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A new class of negative refractive index transmission line

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第8期8卷 1179-1182页

作者： HU Xin he sailing Center for Optical ＆ Electromagnetic Research Zhejiang University Hangzhou 310058 China Division of Electromagnetic Engineering School of Electrical Engineering Royal Institute of Technology S-100 44 Stockholm Sweden

We propose a new class of negative refractive index transmission line in which ideal operational amplifiers are applied to form the periodically loaded negative-impedance-converted inductors and capacitors. The phase response of the new trans-mission line is opposite to that of a positive refractive index conventional transmission line. Unlike the existing negative refractive index transmission line,the new negative refractive index transmission line is non-dispersive and thus can lead to many novel applications such as designing new broadband devices.

关键词： Negative refractive index (NRI) Transmission line (TL) Negative-impedance-converted Non-dispersive

Ultra-stable near-infrared Tm^(3+)-doped upconversion nanoparticles for in vivo wide-field two-photon angiography with a low excitation intensity

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Journal of Innovative Optical health Sciences 2019年第3期12卷 67-77页

作者： Wen Liu Runze Chen sailing he State Key Laboratory of Modern Optical Instrumentations Centre for Optical and Electromagnetic Research Zhejiang University Hangzhou 310058P.R.China School of Electrical Engineering Royal Institute of Technology Stockholm SE-10044 Sweden

Two-photon luminescence with near-infrared(NIR)excitation of upconversion nanoparticles(NPs)is of great importance in biological imaging due to deep penetration in high-scattering tissues,low auto-luminescence and good sectioning ***,common two-photon luminescence is in visible band with an extremely high exciation power density,which limits its ***,we synthesized NaYF_(4):Yb/Tm@NaYF_(4)upconversion NPs with strong twophoton NIR emission and a low excitation power ***,NaYF_(4):Yb/Tm@NaYF_(4)@SiO_(2)@OTMS@F127 NPs with high chemical stability were obtained by a modified multilayer coating method which was applied to upconversion NPs for thefirst *** addition,it is shown that the as-prepared hydrophillic upconversion NPs have great biocompatibility and kept stable for 6 hours during in vivo whole-body *** vessels with two-photon luminescence were clear even under an excitation power density as low as 25mW/cm^(2).Vivid visualizations of capillaries and vessels in a mouse brain were also obtained with low background and high *** of cheaper instruments and safer power density,the NIR two-photon luminescence of NaYF_(4):Yb/Tm@NaYF_(4)upconversion NPs could promote wider application of two-photon *** modified multilayer coating method could be widely used for upconversion NPs to increase the stable time of the in vivo *** work possesses a great potential for deep imaging and imaging-guided treatment in the future.

关键词： Ultra-stable upconversion nanoparticles two-photon luminescence in vivo brain angiography low excitation power density

Science Letters:Dual structure of composite right/left-handed transmission line

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第10期7卷 1777-1780页

作者： HU Xin ZHANG Pu he sailing Center for Optical and Electromagnetzc Research Zhejiang University Hangzhou 3 10058 China Division of Electromagnetic Engineering School of Electrical Engineering Royal Institute of Technology S-100 44 Stockholm Sweden

A dual structure of composite right/left handed (CRLH) transmission line (TL) is analyzed in which an inductance LR is in parallel with a capacitance CL and a shunt capacitance CR is in series with an inductance LL. Both the distributed and lumped cases are considered. The dispersion diagram and transmission properties of the dual CRLH TL are given and compared with those of a standard CRLH TL. Contrary to the frequency response of a standard CRLH TL, a dual CRLH TL has a left-handed (negative phase shift) band at higher frequencies and a right-handed (positive phase shift) band at lower frequencies. A novel dual-band balun is presented as an application.

关键词： Dual structure Composite fight/left handed transmission line (CRLH TL) Dual band balun

Aluminum nanocrystals evolving from cluster to metallic state:Size tunability and spectral evidence

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Nano Research 2022年第2期15卷 838-844页

作者： Hao Wu Xiaoyu Cheng Hongguang Dong Songjun Xie sailing he National Engineering Research Centre for Optical Instruments College of Optical Science and EngineeringZhejiang UniversityHangzhou 310058China Ningbo Research Iristitute Ningbo 315100China

Sub-3 nm aluminum(Al)nanocrystal is an emerging class of nanomaterial with properties distinct to noble metal *** complete solution synthesis of aluminum nanoclusters was recently reported,and their photoluminescence(PL)was observed for the first *** the moment,there exists no method to tune the size of ultrasmall aluminum nanocrystals in solution thus no knowledge on the boundary state between aluminum nanoclusters to plasmonic *** this work,it is demonstrated a study of size-controlled solution synthesis of ultrasmall aluminum nanocrystals with size controlled between -2.2 and -3.8 *** the size results in three sets of spectral responses:(1)absorption due to nascent plasmons generated at -340 nm for larger particles,confirmed by Mie theory calculations;(2)significant decreased quantum yield of PL from -7.8%to -2.4%,indicating reduced quantum confinement effects and increased metallicity;(3)drop of fluorescence lifetime was observed,especially when the diameter of aluminum nanoparticles was changed from -3.0 to -3.8 *** study provides experimental evidence and insights to the transitional state between aluminum nanoclusters and plasmonic nanoparticles,which seems to occur at size larger than gold nanoclusters.

关键词： aluminum nanocrystals plasmon nanoclustors photoluminescence

A new broadband differential phase shifter fabricated using a novel CRLH structure

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第10期8卷 1568-1572页

作者： ZOU Yong-zhuo LIN Zhi-li LING Ti YAO Jun he sailing state Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027. China Division of Electromagnetic Theory Alfven Laboratory Royal Institute of Technology S-I00 44 Stockholm Sweden

Broadband phase shifters are mostly proposed and fabricated based on the scheme proposed by Shiffman, which uses a coupled line with far ends connected together and a uniform transmission line to give a differential phase shift. Based on the unique dispersion property of the composite right/left-handed (CRLH) metamaterial structure, a new configuration is presented in this paper for fabricating the broadband differential phase shifter, which employs a novel CRLH metamaterial structure as one of the differential phase-shift arms, instead of the conventional coupled line. The new circuit can achieve a phase shift of 90° in an operational bandwidth as broad as one octave and its phase deviations are quite small. An original design of the novel broadband phase shifter is presented, in which the artificial CRLH structure was implemented by microstrip quasi-lumped elements. Both the simulated and measured results of the 90° broadband differential phase shifter are presented.

关键词： Broadband Differential phase shifter Composite right/left-handed (CRLH) metamaterial structure Quasi-lumpedelements

Multilayered polyelectrolyte-coated gold nanorods as multifunctional optical contrast agents for cancer cell imaging

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第6期11卷 417-422页

作者： Li-li CheN Li JIANG Ya-lun WANG Jun QIAN sailing he Centre for Optical and Electromagnetic Research State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310058 China Department of Electromagnetic Engineering School of Electrical Engineering Royal Institute of Technology S-100 44 Stockholm Sweden

We report the application of multilayered polyelectrolyte-coated gold nanorods(GNRs) as multifunctional optical contrast agents for cancer cell *** surface modification of GNRs improves their chemical stability and facilitates them to be taken up by cancer cells through electrostatic *** unique longitudinal surface plasmon resonance property of GNRs makes them suitable as both "scattering contrast agents" and "Raman contrast agents".In our experiments,the staining of GNRs in cells was further confirmed by dark field microscopy and Raman *** experiment results indicated that GNRs have great potential as multifunctional "optical contrast agents" for future in vivo animal imaging.

关键词： Gold nanorods Polyelectrolyte Scattering Raman Cancer cell imaging

Turning a hot spot into a cold spot:polarization-controlled Fano-shaped local-field responses probed by a quantum dot

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Light(Science & Applications) 2020年第1期9卷 417-428页

作者： Juan Xia Jianwei Tang Fanglin Bao Yongcheng Sun Maodong Fang Guanjun Cao Julian Evans sailing he Centre for Optical and Electromagnetic Research State Key Laboratory of Modern Optical InstrumentationNational Engineering Research Center for Optical InstrumentationJORCEPCollege of Optical Science and EngineeringZhejiang University310058 HangzhouChina School of Physics Huazhong University of Science and Technology430074 WuhanChina Centre for Optical and Electromagnetic Research ZJU-SCNU Joint Center of PhotonicsSouth China Academy of Advanced OptoelectronicsSouth China Normal University510006 GuangzhouChina Department of Electromagnetic Engineering School of Electrical EngineeringRoyal Institute of TechnologyS-10044 StockholmSweden

Optical nanoantennas can convert propagating light to local *** local-field responses can be engineered to exhibit nontrivial features in spatial,spectral and temporal domains,where local-field interferences play a key ***,we design nearly fully controllable local-field interferences in the nanogap of a nanoantenna,and experimentally demonstrate that in the nanogap,the spectral dispersion of the local-field response can exhibit tuneable Fano lineshapes with nearly vanishing Fano dips.A single quantum dot is precisely positioned in the nanogap to probe the spectral dispersions of the local-field *** controlling the excitation polarization,the asymmetry parameter q of the probed Fano lineshapes can be tuned from negative to positive values,and correspondingly,the Fano dips can be tuned across a broad spectral ***,at the Fano dips,the local-field intensity is strongly suppressed by up to ~50-fold,implying that the hot spot in the nanogap can be turned into a cold *** results may inspire diverse designs of local-field responses with novel spatial distributions,spectral dispersions and temporal dynamics,and expand the available toolbox for nanoscopy,spectroscopy,nano-optical quantum control and nanolithography.

关键词： quantum local dispersion

Targeted and imaging-guided in vivo photodynamic therapy for tumors using dual-function, aggregation- induced emission nanoparticles

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Nano Research 2018年第5期11卷 2756-2770页

作者： Xianhe Sun Abudureheman Zebibula Xiaobiao Dong Gonghui Li Guanxin Zhang Deqing Zhang Jun Qian sailing he State Key Laboratory of Modern Optical Instrumentations Centre for Optical and Electromagnetic Research Zhejiang University Hangzhou 310058 China Department of Urology Sir Run Run Shaw Hospital College of Medicine Zhejiang University Hangzhou 310016 China Beijing National Laboratory for Molecular Sciences CAS Key Laboratories of Organic Solids and Analytical Chemistry for Living Biosystems Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China School of Electrical Engineering Royal Institute of Technology OSQULDAS VAG 6 Stockholm SE-10044 Sweden

Imaging-guided photodynamic therapy （PDT） has been regarded as a promising strategy for precise cancer treatment. Because of their excellent modifiability and drug-loading capacity, nanoparticles have played an important role in PDT. Nonetheless, when traditional photosensitizers are made into nanoparticles, both their fluorescence and reactive oxygen species generation efficacy decrease due to a phenomenon known as aggregation-caused quenching. Fortunately, in recent years, several kinds of organic dyes with ＂abnormal＂ properties （termed aggregation-induced emission, AIE） were developed. With enhanced fluorescence emission in the nanoaggregation state, the traditional obstacles mentioned above may be overcome by AIE luminogens. herein, we provide a better combination of photosensitizers and nanoparticles, namely, dual-function AIE nanopartides capable of producing reactive oxygen species, to implement targeted and imaging-guided in vivo PDT. Good contrast of in vivo imaging and obvious therapeutic efficacy were observed at a low dose of AIE nanoparticles and low irradiance of light, thus resulting in negligible side effects. Our work shows that AIE nanopartides may play a promising role in imaging-guided clinical PDT for cancer in the near future.

关键词： aggregation-induced emission targeted therapy imaging-guided therapy photodynamic therapy tumor

Energy intensity analysis of modes in hybrid plasmonic waveguide

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Frontiers of Optoelectronics 2012年第1期5卷 68-72页

作者： Ruixi ZENG Yuan ZHANG sailing he Centre for Optical and Electromagnetic Research State Key Laboratory of Modem Optical InstrumentationsZhejiang UniversityHangzhou 310058China Joint Research Center of Photonics of Zhejiang University and South China Normal University South China Normal UniversityGuangzhou 510006China

A hybrid plasmonic waveguide containing silicon core, silver cap and ultra-thin sandwiched SiO2 layer is studied. By analyzing the mode distribution patterns and the curves of mode effective index, we show how the plasmonic mode around the metal surface is coupled with the fundamental mode in the silicon core to form a squeezed hybrid mode. The ability of the hybrid plasmonic waveguide in energy confinement is also discussed quantitatively.

关键词： plasmonic hybrid plasmonic waveguide,energy intensity integration density