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
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
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
We propose and discuss terahertz(THz) electro-optic modulator induced by periodically patterned graphene microcavity. Due to the joint effect of graphene plasmon resonances and Fabry-Perot(F-P) oscillations, plasmon-i...We propose and discuss terahertz(THz) electro-optic modulator induced by periodically patterned graphene microcavity. Due to the joint effect of graphene plasmon resonances and Fabry-Perot(F-P) oscillations, plasmon-induced transparency(PIT) effect is achieved and the operation frequency can be dynamically tuned by graphene Fermi energies and structural parameters. The results reveal that modulation depth(MD) larger than 80% is obtained across a wide frequency range from 4.2 THz to 9.4 THz, and the largest MD and Q factor reaches 95% and 15.8, respectively. In addition, operation frequency range and MD can also be tuned by optimizing the structure parameters. This investigation promises the development of high-performance widely tunable THz modulator in chip integrated photonic circuits.展开更多
Electro-optic(EO) modulator plays a very critical role in the optical communication systems. Here, we report a stimulated thin-film lithium niobate(LN) modulator with a half-wave voltage-length product of 1.8 V·c...Electro-optic(EO) modulator plays a very critical role in the optical communication systems. Here, we report a stimulated thin-film lithium niobate(LN) modulator with a half-wave voltage-length product of 1.8 V·cm, which can successfully achieve modulation and demodulation of a 1 GHz sinusoidal signal with an amplitude of 5 V in experiment. The optical loss caused by metal electrodes is reduced by optimizing the waveguide structure and depositing silica onto the waveguide, and group-velocity matching and characteristic impedance matching are achieved by optimizing the buffer silica layer and the electrode structure for larger bandwidth, which simultaneously improves the modulation efficiency and bandwidth performance. Our work demonstrated here paves a foundation for integrated photonics.展开更多
A quasi-rectangular waveguide polymer MacH^(-)Zehnder (M-Z) electro-optic (EO) modulator based on an organic/inorganic hybrid material with thermal bias control is fabricated and demonstrated.Linear bias for the modul...A quasi-rectangular waveguide polymer MacH^(-)Zehnder (M-Z) electro-optic (EO) modulator based on an organic/inorganic hybrid material with thermal bias control is fabricated and demonstrated.Linear bias for the modulator is obtained through thermo-optic effect.The optical output is adjusted by changing phase difference between the two arms of the M-Z interferometer.A power consumption of 16.1 m W for π phase change is observed owing to the application of silica cladding.This approach is proved to be effective to suppress direct current drift in polymer EO modulators.展开更多
Fabrication and characterization of electro-optic modulators based on the novel organic electro-optic materials composed of self-assembled superlattices (SAS) were presented, both wet-dipping self-assembly and vapor p...Fabrication and characterization of electro-optic modulators based on the novel organic electro-optic materials composed of self-assembled superlattices (SAS) were presented, both wet-dipping self-assembly and vapor phase deposition approaches were discussed. Prototype waveguide electro-optic modulators were fabricated using SAS films integrated with low-loss polymeric materials functioning as partial guiding and cladding layers.Promising electro-optic thin film materials including DTPT and PEPCOOH grown from the vapor phase were used for fabrication and test of electro-optic prototype modulators. Finally,the EO coefficient of tens of pm/V was obtained,which can sufficiently support high-speed and small size EO modulators.展开更多
In this paper, an actively Q-switched wavelength injection locking random fiber laser(RFL) based on random phase-shifted fiber Bragg grating(RPS-FBG) is proposed, and the performance of the laser is verified by experi...In this paper, an actively Q-switched wavelength injection locking random fiber laser(RFL) based on random phase-shifted fiber Bragg grating(RPS-FBG) is proposed, and the performance of the laser is verified by experiments. Within the reflection bandwidth range of RPS-FBG, spanning from 1 549.2 nm to 1 549.9 nm, different laser modes with stable central wavelength and peak power can be selectively chosen by varying the injected light wavelength. The power fluctuation within 1 h is less than 0.1 d Bm, and the central wavelength drift is less than 0.02 nm. When the pump power increases from 90 mW to 300 mW, the pulse width decreases from 3.2 μs to 1.5 μs, and the pulse repetition frequency is 20 kHz. The RFL can reach a stable locking state at the lowest pump power of 100 mW and the lowest injection power of 3 d Bm. When the wavelength is locked, the output pulse is a single pulse. On the contrary, the unlocked output pulse is multi-pulse. The laser has the characteristics of high wavelength tunability in the reflection range of RPS-FBG and it can be an ideal light source in the fields of laser imaging and pulse coding.展开更多
Silicon-based high-speed electro-optical modulator is the key component of silicon photonics for future communiction and interconnection systems. In this paper, introduced are the optical mudulation mechanisms in sili...Silicon-based high-speed electro-optical modulator is the key component of silicon photonics for future communiction and interconnection systems. In this paper, introduced are the optical mudulation mechanisms in silicon, reviewed are some recent progresses in high-speed silicon modulators, and analyzed are advantages and shortages of the silicon modulators of different types.展开更多
Integrated photonics has emerged as a promising alternative for data communication and computing,ferroelectric BaTiO_(3)^(-)(BTO)stands out for its exceptional electro-optic response among candidate materials.However,...Integrated photonics has emerged as a promising alternative for data communication and computing,ferroelectric BaTiO_(3)^(-)(BTO)stands out for its exceptional electro-optic response among candidate materials.However,direct epitaxial growth of BTO entails a fundamental trade-off:substrates with low refractive index are required for strong optical confinement,yet those with large lattice mismatch degrade film crystalline quality and electro-optic performance.We report a buffer-free,strain-engineered approach to integrate high-performance BTO thin films directly on LaAlO3-Sr2TaAlO6(LSAT)oxide-insulator substrates.By exploiting a self-buffer layer formed during the initial growth stage,we achieve periodic in-plane strain modulation that stabilizes a polymorphic phase boundary with orthorhombic polar nanoregions,yielding a Pockels coefficient exceeding 358 pm V^(-1)and a Curie temperature raised to 200℃.Leveraging this material platform,we demonstrate the first realization of a Mach-Zehnder modulator using epitaxial BTO on LSAT.The device exhibits a half-wave voltage-length product of 0.7 V cm at 1550 nm,which closely matches finite-element simulations,and supports a 6-dB electro-optic bandwidth of 28 GHz.Our results validate BTO on LSAT as a viable photonic platform for scalable,low-voltage and high-speed modulators.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
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
High-performance thin film lithium niobate(LN) electro-optic modulators with low cost are in demand. Based on photolithography and wet etching, we experimentally demonstrate a thin film LN Mach–Zehnder modulator with...High-performance thin film lithium niobate(LN) electro-optic modulators with low cost are in demand. Based on photolithography and wet etching, we experimentally demonstrate a thin film LN Mach–Zehnder modulator with a 3 d B bandwidth exceeding 110 GHz, which shows the potential of boosting the throughput and reducing cost. The fabricated modulator also exhibits a comparable low half-wave voltage-length product of ~2.37 V · cm, a high extinction ratio of >23 d B, and the propagation loss of optical waveguides of ~0.2 d B/cm. Besides, six-level pulse amplitude modulation up to 250 Gb/s is successfully achieved.展开更多
In this paper, we theoretically deduce the expressions of half-wave voltage and 3-dB modulation bandwidth in which conductor loss is taken into account. The results suggest that it will affect the theoretical values o...In this paper, we theoretically deduce the expressions of half-wave voltage and 3-dB modulation bandwidth in which conductor loss is taken into account. The results suggest that it will affect the theoretical values of half-wave voltage and bandwidth as well as the optimized electrode's dimension whether considering the conductor loss or not. As an example, we present a Mach-Zehnder (MZ) type polymer waveguide amplitude modulator. The half-wave voltage increases by 1 V and the 3-dB bandwidth decreases by 30% when the conductor loss is taken into account. Besides, the effects of impedance mismatching and velocity mismatching between microwave and light wave on the half-wave voltage, and 3-dB bandwidth are discussed.展开更多
In this paper, a polymer electro-optic mod- ulator has been designed and optimized using the full vectorial finite element method. For this purpose, the effects of magnesium oxide （MgO） and down cladding thicknesses...In this paper, a polymer electro-optic mod- ulator has been designed and optimized using the full vectorial finite element method. For this purpose, the effects of magnesium oxide （MgO） and down cladding thicknesses, distance between two ground electrodes, hot electrode and modulator widths modulator on the key modulator parameters, such as microwave effective index r/m, the characteristic impedance Zc and the microwave losses a are presented. After selecting optimal dimensions of polymer electro-optic modulator, frequency dependent aforementioned parameters and the half-wave voltage- length product （VπL） parameter of polymer electro-optic modulator are extracted and as a consequence, an optimized design is reported. Finally, the optical and electrical modulation responses of polymer electro-optic modulator are calculated. The optimized polymer electro- optic modulator exhibits 3-dB electrical bandwidth of 260 GHz and VπL about 2.8 V- cm in this frequency.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
Using finite element method, lots of calculating focusing on polymer electro-optic modulators with ultra-broadband were done, a few structures were analyzed. Coplanar waveguide electrode system was advanced, a few rea...Using finite element method, lots of calculating focusing on polymer electro-optic modulators with ultra-broadband were done, a few structures were analyzed. Coplanar waveguide electrode system was advanced, a few real examples was given.展开更多
Electro-optic modulator is a key component for on-chip optical signal processing.An electro-optic phase modulator based on multilayer graphene embedded in silicon nitride waveguide is demonstrated to fulfill low-power...Electro-optic modulator is a key component for on-chip optical signal processing.An electro-optic phase modulator based on multilayer graphene embedded in silicon nitride waveguide is demonstrated to fulfill low-power operation.Finite element method is adopted to investigate the interaction enhancement between the graphene flake and the optical mode.The impact of multilayer graphene on the performance of phase modulator is studied comprehensively.Simulation results show that the modulation efficiency improves with the increment of graphene layer number,as well as the modulation length.The 3-dB bandwidth of around 48 GHz is independent of graphene layer number and length.Compared to modulator with two-or four-layer graphene,the six-layer graphene/silicon nitride waveguide modulator can realizeπphase shift at a low-power consumption of 14 fJ/bit when the modulation length is 240μm.展开更多
Broadband,low-drive voltage electro-optic modulators are crucial optoelectronic components in the new-generation microwave photonic links and broadband optical interconnect network applications.In this paper,we fabric...Broadband,low-drive voltage electro-optic modulators are crucial optoelectronic components in the new-generation microwave photonic links and broadband optical interconnect network applications.In this paper,we fabricate a low-loss thinfilm lithium niobate complementary dual-output electro-optic modulator chip with a 3 dB electro-optic bandwidth of 59 GHz and a half-wave voltage(Vπ)of 2.5 V.The insert-loss of the packaged modulator is 4.2 dB after coupling with polarizationmaintaining fiber.The complementary dual-output modulator also shows a common-mode rejection ratio of 18 dB and a signal enhancement of 6.2 dB when adapted in microwave photonic links,comparable to commercial bulk lithium niobate devices.展开更多
Controlling film morphology remains an inherent challenge limiting the performance of all-smallmolecule organic solar cells(ASM-OSCs),primarily due to excessive donor-acceptor compatibility restricting further improve...Controlling film morphology remains an inherent challenge limiting the performance of all-smallmolecule organic solar cells(ASM-OSCs),primarily due to excessive donor-acceptor compatibility restricting further improvements.Here,we introduce a novel strategy employing rhodanine-based film-forming kinetic modulators-specifically tailored for the high-performance donor BTR-Clincluding 3-methylrhodanine(C1),3-ethylrhodanine(C2),3-buty lr hod a nine(C4),and 3-hexylrhodanine(C6).We demonstrate that the C2 modulator uniquely optimizes morphology by extending film-formation time and fine-tuning donor-acceptor miscibility,leading to enhanced molecular ordering,uniform vertical distributio n,and optimal phase sepa ration.This synergistic morphological control significantly boosts BTR-Cl crystallinity and facilitates efficient three-dimensional charge transport networks.Consequently,C2-treated BTR-Cl:N3 ASM-OSCs achieve an outstanding power conversion efficiency(PCE)of 17.12%,ranking among the highest reported for this system.Crucially,this work introduces a novel"donor-modulator structural matching"strategy,providing a powerful new avenue for controlling film-forming kinetics to realize high-performance ASM-OSCs.展开更多
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 Scientific Research Plan Projects of Shaanxi Education Department(203011730)
文摘We propose and discuss terahertz(THz) electro-optic modulator induced by periodically patterned graphene microcavity. Due to the joint effect of graphene plasmon resonances and Fabry-Perot(F-P) oscillations, plasmon-induced transparency(PIT) effect is achieved and the operation frequency can be dynamically tuned by graphene Fermi energies and structural parameters. The results reveal that modulation depth(MD) larger than 80% is obtained across a wide frequency range from 4.2 THz to 9.4 THz, and the largest MD and Q factor reaches 95% and 15.8, respectively. In addition, operation frequency range and MD can also be tuned by optimizing the structure parameters. This investigation promises the development of high-performance widely tunable THz modulator in chip integrated photonic circuits.
基金supported by the Science and Technology Planning Project of Hunan Province(Nos.2018JJ1033 and 2017RS3039).
文摘Electro-optic(EO) modulator plays a very critical role in the optical communication systems. Here, we report a stimulated thin-film lithium niobate(LN) modulator with a half-wave voltage-length product of 1.8 V·cm, which can successfully achieve modulation and demodulation of a 1 GHz sinusoidal signal with an amplitude of 5 V in experiment. The optical loss caused by metal electrodes is reduced by optimizing the waveguide structure and depositing silica onto the waveguide, and group-velocity matching and characteristic impedance matching are achieved by optimizing the buffer silica layer and the electrode structure for larger bandwidth, which simultaneously improves the modulation efficiency and bandwidth performance. Our work demonstrated here paves a foundation for integrated photonics.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61107019,61077041,61177027 and 60807029the Program for Special Funds of Basic Science&Technology of Jilin University under Grant Nos 201103071,201100253 and 200905005+1 种基金Science Foundation for Young Scientists of Jilin Province(No 20100174)Science and Technology Development Plan of Jilin Province(No 20110315).
文摘A quasi-rectangular waveguide polymer MacH^(-)Zehnder (M-Z) electro-optic (EO) modulator based on an organic/inorganic hybrid material with thermal bias control is fabricated and demonstrated.Linear bias for the modulator is obtained through thermo-optic effect.The optical output is adjusted by changing phase difference between the two arms of the M-Z interferometer.A power consumption of 16.1 m W for π phase change is observed owing to the application of silica cladding.This approach is proved to be effective to suppress direct current drift in polymer EO modulators.
文摘Fabrication and characterization of electro-optic modulators based on the novel organic electro-optic materials composed of self-assembled superlattices (SAS) were presented, both wet-dipping self-assembly and vapor phase deposition approaches were discussed. Prototype waveguide electro-optic modulators were fabricated using SAS films integrated with low-loss polymeric materials functioning as partial guiding and cladding layers.Promising electro-optic thin film materials including DTPT and PEPCOOH grown from the vapor phase were used for fabrication and test of electro-optic prototype modulators. Finally,the EO coefficient of tens of pm/V was obtained,which can sufficiently support high-speed and small size EO modulators.
基金supported by the National Natural Science Foundation of China(No.17JCYBJC16600/201386)。
文摘In this paper, an actively Q-switched wavelength injection locking random fiber laser(RFL) based on random phase-shifted fiber Bragg grating(RPS-FBG) is proposed, and the performance of the laser is verified by experiments. Within the reflection bandwidth range of RPS-FBG, spanning from 1 549.2 nm to 1 549.9 nm, different laser modes with stable central wavelength and peak power can be selectively chosen by varying the injected light wavelength. The power fluctuation within 1 h is less than 0.1 d Bm, and the central wavelength drift is less than 0.02 nm. When the pump power increases from 90 mW to 300 mW, the pulse width decreases from 3.2 μs to 1.5 μs, and the pulse repetition frequency is 20 kHz. The RFL can reach a stable locking state at the lowest pump power of 100 mW and the lowest injection power of 3 d Bm. When the wavelength is locked, the output pulse is a single pulse. On the contrary, the unlocked output pulse is multi-pulse. The laser has the characteristics of high wavelength tunability in the reflection range of RPS-FBG and it can be an ideal light source in the fields of laser imaging and pulse coding.
基金National Basic Research Program of China("973"Project , 2007CB613405 and 2006CB302803)"863"National High Technology Programme of China(2006AA03Z424)
文摘Silicon-based high-speed electro-optical modulator is the key component of silicon photonics for future communiction and interconnection systems. In this paper, introduced are the optical mudulation mechanisms in silicon, reviewed are some recent progresses in high-speed silicon modulators, and analyzed are advantages and shortages of the silicon modulators of different types.
基金supported by Ministry of Education of China Scientific Research Innovation Capability Support Project for Young Faculty under Grant No.ZYGXQNJSKYCXNLZCXM-M17the Basic Science Center Project of National Natural Science Foundation of China(NSFC)under Grant No.52388201,NSFC grants No.U24A2009 and 12474087+2 种基金Beijing Municipal Natural Science Foundation under Grant No.JQ24011 and Z240008by China Postdoctoral Science Foundation under Grant No.2023M741873.supported by Synergetic Extreme Condition User Facility(SECUF,https://cstr.cn/31123.02.SECUF).
文摘Integrated photonics has emerged as a promising alternative for data communication and computing,ferroelectric BaTiO_(3)^(-)(BTO)stands out for its exceptional electro-optic response among candidate materials.However,direct epitaxial growth of BTO entails a fundamental trade-off:substrates with low refractive index are required for strong optical confinement,yet those with large lattice mismatch degrade film crystalline quality and electro-optic performance.We report a buffer-free,strain-engineered approach to integrate high-performance BTO thin films directly on LaAlO3-Sr2TaAlO6(LSAT)oxide-insulator substrates.By exploiting a self-buffer layer formed during the initial growth stage,we achieve periodic in-plane strain modulation that stabilizes a polymorphic phase boundary with orthorhombic polar nanoregions,yielding a Pockels coefficient exceeding 358 pm V^(-1)and a Curie temperature raised to 200℃.Leveraging this material platform,we demonstrate the first realization of a Mach-Zehnder modulator using epitaxial BTO on LSAT.The device exhibits a half-wave voltage-length product of 0.7 V cm at 1550 nm,which closely matches finite-element simulations,and supports a 6-dB electro-optic bandwidth of 28 GHz.Our results validate BTO on LSAT as a viable photonic platform for scalable,low-voltage and high-speed modulators.
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.
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.
基金This work was supported by the National Natural Science Foundation of China(Nos.61690194 and 61911530162)。
文摘High-performance thin film lithium niobate(LN) electro-optic modulators with low cost are in demand. Based on photolithography and wet etching, we experimentally demonstrate a thin film LN Mach–Zehnder modulator with a 3 d B bandwidth exceeding 110 GHz, which shows the potential of boosting the throughput and reducing cost. The fabricated modulator also exhibits a comparable low half-wave voltage-length product of ~2.37 V · cm, a high extinction ratio of >23 d B, and the propagation loss of optical waveguides of ~0.2 d B/cm. Besides, six-level pulse amplitude modulation up to 250 Gb/s is successfully achieved.
文摘In this paper, we theoretically deduce the expressions of half-wave voltage and 3-dB modulation bandwidth in which conductor loss is taken into account. The results suggest that it will affect the theoretical values of half-wave voltage and bandwidth as well as the optimized electrode's dimension whether considering the conductor loss or not. As an example, we present a Mach-Zehnder (MZ) type polymer waveguide amplitude modulator. The half-wave voltage increases by 1 V and the 3-dB bandwidth decreases by 30% when the conductor loss is taken into account. Besides, the effects of impedance mismatching and velocity mismatching between microwave and light wave on the half-wave voltage, and 3-dB bandwidth are discussed.
文摘In this paper, a polymer electro-optic mod- ulator has been designed and optimized using the full vectorial finite element method. For this purpose, the effects of magnesium oxide （MgO） and down cladding thicknesses, distance between two ground electrodes, hot electrode and modulator widths modulator on the key modulator parameters, such as microwave effective index r/m, the characteristic impedance Zc and the microwave losses a are presented. After selecting optimal dimensions of polymer electro-optic modulator, frequency dependent aforementioned parameters and the half-wave voltage- length product （VπL） parameter of polymer electro-optic modulator are extracted and as a consequence, an optimized design is reported. Finally, the optical and electrical modulation responses of polymer electro-optic modulator are calculated. The optimized polymer electro- optic modulator exhibits 3-dB electrical bandwidth of 260 GHz and VπL about 2.8 V- cm in this frequency.
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The project is supported by Basic Research Foundation of Tsinghua University, No: JZ2000005.
文摘Using finite element method, lots of calculating focusing on polymer electro-optic modulators with ultra-broadband were done, a few structures were analyzed. Coplanar waveguide electrode system was advanced, a few real examples was given.
基金the National Key Research and Development Program of China(Grant No.2019YFB2203001)the National Natural Science Foundation of China(Grant Nos.61675087,61875069,and 61605057)the Science and Technology Development Plan of Jilin Province,China(Grant No.JJKH20190118KJ).
文摘Electro-optic modulator is a key component for on-chip optical signal processing.An electro-optic phase modulator based on multilayer graphene embedded in silicon nitride waveguide is demonstrated to fulfill low-power operation.Finite element method is adopted to investigate the interaction enhancement between the graphene flake and the optical mode.The impact of multilayer graphene on the performance of phase modulator is studied comprehensively.Simulation results show that the modulation efficiency improves with the increment of graphene layer number,as well as the modulation length.The 3-dB bandwidth of around 48 GHz is independent of graphene layer number and length.Compared to modulator with two-or four-layer graphene,the six-layer graphene/silicon nitride waveguide modulator can realizeπphase shift at a low-power consumption of 14 fJ/bit when the modulation length is 240μm.
基金supported by the National Key Research and Development Program of China(No.2021YFB2800104)the National Natural Science Foundation of China(Nos.62175079 and 62205119).
文摘Broadband,low-drive voltage electro-optic modulators are crucial optoelectronic components in the new-generation microwave photonic links and broadband optical interconnect network applications.In this paper,we fabricate a low-loss thinfilm lithium niobate complementary dual-output electro-optic modulator chip with a 3 dB electro-optic bandwidth of 59 GHz and a half-wave voltage(Vπ)of 2.5 V.The insert-loss of the packaged modulator is 4.2 dB after coupling with polarizationmaintaining fiber.The complementary dual-output modulator also shows a common-mode rejection ratio of 18 dB and a signal enhancement of 6.2 dB when adapted in microwave photonic links,comparable to commercial bulk lithium niobate devices.
基金supported by the National Natural Science Foundation of China(no.62304149 and no.52473318)the Zhejiang Province Natural Science Foundation of China(no.LY24E030008)+1 种基金the Key Research Program of Chinese Academy of Sciences(E4226101)supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(2021R1A2C3004202)。
文摘Controlling film morphology remains an inherent challenge limiting the performance of all-smallmolecule organic solar cells(ASM-OSCs),primarily due to excessive donor-acceptor compatibility restricting further improvements.Here,we introduce a novel strategy employing rhodanine-based film-forming kinetic modulators-specifically tailored for the high-performance donor BTR-Clincluding 3-methylrhodanine(C1),3-ethylrhodanine(C2),3-buty lr hod a nine(C4),and 3-hexylrhodanine(C6).We demonstrate that the C2 modulator uniquely optimizes morphology by extending film-formation time and fine-tuning donor-acceptor miscibility,leading to enhanced molecular ordering,uniform vertical distributio n,and optimal phase sepa ration.This synergistic morphological control significantly boosts BTR-Cl crystallinity and facilitates efficient three-dimensional charge transport networks.Consequently,C2-treated BTR-Cl:N3 ASM-OSCs achieve an outstanding power conversion efficiency(PCE)of 17.12%,ranking among the highest reported for this system.Crucially,this work introduces a novel"donor-modulator structural matching"strategy,providing a powerful new avenue for controlling film-forming kinetics to realize high-performance ASM-OSCs.
