Energy-efficient electro-optic modulators are at the heart of short-reach optical interconnects,and silicon photonics is considered the leading technology for realizing such devices.However,the performance of all-sili...Energy-efficient electro-optic modulators are at the heart of short-reach optical interconnects,and silicon photonics is considered the leading technology for realizing such devices.However,the performance of all-silicon devices is limited by intrinsic material properties.In particular,the absence of linear electro-optic effects in silicon renders the integration of energy-efficient photonic–electronic interfaces challenging.Silicon–organic hybrid(SOH)integration can overcome these limitations by combining nanophotonic silicon waveguides with organic cladding materials,thereby offering the prospect of designing optical properties by molecular engineering.In this paper,we demonstrate an SOH Mach–Zehnder modulator with unprecedented efficiency:the 1-mm-long device consumes only 0.7 fJ bit^(-1) to generate a 12.5 Gbit s^(-1) data stream with a bit-error ratio below the threshold for hard-decision forward-error correction.This power consumption represents the lowest value demonstrated for a non-resonant Mach–Zehnder modulator in any material system.It is enabled by a novel class of organic electro-optic materials that are designed for high chromophore density and enhanced molecular orientation.The device features an electro-optic coefficient of r33<180 pm V^(-1) and can be operated at data rates of up to 40 Gbit s^(-1).展开更多
For our KDP crystal orientation, various tbermo-optic （TO） and relevant temperature-dependence param- eters are defined, presented, and studied in the framework of a transverse and a longitudinal electro-optic （EO...For our KDP crystal orientation, various tbermo-optic （TO） and relevant temperature-dependence param- eters are defined, presented, and studied in the framework of a transverse and a longitudinal electro-optic （EO） modulation systems. This study is based on the concept of the so-called opto-electrical bias （~） ap- plied to the system. For both of the above EO-modulation systems, a set of original equations is extracted and investigated with regard to each of the more important TO or temperature coefficients. Using these equations, for these parameters the role of the transverse configuration is examined in comparison with its corresponding longitudinal configuration. A comparison is done with other orientation of the same KDP crystal.展开更多
[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau...[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau damping,which is particularly important for storage rings operating with ultra-low emittance or atlow beam energy.[Purpose]To further increase the bunch length without additional hardware costs,the phasemodulation in a dual-RF system is considered.[Methods]In this paper,turn-by-turn simulations incorporating randomsynchrotron radiation excitation are conducted,and a brief analysis is presented to explain the bunch lengtheningmechanism.[Results]Simulation results reveal that the peak current can be further reduced,thereby mitigating IBSeffects and enhancing the Touschek lifetime.Although the energy spread increases,which tends to reduce thebrightness of higher-harmonic radiation from the undulator,the brightness of the fundamental harmonic can,in fact,beimproved.展开更多
While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance re...While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.展开更多
Electrosynthesis of hydrogen peroxide through the two-electron oxygen reduction pathway provides a crucial alternative to the energy-intensive anthraquinone process.Nevertheless,the efficicency for hydrogen peroxide g...Electrosynthesis of hydrogen peroxide through the two-electron oxygen reduction pathway provides a crucial alternative to the energy-intensive anthraquinone process.Nevertheless,the efficicency for hydrogen peroxide generation is limited by the competitive four-electron pathway.In this work,we report a noncovalent modulation strategy for the isolated CoN_(4) sites by metal-phthalocyanine molecules confinement,which boosts the two-electron oxygen reduction towards generating hydrogen peroxide.The confined Co-phthalocyanine molecules on CoN_(4) sites through π-π interactions induce the competitive*OOH adsorption between the two Co sites formed nanochannel.This noncovalent modulation contributes to the weakened*OOH binding on CoN_(4) sites and thus suppresses its further dissociation,achieving the maximum selectivity of 95% with high activity for H_(2)O_(2)production.This work shows that tailoring noncovalent interactions beyond the binding sites is a promising approach to modulate the local structure of isolated metal sites and related catalytic performance.展开更多
The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits s...The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits stable bipolar resistive switching characteristic, good retention performance, and reversal characteristic. Under different pulse voltages and light fields, four stable resistance states can also be realized. The analysis shows that the main conduction mechanism of the resistive switching characteristic of the heterojunction is space charge limited current(SCLC) effect. After the comprehensive analysis of the band diagram and the P–E ferroelectric property of the multilayer heterojunction, we can deduce that the SCLC is formed by the effect of the oxygen vacancy which is controlled by ferroelectric polarizationmodulated change of interfacial barrier. And the effective photo-generated carrier also plays a regulatory role in resistance state(RS), which is formed by the double ferroelectric layer Ba TiO3/BiFeO3 under different light fields. This research is of potential application values for developing the multi-state non-volatile resistance random access memory(RRAM) devices based on ferroelectric materials.展开更多
As the demand for computing power in data centers continues to grow, balancing data transmitting speed and energy efficiency has emerged as a critical challenge. Highbandwidth, low-power interconnection schemes are in...As the demand for computing power in data centers continues to grow, balancing data transmitting speed and energy efficiency has emerged as a critical challenge. Highbandwidth, low-power interconnection schemes are increasingly recognized as core requirements for next-generation intelligent computing center designs^([1, 2]). For short-range optical interconnections of intra-chip and inter-chip—typically covering tens of meters or less—microring resonant modulators (MRM) are emerging as an ideal solution.展开更多
lectro-optic modulators are key components in data communication,microwave photonics,and quantum photonics.Modulation bandwidth,energy efficiency,and device dimension are crucial metrics of modulators.Here,we provide ...lectro-optic modulators are key components in data communication,microwave photonics,and quantum photonics.Modulation bandwidth,energy efficiency,and device dimension are crucial metrics of modulators.Here,we provide an important direction for the miniaturization of electro-optic modulators by reporting on ultracompact topological modulators.A topological interface state in a one-dimensional lattice is implemented on a thin-film lithium-niobate integrated platform.Due to the strong optical confinement of the interface state and the peaking enhancement of the electro-optic response,a topological cavity with a size of 1.6×140μm^(2)enables a large modulation bandwidth of 104 GHz.The first topological modulator exhibits the most compact device size compared to reported LN modulators with bandwidths above 28 GHz,to the best of our knowledge.100 Gb/s non-return-to-zero and 100 Gb/s four-level pulse amplitude modulation signals are generated.The switching energy is 5.4 fJ/bit,owing to the small electro-optic mode volume and low capacitance.The topological modulator accelerates the response time of topological photonic devices from the microsecond order to the picosecond order and provides an essential foundation for the implementation of large-scale lithium-niobate photonic integrated circuits.展开更多
A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and h...A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and high extinction ratio.An ultra-low V_(pp)and high-modulation-depth indium phosphide-based racetrack microring modulator is demonstrated in this paper.The proposed device mainly comprises one racetrack microring,incorporating a semiconductor amplifier,and coupling with a bus waveguide through a multimode interference coupler.Traveling wave electrodes are employed to supply bidirectional bias ports,terminating with a 50-Ω impedance.The on/off extinction ratio of the microring reaches 43.3 dB due to the delicately tuning of the gain.An 11 mV V_(pp),a maximum 42.5 dB modulation depth and a 6.6 GHz bandwidth are realized,respectively.This proposed microring modulator could enrich the functionalities and designability of the fundamental integrated devices.展开更多
Electro-optic modulators,which convert electrical signals onto the transmission light,are key devices in electro-optic modulating systems.Modulation efficiency is one of the most important parameters of an electro-opt...Electro-optic modulators,which convert electrical signals onto the transmission light,are key devices in electro-optic modulating systems.Modulation efficiency is one of the most important parameters of an electro-optic modulator,which directly determines the footprint and power consumption of the device.Generally,modulation efficiency strongly depends on the electro-optic response of the crystal.The Pb(In_(1/2)Nb_(1/2))O_(3)-Pb(Mg_(1/3)Nb_(2/3))O_(3)-PbTiO_(3)(PIN-PMN-PT)single crystal with giant electro-optic coefficient(λ_(c))and high transparency indicates the potential to achieve greatly enhanced modulation efficiency.In this study,a prototype PIN-PMN-PT phase modulator was fabricated based on a titanium(Ti)in-diffusion waveguide,which is reported for the first time.The influences of titanium in-diffusion on the composition and domain structure of the PIN-PMN-PT single crystal were studied by transmission electron microscopy(TEM)and piezoelectric force microscopy(PFM),respectively.Finally,a half-wave voltage(V_(π))of 2.3 V was obtained using a device with 6-mm-long(L)electrodes.Furthermore,the electro-optic modulation efficiency(V_(π)L)was calculated as 1.38 V-cm,which was approximately one order of magnitude lower than that of commercial lithium niobate(LiNbO_(3),LN)phase modulators.Such enhanced modulation efficiency indicates more compact device and lower power consumption,which is of great significance for electro-optic modulation systems used in micro-fiber gyroscope,integrated photonic devices,etc.展开更多
The modulation depth, defined according to practical modulation results, which changes with the microwave power and its frequency, is significant for systems utilizing the frequency-shift characteristic of the LiNbO3 ...The modulation depth, defined according to practical modulation results, which changes with the microwave power and its frequency, is significant for systems utilizing the frequency-shift characteristic of the LiNbO3 waveguide Electro-Optic Intensity Modulator （EOIM）. By analyzing the impedance mismatch between the microwave source and the EOIM, the effective voltage applied to the RF port of the EOIM is deprived from the microwave power and its frequency. Associating with analyses of the phase velocity mismatch between the microwave and the optical wave, the theoretical modulation depth has been obtained, which is verified by experimental results. We provide a method to choose the appropriate modulation depth to optimize the desired sideband through proper transmission bias for the system based on the frequency-shift characteristic of the EOIM.展开更多
A new spectrum shaping method, based on electro-optic modulation, to alleviate gain narrowing in chirped pulse amplification （CPA） system, is described and numerically simulated. Near-Fourier transform-limited seed ...A new spectrum shaping method, based on electro-optic modulation, to alleviate gain narrowing in chirped pulse amplification （CPA） system, is described and numerically simulated. Near-Fourier transform-limited seed laser pulse is chirped linearly through optical stretcher. Then the chirped laser pulse is coupled into integrated waveguide electro-optic modulator driven by an aperture-coupled-stripline （ACSL） electricalwaveform generator, and the pulse shape and amplitude are shaped in time domain. Because of the direct relationship between frequency interval and time interval of the linearly chirped pulse, the laser pulse spectrum is shaped correspondingly. Spectrum-shaping examples are modeled numerically to determine the spectral resolution of this technique. The phase error introduced in this method is also discussed.展开更多
We propose and analyze a novel Si-based electro-optic modulator with an improved metal-oxide-semiconductor （MOS） capacitor configuration integrated into silicon-on-insulator （SOl）. Three gate-oxide layers embedded...We propose and analyze a novel Si-based electro-optic modulator with an improved metal-oxide-semiconductor （MOS） capacitor configuration integrated into silicon-on-insulator （SOl）. Three gate-oxide layers embedded in the silicon waveguide constitute a triple MOS capacitor structure, which boosts the modulation efficiency compared with a single MOS capacitor. The simulation results demonstrate that the Vπ Lπ product is 2. 4V · cm. The rise time and fall time of the proposed device are calculated to be 80 and 40ps from the transient response curve, respectively,indicating a bandwidth of 8GHz. The phase shift efficiency and bandwidth can be enhanced by rib width scaling.展开更多
A polymer electro optic modulator has been fabricated with the functional layer acting as a kind of corona poled crosslinkable polyurethane. The three optical layers, namely waveguide, photolithography and oxygen are...A polymer electro optic modulator has been fabricated with the functional layer acting as a kind of corona poled crosslinkable polyurethane. The three optical layers, namely waveguide, photolithography and oxygen are fabricated by spin coating. With the Reactive Ion Etching method, the ridge of the waveguide is constructed. With light at 1 31μm being fiber coupled to waveguide, the mode and the modulation properties of these devices are demonstrated in a micron control system.展开更多
Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough industrially relevant ones due to limited unambiguous measuring range and speckle effects.Multiwavelength interfer...Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough industrially relevant ones due to limited unambiguous measuring range and speckle effects.Multiwavelength interferometry addresses these challenges using synthetic wavelengths,enabling a balance between extended measurement range and resolution by combining several synthetic wavelengths.This approach holds immense potential for diverse industrial applications,yet it remains largely untapped due to the lack of suitable light sources.Existing solutions are constrained by limited flexibility in synthetic-wavelength generation and slow switching speeds.We demonstrate a light source for multiwavelength interferometry based on electro-optic single-sideband modulation.It reliably generates synthetic wavelengths with arbitrary values from centimeters to meters and switching time below 30 ms.This breakthrough paves the way for dynamic reconfigurable multiwavelength interferometry capable of adapting to complex surfaces and operating efficiently even outside laboratory settings.These capabilities unlock the full potential of multiwavelength interferometry,offering unprecedented flexibility and speed for industrial and technological applications.展开更多
A Mach-Zehnder(MZ) electro-optic(EO) modulator are real iz ed,with three optical layers as polymer materials.The functional layer is the co rona poled crosslinkable polyurethane.The ridge waveguide is fabricated by us...A Mach-Zehnder(MZ) electro-optic(EO) modulator are real iz ed,with three optical layers as polymer materials.The functional layer is the co rona poled crosslinkable polyurethane.The ridge waveguide is fabricated by using the spin-coating,poling,photolithography and oxygen reactive ion etching(RIE) techniques.The mode and the modulation properties of these devices are demonstra ted in a micron control system,while the light source works at the wavelength of 1 31 or 1 55 micron.展开更多
High performance electro-optic modulator,as the key device of integrated ultra-wideband optical systems,have be-come the focus of research.Meanwhile,the organic-based hybrid electro-optic modulators,which make full us...High performance electro-optic modulator,as the key device of integrated ultra-wideband optical systems,have be-come the focus of research.Meanwhile,the organic-based hybrid electro-optic modulators,which make full use of the advant-ages of organic electro-optic(OEO)materials(e.g.high electro-optic coefficient,fast response speed,high bandwidth,easy pro-cessing/integration and low cost)have attracted considerable attention.In this paper,we introduce a series of high-perform-ance OEO materials that exhibit good properties in electro-optic activity and thermal stability.In addition,the recent progress of organic-based hybrid electro-optic devices is reviewed,including photonic crystal-organic hybrid(PCOH),silicon-organic hy-brid(SOH)and plasmonic-organic hybrid(POH)modulators.A high-performance integrated optical platform based on OEO ma-terials is a promising solution for growing high speeds and low power consumption in compact sizes.展开更多
Thin-film lithium niobate electro-optical modulator will become the key device in the future optical communication,which has the advantages of high modulation rate,low half-wave voltage,large bandwidth,and easy integr...Thin-film lithium niobate electro-optical modulator will become the key device in the future optical communication,which has the advantages of high modulation rate,low half-wave voltage,large bandwidth,and easy integration compared with conventional bulk lithium niobate modulator.However,because the electrode gap of the lithium niobate film modulator is very narrow,when the microwave frequency gets higher,it leads to higher microwave loss,and the electro-optical performance of the modulator will be greatly reduced.Here,we propose a thin film lithium niobate electro-optic modulator with a bimetallic layer electrode structure to achieve microwave loss less than 8 dB/cm in the range of 200 GHz,exhibiting a voltage-length product of 1.1 V·cm and a 3 dB electro-optic bandwidth greater than 160 GHz.High-speed data transmission test has been performed,showing good performance.展开更多
Diatomic metasurfaces designed for interferometric mechanisms possess significant potential for the multidimensional manipulation of electromagnetic waves,including control over amplitude,phase,frequency,and polarizat...Diatomic metasurfaces designed for interferometric mechanisms possess significant potential for the multidimensional manipulation of electromagnetic waves,including control over amplitude,phase,frequency,and polarization.Geometric phase profiles with spin-selective properties are commonly associated with wavefront modulation,allowing the implementation of conjugate strategies within orthogonal circularly polarized channels.Simultaneous control of these characteristics in a single-layered diatomic metasurface will be an apparent technological extension.Here,spin-selective modulation of terahertz(THz)beams is realized by assembling a pair of meta-atoms with birefringent effects.The distinct modulation functions arise from geometric phase profiles characterized by multiple rotational properties,which introduce independent parametric factors that elucidate their physical significance.By arranging the key parameters,the proposed design strategy can be employed to realize independent amplitude and phase manipulation.A series of THz metasurface samples with specific modulation functions are characterized,experimentally demonstrating the accuracy of on-demand manipulation.This research paves the way for all-silicon meta-optics that may have great potential in imaging,sensing and detection.展开更多
基金This work was supported by the European Research Council(ERC Starting Grant‘EnTeraPIC’,number 280145)by the Alfried Krupp von Bohlen und Halbach Foundation,and by the Initiative and Networking Fund of the Helmholtz Association+7 种基金We further acknowledge support by the DFG Center for Functional Nanostructuresby the Karlsruhe International Research School on Teratronics,by the Karlsruhe School of Optics and Photonicsby the Karlsruhe Nano-Micro Facility,by the DFG Major Research Instrumentation Programmeby the EU-FP7 projects PHOXTROT and BigPIPESby Deutsche Forschungsgemeinschaftby the Open Access Publishing Fund of Karlsruhe Institute of TechnologyFurther financial support was obtained from the National Science Foundation(DMR-0905686,DMR-0120967)the Air Force Office of Scientific Research(FA9550-09-1-0682)
文摘Energy-efficient electro-optic modulators are at the heart of short-reach optical interconnects,and silicon photonics is considered the leading technology for realizing such devices.However,the performance of all-silicon devices is limited by intrinsic material properties.In particular,the absence of linear electro-optic effects in silicon renders the integration of energy-efficient photonic–electronic interfaces challenging.Silicon–organic hybrid(SOH)integration can overcome these limitations by combining nanophotonic silicon waveguides with organic cladding materials,thereby offering the prospect of designing optical properties by molecular engineering.In this paper,we demonstrate an SOH Mach–Zehnder modulator with unprecedented efficiency:the 1-mm-long device consumes only 0.7 fJ bit^(-1) to generate a 12.5 Gbit s^(-1) data stream with a bit-error ratio below the threshold for hard-decision forward-error correction.This power consumption represents the lowest value demonstrated for a non-resonant Mach–Zehnder modulator in any material system.It is enabled by a novel class of organic electro-optic materials that are designed for high chromophore density and enhanced molecular orientation.The device features an electro-optic coefficient of r33<180 pm V^(-1) and can be operated at data rates of up to 40 Gbit s^(-1).
文摘For our KDP crystal orientation, various tbermo-optic （TO） and relevant temperature-dependence param- eters are defined, presented, and studied in the framework of a transverse and a longitudinal electro-optic （EO） modulation systems. This study is based on the concept of the so-called opto-electrical bias （~） ap- plied to the system. For both of the above EO-modulation systems, a set of original equations is extracted and investigated with regard to each of the more important TO or temperature coefficients. Using these equations, for these parameters the role of the transverse configuration is examined in comparison with its corresponding longitudinal configuration. A comparison is done with other orientation of the same KDP crystal.
基金National Natural Science Foundation of China(12405168)The Fundamental Research Funds for the Central Universities,China(2024CDJXY004)。
文摘[Background]High harmonic cavities are widely used in electron storage rings to lengthen thebunch,lower the bunch peak current,thereby reducing the IBS effect,enhancing the Touschek lifetime,as well asproviding Landau damping,which is particularly important for storage rings operating with ultra-low emittance or atlow beam energy.[Purpose]To further increase the bunch length without additional hardware costs,the phasemodulation in a dual-RF system is considered.[Methods]In this paper,turn-by-turn simulations incorporating randomsynchrotron radiation excitation are conducted,and a brief analysis is presented to explain the bunch lengtheningmechanism.[Results]Simulation results reveal that the peak current can be further reduced,thereby mitigating IBSeffects and enhancing the Touschek lifetime.Although the energy spread increases,which tends to reduce thebrightness of higher-harmonic radiation from the undulator,the brightness of the fundamental harmonic can,in fact,beimproved.
基金funding from the National Key Research and Development Program of China(No.2018YFE0110000)the National Natural Science Foundation of China(No.11274259,No.11574258)the Science and Technology Commission Foundation of Shanghai(21DZ1205500)in support of the present research.
文摘While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.
基金financially supported by the National Natural Science Foundation of China(No.U21A2077)the Natural Science Foundation of Shandong Province(Nos.ZR2022JQ08 and 2023HWYQ-028)+4 种基金the Taishan Scholar Project Foundation of Shandong Province(Nos.tsqn202211028 and tsqn202306080)the City University of Hong Kong(Nos.9020005,9610663,and 7020103)ITF-RTH-Global STEM Professorship(No.9446008)Hong Kong Branch of National Precious Metals Material Engineering Research Center—ITC FundGeneral Research Fund(No.9043720)from the Research Grants Council of Hong Kong SAR,China.
文摘Electrosynthesis of hydrogen peroxide through the two-electron oxygen reduction pathway provides a crucial alternative to the energy-intensive anthraquinone process.Nevertheless,the efficicency for hydrogen peroxide generation is limited by the competitive four-electron pathway.In this work,we report a noncovalent modulation strategy for the isolated CoN_(4) sites by metal-phthalocyanine molecules confinement,which boosts the two-electron oxygen reduction towards generating hydrogen peroxide.The confined Co-phthalocyanine molecules on CoN_(4) sites through π-π interactions induce the competitive*OOH adsorption between the two Co sites formed nanochannel.This noncovalent modulation contributes to the weakened*OOH binding on CoN_(4) sites and thus suppresses its further dissociation,achieving the maximum selectivity of 95% with high activity for H_(2)O_(2)production.This work shows that tailoring noncovalent interactions beyond the binding sites is a promising approach to modulate the local structure of isolated metal sites and related catalytic performance.
基金Project supported by the Scientific Research Program of Hunan Provincial Education Department,China(Grant No.18C0232)the International Cooperative Extension Program of Changsha University of Science and Technology,China(Grant No.2019IC35)
文摘The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits stable bipolar resistive switching characteristic, good retention performance, and reversal characteristic. Under different pulse voltages and light fields, four stable resistance states can also be realized. The analysis shows that the main conduction mechanism of the resistive switching characteristic of the heterojunction is space charge limited current(SCLC) effect. After the comprehensive analysis of the band diagram and the P–E ferroelectric property of the multilayer heterojunction, we can deduce that the SCLC is formed by the effect of the oxygen vacancy which is controlled by ferroelectric polarizationmodulated change of interfacial barrier. And the effective photo-generated carrier also plays a regulatory role in resistance state(RS), which is formed by the double ferroelectric layer Ba TiO3/BiFeO3 under different light fields. This research is of potential application values for developing the multi-state non-volatile resistance random access memory(RRAM) devices based on ferroelectric materials.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61925505 and 62405070)"Pioneer" and "Leading Goose" R&D Program of Zhejiang Province (Grant No. 2024C01112)National Key Research and Development Program of China (Grant No. 2023YFB2807100)。
文摘As the demand for computing power in data centers continues to grow, balancing data transmitting speed and energy efficiency has emerged as a critical challenge. Highbandwidth, low-power interconnection schemes are increasingly recognized as core requirements for next-generation intelligent computing center designs^([1, 2]). For short-range optical interconnections of intra-chip and inter-chip—typically covering tens of meters or less—microring resonant modulators (MRM) are emerging as an ideal solution.
基金This work was supported in part by the Key Technologies Research and Development Program under Grant 2020YFB2206101the National Natural Science Foundation of China(NSFC)under Grant 62035016/61975115/61835008.
文摘lectro-optic modulators are key components in data communication,microwave photonics,and quantum photonics.Modulation bandwidth,energy efficiency,and device dimension are crucial metrics of modulators.Here,we provide an important direction for the miniaturization of electro-optic modulators by reporting on ultracompact topological modulators.A topological interface state in a one-dimensional lattice is implemented on a thin-film lithium-niobate integrated platform.Due to the strong optical confinement of the interface state and the peaking enhancement of the electro-optic response,a topological cavity with a size of 1.6×140μm^(2)enables a large modulation bandwidth of 104 GHz.The first topological modulator exhibits the most compact device size compared to reported LN modulators with bandwidths above 28 GHz,to the best of our knowledge.100 Gb/s non-return-to-zero and 100 Gb/s four-level pulse amplitude modulation signals are generated.The switching energy is 5.4 fJ/bit,owing to the small electro-optic mode volume and low capacitance.The topological modulator accelerates the response time of topological photonic devices from the microsecond order to the picosecond order and provides an essential foundation for the implementation of large-scale lithium-niobate photonic integrated circuits.
基金supported by the National Natural Science Foundation of China(61535012,61925505)the National Key R&D Program of China(2018YFB2201900)。
文摘A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and high extinction ratio.An ultra-low V_(pp)and high-modulation-depth indium phosphide-based racetrack microring modulator is demonstrated in this paper.The proposed device mainly comprises one racetrack microring,incorporating a semiconductor amplifier,and coupling with a bus waveguide through a multimode interference coupler.Traveling wave electrodes are employed to supply bidirectional bias ports,terminating with a 50-Ω impedance.The on/off extinction ratio of the microring reaches 43.3 dB due to the delicately tuning of the gain.An 11 mV V_(pp),a maximum 42.5 dB modulation depth and a 6.6 GHz bandwidth are realized,respectively.This proposed microring modulator could enrich the functionalities and designability of the fundamental integrated devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.52102143,51772239,62001369,62075088,and 51761145024)Shaanxi Province Project(Grant Nos.2017ktpt-21 and 2018TD-024)Jiangxi Technological Innovation Guidance Science and Technology Plan(Grant No.S20212BDH80017).
文摘Electro-optic modulators,which convert electrical signals onto the transmission light,are key devices in electro-optic modulating systems.Modulation efficiency is one of the most important parameters of an electro-optic modulator,which directly determines the footprint and power consumption of the device.Generally,modulation efficiency strongly depends on the electro-optic response of the crystal.The Pb(In_(1/2)Nb_(1/2))O_(3)-Pb(Mg_(1/3)Nb_(2/3))O_(3)-PbTiO_(3)(PIN-PMN-PT)single crystal with giant electro-optic coefficient(λ_(c))and high transparency indicates the potential to achieve greatly enhanced modulation efficiency.In this study,a prototype PIN-PMN-PT phase modulator was fabricated based on a titanium(Ti)in-diffusion waveguide,which is reported for the first time.The influences of titanium in-diffusion on the composition and domain structure of the PIN-PMN-PT single crystal were studied by transmission electron microscopy(TEM)and piezoelectric force microscopy(PFM),respectively.Finally,a half-wave voltage(V_(π))of 2.3 V was obtained using a device with 6-mm-long(L)electrodes.Furthermore,the electro-optic modulation efficiency(V_(π)L)was calculated as 1.38 V-cm,which was approximately one order of magnitude lower than that of commercial lithium niobate(LiNbO_(3),LN)phase modulators.Such enhanced modulation efficiency indicates more compact device and lower power consumption,which is of great significance for electro-optic modulation systems used in micro-fiber gyroscope,integrated photonic devices,etc.
基金supported by Program for New Century Excellent Talents in University(No.NCET-06-0925)
文摘The modulation depth, defined according to practical modulation results, which changes with the microwave power and its frequency, is significant for systems utilizing the frequency-shift characteristic of the LiNbO3 waveguide Electro-Optic Intensity Modulator （EOIM）. By analyzing the impedance mismatch between the microwave source and the EOIM, the effective voltage applied to the RF port of the EOIM is deprived from the microwave power and its frequency. Associating with analyses of the phase velocity mismatch between the microwave and the optical wave, the theoretical modulation depth has been obtained, which is verified by experimental results. We provide a method to choose the appropriate modulation depth to optimize the desired sideband through proper transmission bias for the system based on the frequency-shift characteristic of the EOIM.
文摘A new spectrum shaping method, based on electro-optic modulation, to alleviate gain narrowing in chirped pulse amplification （CPA） system, is described and numerically simulated. Near-Fourier transform-limited seed laser pulse is chirped linearly through optical stretcher. Then the chirped laser pulse is coupled into integrated waveguide electro-optic modulator driven by an aperture-coupled-stripline （ACSL） electricalwaveform generator, and the pulse shape and amplitude are shaped in time domain. Because of the direct relationship between frequency interval and time interval of the linearly chirped pulse, the laser pulse spectrum is shaped correspondingly. Spectrum-shaping examples are modeled numerically to determine the spectral resolution of this technique. The phase error introduced in this method is also discussed.
文摘We propose and analyze a novel Si-based electro-optic modulator with an improved metal-oxide-semiconductor （MOS） capacitor configuration integrated into silicon-on-insulator （SOl）. Three gate-oxide layers embedded in the silicon waveguide constitute a triple MOS capacitor structure, which boosts the modulation efficiency compared with a single MOS capacitor. The simulation results demonstrate that the Vπ Lπ product is 2. 4V · cm. The rise time and fall time of the proposed device are calculated to be 80 and 40ps from the transient response curve, respectively,indicating a bandwidth of 8GHz. The phase shift efficiency and bandwidth can be enhanced by rib width scaling.
文摘A polymer electro optic modulator has been fabricated with the functional layer acting as a kind of corona poled crosslinkable polyurethane. The three optical layers, namely waveguide, photolithography and oxygen are fabricated by spin coating. With the Reactive Ion Etching method, the ridge of the waveguide is constructed. With light at 1 31μm being fiber coupled to waveguide, the mode and the modulation properties of these devices are demonstrated in a micron control system.
基金supported by the German Federal Ministry of Education and Research,Research Program Quantum Systems(Grant No.13N16774).
文摘Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough industrially relevant ones due to limited unambiguous measuring range and speckle effects.Multiwavelength interferometry addresses these challenges using synthetic wavelengths,enabling a balance between extended measurement range and resolution by combining several synthetic wavelengths.This approach holds immense potential for diverse industrial applications,yet it remains largely untapped due to the lack of suitable light sources.Existing solutions are constrained by limited flexibility in synthetic-wavelength generation and slow switching speeds.We demonstrate a light source for multiwavelength interferometry based on electro-optic single-sideband modulation.It reliably generates synthetic wavelengths with arbitrary values from centimeters to meters and switching time below 30 ms.This breakthrough paves the way for dynamic reconfigurable multiwavelength interferometry capable of adapting to complex surfaces and operating efficiently even outside laboratory settings.These capabilities unlock the full potential of multiwavelength interferometry,offering unprecedented flexibility and speed for industrial and technological applications.
文摘A Mach-Zehnder(MZ) electro-optic(EO) modulator are real iz ed,with three optical layers as polymer materials.The functional layer is the co rona poled crosslinkable polyurethane.The ridge waveguide is fabricated by using the spin-coating,poling,photolithography and oxygen reactive ion etching(RIE) techniques.The mode and the modulation properties of these devices are demonstra ted in a micron control system,while the light source works at the wavelength of 1 31 or 1 55 micron.
基金the National Natural Science Foundation of China(No.62175267)the Beijing Municipal Natural Science Foundation(No.4192061)+1 种基金the Fundamental Research Funds for the Central Universities(2020MDJC13)the Beijing Talents Foundation(2018000021223ZK45)for the financial support.
文摘High performance electro-optic modulator,as the key device of integrated ultra-wideband optical systems,have be-come the focus of research.Meanwhile,the organic-based hybrid electro-optic modulators,which make full use of the advant-ages of organic electro-optic(OEO)materials(e.g.high electro-optic coefficient,fast response speed,high bandwidth,easy pro-cessing/integration and low cost)have attracted considerable attention.In this paper,we introduce a series of high-perform-ance OEO materials that exhibit good properties in electro-optic activity and thermal stability.In addition,the recent progress of organic-based hybrid electro-optic devices is reviewed,including photonic crystal-organic hybrid(PCOH),silicon-organic hy-brid(SOH)and plasmonic-organic hybrid(POH)modulators.A high-performance integrated optical platform based on OEO ma-terials is a promising solution for growing high speeds and low power consumption in compact sizes.
基金supported by the Self-deployment Project of Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZZ104)the Fujian Province STS Project(Nos.2020T3002 and 2022T3012)。
文摘Thin-film lithium niobate electro-optical modulator will become the key device in the future optical communication,which has the advantages of high modulation rate,low half-wave voltage,large bandwidth,and easy integration compared with conventional bulk lithium niobate modulator.However,because the electrode gap of the lithium niobate film modulator is very narrow,when the microwave frequency gets higher,it leads to higher microwave loss,and the electro-optical performance of the modulator will be greatly reduced.Here,we propose a thin film lithium niobate electro-optic modulator with a bimetallic layer electrode structure to achieve microwave loss less than 8 dB/cm in the range of 200 GHz,exhibiting a voltage-length product of 1.1 V·cm and a 3 dB electro-optic bandwidth greater than 160 GHz.High-speed data transmission test has been performed,showing good performance.
基金supports from National Key Research and Development Program of China(2021YFB2800703)Sichuan Province Science and Technology Support Program(25QNJJ2419)+1 种基金National Natural Science Foundation of China(U22A2008,12404484)Laoshan Laboratory Science and Technology Innovation Project(LSKJ202200801).
文摘Diatomic metasurfaces designed for interferometric mechanisms possess significant potential for the multidimensional manipulation of electromagnetic waves,including control over amplitude,phase,frequency,and polarization.Geometric phase profiles with spin-selective properties are commonly associated with wavefront modulation,allowing the implementation of conjugate strategies within orthogonal circularly polarized channels.Simultaneous control of these characteristics in a single-layered diatomic metasurface will be an apparent technological extension.Here,spin-selective modulation of terahertz(THz)beams is realized by assembling a pair of meta-atoms with birefringent effects.The distinct modulation functions arise from geometric phase profiles characterized by multiple rotational properties,which introduce independent parametric factors that elucidate their physical significance.By arranging the key parameters,the proposed design strategy can be employed to realize independent amplitude and phase manipulation.A series of THz metasurface samples with specific modulation functions are characterized,experimentally demonstrating the accuracy of on-demand manipulation.This research paves the way for all-silicon meta-optics that may have great potential in imaging,sensing and detection.
