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Pulse generation with ultra-superluminal pulse propagation in semiconductor heterostructures by superradiant-phase transition enhanced by transient coherent population gratings

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Light(Science & Applications) 2016年第1期5卷 737-743页

作者： Peter P vasil’ev richard v penty Ian H White Centre for Photonic Systems Department of EngineeringUniversity of CambridgeCambridge CB30FAUK Quantum Electronics Division PN Lebedev Physical InstituteMoscow 119991Russia

This paper reports the observation of ultra-superluminal pulse propagation in multiple-contact semiconductor heterostructures in a superradiant emission regime,and shows definitively that it is a different class of emission from conventional spontaneous or stimulated *** population gratings induced in the semiconductor medium under strong electrical pumping have been shown to cause a major decrease of the group refractive index,in the range of 5–40%.This decrease is much greater than that caused by conventional carrier depletion or chirp *** decrease in refractive index in turn causes faster-than-c propagation of femtosecond *** measurement also proves the existence of coherent amplification of electromagnetic pulses in semiconductors at room temperature,the coherence being strongly enhanced by interactions of the light with coherent transient gratings locked to carrier *** pulse-generation technique is anticipated to have great potential in applications where highly coherent femtosecond optical pulses must be generated on demand.

关键词： phase transition population grating superradiance superluminal propagation

Secure optical communication using a quantum alarm

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Light(Science & Applications) 2020年第1期9卷 380-389页

作者： Yupeng Gong Rupesh Kumar Adrian Wonfor Shengjun Ren richard v.penty Ian H.White Centre for Advanced Photonics and Electronics University of Cambridge9 JJ Thomson AveCambridge CB30FAUK Quantum Communications Hub Information CentreDepartment of PhysicsUniversity of YorkYork YO105DDUK University of Bath Claverton DownBath BA27AYUK

Optical fibre networks are advancing rapidly to meet growing traffic *** issues,including attack management,have become increasingly important for optical communication networks because of the vulnerabilities associated with tapping light from optical fibre *** layer security often requires restricting access to channels and periodic inspections of link *** this paper,we report how quantum communication techniques can be utilized to detect a physical layer *** present an efficient method for monitoring the physical layer security of a high-data-rate classical optical communication network using a modulated continuous-variable quantum *** describe the theoretical and experimental underpinnings of this monitoring system and the monitoring accuracy for different monitored *** analyse its performance for both unamplified and amplified optical *** technique represents a novel approach for applying quantum signal processing to practical optical communication networks and compares well with classical monitoring *** conclude by discussing the challenges facing its practical application,its differences with respect to existing quantum key distribution methods,and its usage in future secure optical transport network planning.

关键词： communication quantum networks

Optical DE/MUX Components for Datacomunication Applications

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光学学报 2003年第S1期23卷 617-618页

作者： Ian H White richard v penty Kevin A Williams Chris N Morgan Cambridge University Engineering Department Trumpington Street Cambridge CB2 1PZ UKCambridge University Engineering Department Trumpington Street Cambridge CB2 1PZ UKCambridge University Engineering Department Trumpington Street Cambridge CB2 1PZ UKCambridge University Engineering Department Trumpington Street Cambridge CB2 1PZ UK

This paper reviews the potential for WDM systems to be implemented within datacommunication systems, and indicates future network functions. Spectral and temporal multiplexing functions are reviewed, with particular f... 详细信息

关键词： for be in Optical DE/MUX Components for Datacomunication Applications WDM

Flexible optoelectronic devices based on metal halide perovskites

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Nano Research 2020年第8期13卷 1997-2018页

作者： Hao Chen Hao Wang Jiang Wu Feng Wang Ting Zhang Yafei Wang Detao Liu Shibin Li richard v.penty Ian H.White School of Optoelectronic Information University of Electronic Science and Technology of ChinaChengdu610054China Centre for Advanced Photonics and Electronics University of CambridgeCambridgeCB30FAUK Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu610054China Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials Department of Materials Science and EngineeringPeking UniversityBeijing100871China

The unique physical and chemical properties of metal halide perovskites predestine the devices to achieve high performance in optoelectronic *** the numerous high qualities of perovskites,their different low-temperature synthesis methods and preparation processes make them impressive and popular materials for flexible optoelectronic *** perovskite devices,for instance,solar cells,photodetectors and light-emitting diodes,have been fabricated on flexible substrates and show outstanding flexibility as well as high *** soft wearable electronic systems,mechanical flexibility is the premier *** to common devices based on rigid substrates,flexible perovskite devices are more practical and see widespread applications in energy,detection,display,and other *** review summarizes the recent progress of flexible perovskite solar cells,photodetectors and light-emitting *** design and fabrication of different high-performance flexible perovskite devices are *** low-dimensional perovskite materials and configurations for flexible perovskite devices are *** addition,the limitations and challenges for further application are also briefly discussed.

关键词： perovskite optoelectronic devices flexibility high-performance

Bridging the gap between resonance and adiabaticity:a compact and highly tolerant vertical coupling structure

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Photonics Research 2022年第9期10卷 2081-2090页

作者： CHUNHUI YAO QIXIANG CHENG GüNTHER ROELKENS richard penty Centre for Photonic Systems Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridge CB3 OFAUK Department of Information Technology(INTEC) Photonics Research GroupGhent University-imec9052 Ghent Belgium

We present a compact,highly tolerant vertical coupling structure,which can be a generic design that bridges the gap between conventional resonant couplers and adiabatic couplers for heterogeneously integrated *** show insights on relaxing the coupler alignment tolerance and provide a detailed design *** the use of a multisegmented inverse taper structure,our design allows a certain proportion of the odd supermode to be excited during the coupling process,which simultaneously facilitates high tolerance and *** a total length of 87μm,our coupler is almost threefold shorter than the state-of-the-art alignment-tolerant adiabatic couplers and outperforms them by demonstrating a more than 94%coupling efficiency(forv-on-silicon vertical ***,our design has high tolerance to fabrication-induced structural deformation and ultrabroad *** features make it particularly suitable for building densely integrated III-v-onsilicon photonic circuits with commercially available microtransfer printing assembly *** proposed design can be widely adopted in various integration platforms.

关键词： coupling adiabatic structure

Iterative photonic processor for fast complexvalued matrix inversion

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Photonics Research 2022年第11期10卷 2488-2501页

作者： MINJIA CHEN QIXIANG CHENG MASAFUMI AYATA MARK HOLM richard penty Department of Engineering Centre for Photonic SystemsElectrical Engineering DivisionUniversity of CambridgeCambridge CB30FAUK Huawei Technologies(Sweden)AB 16440 KistaSweden

An N×N iterative photonic processor is proposed for the first time, we believe, for fast computation of complexvalued matrix inversion, a fundamental but computationally expensive linear algebra operation. Compared to traditional digital electronic processing, optical signal processing has a few unparalleled features that could enable higher representational efficiency and faster computing speed. The proposed processor is based on photonic integration platforms–the inclusion of Ⅲ-v gain blocks offers net neutral loss in the phase-sensitive loops. This is essential for the richardson iteration method that is adopted in this paper for complex linear systems. Wavelength multiplexing can be used to significantly improve the processing efficiency, allowing the computation of multiple columns of the inverse matrix using a single processor core. Performances of the key building blocks are modeled and simulated, followed by a system-level analysis, which serves as a guideline for designing an N×N richardson iteration processor. An inversion accuracy of>98%can be predicted for a 64×64 photonic processor with a>80times faster inversion rate than electronic processors. Including the power consumed by both active components and electronic circuits, the power efficiency of the proposed processor is estimated to be over an order of magnitude more energy-efficient than electronic processors. The proposed iterative photonic integrated processor provides a promising solution for future optical signal processing systems.

关键词： valued matrix iteration

Towards 10 Gb/s orthogonal frequency division multiplexing-based visible light communication using a GaN violet micro-LED

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Photonics Research 2017年第2期5卷 35-43页

作者： MOHAMED SUFYAN ISLIM RICARDO X.FERREIRA XIANGYU HE ENYUAN XIE STEFAN vIDEv SHAUN vIOLA SCOTT WATSON NIKOLAOS BAMIEDAKIS richard v.penty IAN H.WHITE ANTHONY E.KELLY ERDAN GU HARALD HAAS MARTIN D.DAWSON Li–Fi R&D Centre the University of Edinburgh Institute for Digital Communications Institute of Photonics Department of Physics University of Strathclyde Institute for Digital Communications Li–Fi R&D Centre the University of Edinburgh School of Engineering University of Glasgow Centre for Advanced Photonics and Electronics Electrical Engineering Division Department of Engineering University of Cambridge

visible light communication(vLC)is a promising solution to the increasing demands for wireless *** nitride micro-sized light emitting diodes(micro-LEDs)are strong candidates for vLC due to their high *** violet micro-LEDs are reported in this work with electrical-to-optical bandwidths up to 655 *** orthogonal frequency division multiplexing-based vLC system with adaptive bit and energy loading is demonstrated,and a data transmission rate of 11.95 Gb/s is achieved with a violet micro-LED,when the nonlinear distortion of the micro-LED is the dominant noise source of the vLC system.A record 7.91 Gb/s data transmission rate is reported below the forward error correction threshold using a single pixel of the segmented array when all the noise sources of the vLC system are present.

关键词： Towards 10 Gb/s orthogonal frequency division multiplexing-based visible light communication using a GaN violet micro-LED vLC OFDM LEDs

Advances in cost-effective integrated spectrometers

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Light(Science & Applications) 2022年第7期11卷 1379-1396页

作者： Ang Li Chunhui Yao Junfei Xia Huijie Wang Qixiang Cheng richard penty Yeshaiahu Fainman Shilong Pan Key Laboratory of Radar Imaging and Microwave Photonics Ministry of EducationNanjing University of Aeronautics and AstronauticsNanjing 210016China Litin Technology XuzhouJiangsuChina Department of Engineering University of Cambridge9 JJ Thomson AvenueCambridge CB30FAUK Colllege of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Electrical and Computer Engineering University of California at San DiegoLa JollaCAUSA

The proliferation of Internet-of-Things has promoted a wide variety of emerging applications that require compact,lightweight,and low-cost optical *** substantial progresses have been made in the miniaturization of spectrometers,most of them are with a major focus on the technical side but tend to feature a lower technology readiness level for *** importantly,in spite of the advancement in miniaturized spectrometers,their performance and the metrics of real-life applications have seldomly been connected but are highly *** review paper shows the market trend for chip-scale spectrometers and analyzes the key metrics that are required to adopt miniaturized spectrometers in real-life *** progress addressing the challenges of miniaturization of spectrometers is summarized,paying a special attention to the CMOS-compatible fabrication platform that shows a clear pathway to massive *** for ways forward are also presented.

关键词： cost summarized spite

Biofabrication of nanocomposite-based scaffolds containing human bone extracellularmatrix for the differentiation of skeletal stem and progenitor cells

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Bio-Design and Manufacturing 2024年第2期7卷 121-136页

作者： Yang-Hee Kim Janos M.Kanczler Stuart Lanham Andrew Rawlings Marta Roldo Gianluca Tozzi Jonathan I.Dawson Gianluca Cidonio richard O.C.Oreffo Faculty of Medicine Bone and Joint Research GroupCentre for Human DevelopmentStem Cells and RegenerationInstitute of Developmental SciencesUniversity of SouthamptonSouthampton SO166YDUK School of Pharmacy and Biomedical Science University of PortsmouthPortsmouth PO12DTUK School of Engineering Faculty of Engineering and ScienceUniversity of GreenwichGreenwich ME44TBUK Center for Life Nano-and Neuro-Science(CLN2S) Italian Institute of Technology00161 RomeItaly

Autograft or metal implants are routinely used in skeletal ***,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering *** use of native human bone tissue for synthesizing a biomimeticmaterial inkfor three-dimensional(3D)bioprintingof skeletal tissueis anattractivestrategyfor ***,human bone extracellular matrix(bone-ECM)offers an exciting potential for the development of an appropriate microenvironment for human bone marrow stromal cells(HBMSCs)to proliferate and differentiate along the osteogenic *** this study,we engineered a novel material ink(LAB)by blending human bone-ECM(B)with nanoclay(L,Laponite®)and alginate(A)polymers using extrusion-based *** inclusion of the nanoﬁller and polymeric material increased the rheology,printability,and drug retention properties and,critically,the preservation of HBMSCs viability upon *** composite of human bone-ECM-based 3D constructs containing vascular endothelial growth factor(vEGF)enhanced vascularization after implantation in an ex vivo chick chorioallantoic membrane(CAM)*** inclusion of bone morphogenetic protein-2(BMP-2)with the HBMSCs further enhanced vascularization and mineralization after only seven *** study demonstrates the synergistic combination of nanoclay with biomimetic materials(alginate and bone-ECM)to support the formation of osteogenic tissue both in vitro and ex vivo and offers a promising novel 3D bioprinting approach to personalized skeletal tissue repair.

关键词： Extracellular matrix Nanoclay Bone 3D bioprinting