giving rise to robust all-optical switching. © 2022, CC BY.

关键词： Nematic liquid crystals

Detection of photonic orbital angular momentum with micro- and nano-optical structures

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Frontiers of Optoelectronics 2019年第1期12卷 88-96页

作者： Chenhao WAN Guanghao RUI Jian CHEN Qiwen ZHAN School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China Department of Electro-Optics and Photonics University of Dayton300 College ParkDaytonOhio 45469USA Advanced Photonics Center Southeast UniversityNanjing 210096JiangsuChina School of Electronic Engineering University of Electronic Science and Technology of ChinaChengdu 611731China School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China

Light with an optical orbital angular momentum(OAM)has attracted an increasing amount of interest and has found its way into many disciplines ranging from optical trapping,edge-enhanced microscopy,high-speed optical communication,and secure quantum teleportation to spin-orbital *** a variety of OAM-involved applications,it is crucial to discern different OAM states with high *** the current paper,we review the latest research progress on OAM detection with micro-and nano-optical structures that are based on plasmonics,photonic integrated circuits(PICs),and liquid crystal *** innovative OAM sorters are promising to ultimately achieve the miniaturization and integration of high-fidelity OAM detectors and inspire numerous applications that harness the intriguing properties of the twisted light.

关键词： orbital angular momentum (OAM) optical vortices singular optics spatial light modulator surface plasmon polariton (SPP) holography photonic integrated circuit (PIC)

Random Distributed Feedback Fiber Laser Generating Cylindrical Vector Beams

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Physical Review Applied 2019年第4期11卷 044051-044051页

作者： Jinghao Wang Ruishan Chen Junna Yao Hai Ming Anting Wang Qiwen Zhan Department of Optics and Optical Engineering University of Science and Technology of China Hefei 230026 Anhui China Department of Electro-Optics and Photonics University of Dayton Dayton Ohio 45469 USA School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology 200093 Shanghai China

We experimentally demonstrate a random distributed feedback fiber laser generating cylindrical vector beams via a mode-selective coupler and a fiber ring resonator with 50-m-long single-mode fiber. Because of random distributed feedback provided by the single-mode fiber, multimode interactions are suppressed in the cavity, leading to modeless output. Azimuthally and radially polarized beams can both be obtained by adjustment of the polarization controllers. Speckle contrast measurements are made to confirm the effectiveness of the designed laser in reducing laser speckle. Apart from the low cost and simple technology of such a laser, the cylindrical vector beams with modeless behavior may have applications in areas such as laser radars, free-space communication, remote sensing, and biomedical imaging.

关键词： Beam optics Brillouin scattering & spectroscopy Integrated optics Photonics Polarization of light Rayleigh scattering Spatial profiles of optical beams Fiber lasers

Fading Analysis of Direct Detection Free Space Optical Systems under Different Atmosphere Conditions

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Fading Analysis of Direct Detection Free Space Optical Syste...

IEEE National Conference on Aerospace and electronics (NAECON)

作者： Elforjani Jera Rajab Ataai Hamid Al-Ghazi Mohammed Saleh Electro-Optics & Photonics Engineering Department University of Dayton Dayton USA Electrical and Computer Engineering Department University of Dayton Dayton USA Mechanical Engineering Department University of Dayton Dayton USA

ISBN: (数字)9781728114163

ISBN: (纸本)9781728114170

Free space optical communication systems have been used in many communication applications and especially the communication through the free medium such as the atmosphere. However, they are still having some performance limitation due to the atmosphere turbulence. In this paper, we will test an important factor that affects the performance of any free space optical communication system, which is fading in the received signal. The signal fading is tested under week to moderate turbulent atmosphere. We will use the conventional Kolmogorov power spectrum model to evaluate a free space optical system when the probability distribution function is characterized by log-normal probability distribution function (PDF). The probability of fade and fading time will be discussed. Also, the acceptable fading threshold is tested for optical system under the given conditions.

关键词： Optical receivers Fading channels Lenses Atmospheric modeling Optical refraction