We propose a frequency-tunable router of single photons with high routing efficiency, which is constructed by two waveguides mediately linked by a single-mode whispering gallery resonator with a driven three-level emi...We propose a frequency-tunable router of single photons with high routing efficiency, which is constructed by two waveguides mediately linked by a single-mode whispering gallery resonator with a driven three-level emitter. Quantum routing probability in the output port is obtained via the real-space Hamiltonian. By adjusting the resonator–emitter coupling and the drive, the desired continuous central frequencies for the resonance peaks of routing photons can be manipulated nearly linearly, with the assistance of Rabi splitting effect and optical Stark shift. The proposed routing system may provide potential applications in designing other frequency-modulation quantum optical devices, such as multiplexers,filters, and so on.展开更多
We have suggested a novel multiport quantum router of single photons with reflection feedback, which is formed by three waveguides coupled with four single-mode microresonators. The single-photon routing probabilities...We have suggested a novel multiport quantum router of single photons with reflection feedback, which is formed by three waveguides coupled with four single-mode microresonators. The single-photon routing probabilities of four channels in the coupled system are studied theoretically by applying the real-space approach. Numerical results indicate that unidirectional routing in these output channels can be effectively implemented, and the router is tunable to route desired frequencies into the output ports, by varying the inter-resonator detunings via spinning resonator technology. Therefore, the proposed multichannel system can provide potential applications in optical quantum communication.展开更多
The design of thermoelastic damping(TED)affected by the phase-lagging non-Fourier heat conduction effects becomes significant but challenging for enlarging the quality factor of widely-used microresonators operating i...The design of thermoelastic damping(TED)affected by the phase-lagging non-Fourier heat conduction effects becomes significant but challenging for enlarging the quality factor of widely-used microresonators operating in extreme situations,including ultra-high excitation frequency and ultra-low working temperature.However,there does not exist a rational method for designing the TED in the framework of non-Fourier heat conduction law.This work,therefore,proposes a design framework to achieve low thermoelastic dissipation of microresonators governed by the phase-lagging heat conduction law.The equation of motion and the heat conduction equation for phase-lagging TED microresonators are derived first,and then the non-Fourier TED design problem is proposed.A topology optimization-based rational design method is used to resolve the design problem.What is more,a two-dimensional(2D)plain-strain-based finite element method(FEM)is developed as a solver for the topology optimization process.Based on the suggested rational design technique,numerical instances with various phase lags are investigated.The results show that the proposed design method can remarkably reduce the dissipation of microresonators by tailoring their substructures.展开更多
In superconducting circuit,microwave resonators and capacitors are crucial components,and their quality has a strong impact on circuit performance.Here we develop a novel wet etching process to define these two compon...In superconducting circuit,microwave resonators and capacitors are crucial components,and their quality has a strong impact on circuit performance.Here we develop a novel wet etching process to define these two components using common photoresist developer as etchant.This method reduces subsequent steps and can be completed immediately after development.By measuring the internal quality factor of resonators,we show that it is possible to achieve similar or better performance when compared with samples made by standard etching processes.This easy-to-implement method may boost the yield hence providing an alternative fabrication process for microwave resonators and capacitors.展开更多
To improve the performance and reliability of microelectromechanical system's devices, it is necessary to understand the effect of friction which exists in the majority of microelectromechanical systems (MEMS) with...To improve the performance and reliability of microelectromechanical system's devices, it is necessary to understand the effect of friction which exists in the majority of microelectromechanical systems (MEMS) with a large ratio of surface area to their volume. The model of electrostatic tangential force of the shuttle in laterally driven comb microresonator is established based on the rule of energy conservation. The effects of microscale, surface roughness, applied voltage, and micro asperities or dents or holes formed in fabrication are investigated, and the electrostatic resistance between two charged moving plates is analyzed. The analytic results are coincident well with those of ANSYS simulation. It is found that the electrostatic resistance becomes high as the increase of the ratio of the shuttle width to the gap between moving plates and the relative surface roughness or the increment of the applied voltage.展开更多
The stabilization and manipulation of laser frequency by means of an external cavity are nearly ubiquitously used in fundamental research and laser applications. While most of the laser light transmits through the cav...The stabilization and manipulation of laser frequency by means of an external cavity are nearly ubiquitously used in fundamental research and laser applications. While most of the laser light transmits through the cavity, in the presence of some back-scattered light from the cavity to the laser, the self-injection locking effect can take place, which locks the laser emission frequency to the cavity mode of similar frequency. The self-injection locking leads to dramatic reduction of laser linewidth and noise. Using this approach, a common semiconductor laser locked to an ultrahigh-Q microresonator can obtain sub-Hertz linewidth, on par with state-of-the-art fiber lasers. Therefore it paves the way to manufacture high-performance semiconductor lasers with reduced footprint and cost. Moreover, with high laser power, the optical nonlinearity of the microresonator drastically changes the laser dynamics, offering routes for simultaneous pulse and frequency comb generation in the same microresonator. Particularly, integrated photonics technology, enabling components fabricated via semiconductor CMOS process, has brought increasing and extending interest to laser manufacturing using this method. In this article, we present a comprehensive tutorial on analytical and numerical methods of laser self-injection locking, as well a review of most recent theoretical and experimental achievements.展开更多
Chiral quantum optics is a new research area in light-matter interaction that depends on the direction of light propagation and offers a new path for the quantum regulation of light-matter interactions.In this paper,w...Chiral quantum optics is a new research area in light-matter interaction that depends on the direction of light propagation and offers a new path for the quantum regulation of light-matter interactions.In this paper,we study a spinning Kerr-type microresonator coupled withΛ-type atom ensembles,which are driven in opposite directions to generate asymmetric photon statistics.We find that a photon blockade can only be generated by driving the spinning resonator on right side without driving the spinning microresonator from the left side,resulting in chirality.The coupling strength between system modes can be precisely controlled by adjusting the detuning amount of the atomic pump field.Because of the splitting of the resonant frequency generated by the Fizeau drag,the destructive quantum interference generated in right side drive prevents the nonresonant transition path of state|1,0⟩to state|2,0⟩.This direction-dependent chiral quantum optics is expected to be applied to chiral optical devices,single-photon sources and nonreciprocal quantum communications.展开更多
Second-order(χ^((2))) optical nonlinearity is one of the most common mechanisms for modulating and generating coherent light in photonic devices.Due to strong photon confnement and long photon lifetime,integrated mic...Second-order(χ^((2))) optical nonlinearity is one of the most common mechanisms for modulating and generating coherent light in photonic devices.Due to strong photon confnement and long photon lifetime,integrated microresonators have emerged as an ideal platform for investigation of nonlinear optical efects.However,existing silicon-based materials lack a χ^((2)) response due to their centrosymmetric structures.A variety of novel material platforms possessing χ^((2)) nonlinearity have been developed over the past two decades.This review comprehensively summarizes the progress of second-order nonlinear optical efects in integrated microresonators.First,the basic principles of χ^((2)) nonlinear efects are introduced.Afterward,we highlight the commonly used χ^((2)) nonlinear optical materials,including their material properties and respective functional devices.We also discuss the prospects and challenges of utilizing χ^((2)) nonlinearity in the feld of integrated microcavity photonics.展开更多
We investigate the mechanisms to realize the Raman laser switching in a silica rod microresonator with mode-interactionassisted excitation.The laser switching can be triggered between two whispering gallery modes[WGMs...We investigate the mechanisms to realize the Raman laser switching in a silica rod microresonator with mode-interactionassisted excitation.The laser switching can be triggered between two whispering gallery modes[WGMs]with either the same or distinct mode families,depending on the pumping conditions.The experimental observations are in excellent agreement with a theoretical analysis based on coupled-mode equations with intermodal interaction terms involved.Additionally,we also demonstrate switching of a single-mode Raman laser and a wideband spectral tuning range up to~32.67 nm by selective excitation of distinct mode sequences.The results contribute to the understanding of Raman lasing formation dynamics via interaction with transverse mode sequences and may extend the microcavity-based Raman microlasers to potential areas in switchable light sources,optical memories,and high sensitivity sensors.展开更多
Single-mode lasing in whispering-gallery mode(WGM)microresonators is challenging to achieve.In bottle microresonators,the highly non-degenerated WGMs are spatially well-separated along the long-axis direction and prov...Single-mode lasing in whispering-gallery mode(WGM)microresonators is challenging to achieve.In bottle microresonators,the highly non-degenerated WGMs are spatially well-separated along the long-axis direction and provide mode-selection capability.In this work,by engineering the pump intensity to modify the spatial gain profiles of bottle microresonators,we demonstrate a simple and general approach to realizing single-mode WGM lasing in polymer bottle microresonators.The pump intensity is engineered into an interference distribution on the bottle microresonator surface.By tuning the spacing between axial positions of the interference pump patterns,the mode intensity profiles of single-bottle WGMs can be spatially overlapped with the interference stripes,intrinsically enabling single-mode lasing and selection.Attractive advantages of the system,including high sidemode suppression factors 420 dB,large spectral tunability 48 nm,low-lasing threshold and reversible control,are presented.Our demonstrated approach may have a variety of promising applications,ranging from tunable single-mode lasing and sensing to nonlinear optics.展开更多
The microresonator-based soliton microcomb has shown a promising future in many applications.In this work,we report the fabrication of high quality[Q]Si_(3)N_(4)microring resonators for soliton microcomb generation.By...The microresonator-based soliton microcomb has shown a promising future in many applications.In this work,we report the fabrication of high quality[Q]Si_(3)N_(4)microring resonators for soliton microcomb generation.By developing the fabri-cation process with crack isolation trenches and annealing,we can deposit thick stoichiometric Si3N4 film of 800 nm without cracks in the central area.The highest intrinsic Q of the Si_(3)N_(4)microring obtained in our experiments is about 6×10^(6),corresponding to a propagation loss as low as 0.058 dBm/cm.With such a high Q film,we fabricate microrings with the anomalous dispersion and demonstrate the generation of soliton microcombs with 100 mW on-chip pump power,with an optical parametric oscillation threshold of only 13.4 mW.Our Si_(3)N_(4)integrated chip provides an ideal platform for researches and applications of nonlinear photonics and integrated photonics.展开更多
On-chip bright quantum sources with multiplexing ability are extremely high in demand for integrated quantum networks with unprecedented scalability and complexity.Here,we demonstrate a bright and broadband biphoton q...On-chip bright quantum sources with multiplexing ability are extremely high in demand for integrated quantum networks with unprecedented scalability and complexity.Here,we demonstrate a bright and broadband biphoton quantum source with spectral multiplexing generated in a lithium niobate microresonator system.Without introducing the conventional domain poling,the on-chip microdisk produces photon pairs covering a broad bandwidth promised by natural phase matching in spontaneous parametric down conversion.Experimentally,the multiplexed photon pairs are characterized by 30 nm bandwidth limited by the filtering system,providing over 40 multiplexing channels with a 0.8 nm channel spacing.Meanwhile,the generation rate reaches 5.13 MHz/μW with a coincidence-to-accidental ratio up to 804,and the quantum source manifests a high purity with a heralded single photon correlation g^((2))_(H)(0)=0.0098±0.0021.Furthermore,the energy-time entanglement is demonstrated with an excellent interference visibility of 96.5%±2%.Such a quantum source at the telecommunication band paves the way for high-dimensional entanglement and future integrated quantum information systems.展开更多
We report on the transmission spectra of a sausage-like microresonator(SLM)in aqueous environment,where a fiber taper is used as a light coupler.The transmission spectra show an interesting dependence on the coupling ...We report on the transmission spectra of a sausage-like microresonator(SLM)in aqueous environment,where a fiber taper is used as a light coupler.The transmission spectra show an interesting dependence on the coupling position between the SLM and the fiber taper.When the SLM is moved along the fiber taper,the line shape can evolve periodically among symmetric dips,asymmetric Fano-like resonance line shapes,and symmetric peaks.A coupled-mode theory with feedback is developed to explain the observation.The observation of Fano-like resonance in aqueous environment holds great potential in biochemical sensing.展开更多
Dual combs are an emerging tool to obtain unprecedented resolution, high sensitivity, ultrahigh accuracy, broabandwidth, and ultrafast data updating rate in the fields of molecular spectroscopy, optical metrology, as ...Dual combs are an emerging tool to obtain unprecedented resolution, high sensitivity, ultrahigh accuracy, broabandwidth, and ultrafast data updating rate in the fields of molecular spectroscopy, optical metrology, as well optical frequency synthesis. The recent progress in chip-based microcombs has promoted the on-chip dual-commeasuring systems to a new phase attributed to the large frequency spacing and broad spectrum. In this paper, wdemonstrate proof-of-concept dual-comb generation with orthogonal polarization in a single microresonatthrough pumping both the transverse-electric(TE) and transverse-magnetic(TM) modes simultaneously. Ttwo orthogonal polarized pumps are self-oscillating in a fiber ring cavity. The generated dual comb exhibits ecellent stability due to the intrinsic feedback mechanism of the self-locked scheme. The repetition rate the two orthogonal combs is slightly different because of the mode spacing difference between the TE anTM modes. Such orthogonal polarized dual-combs could be a new comb source for out-of-lab applicatioin the fields of integrated spectroscopy, ranging measurement, optical frequency synthesis, and microwacomb generation.展开更多
Due to the lack of mode selection capability, single whispering-gallery-mode(WGM) lasing is a challenge to achieve. In bottle microresonators, the highly nondegenerated WGMs are spatially well-separated along the long...Due to the lack of mode selection capability, single whispering-gallery-mode(WGM) lasing is a challenge to achieve. In bottle microresonators, the highly nondegenerated WGMs are spatially well-separated along the long-axis direction and provide mode selection according to their axial mode numbers. In this work, we use a loss-engineering approach to suppress the higher-order WGMs and demonstrate single-mode lasing emission in small polymer bottle microresonators. The fiber tapers are not only used to couple pump light into the bottle microresonators to excite the WGMs but also to bring optical losses that are induced from the diameter mismatch between fiber tapers and microresonators. By adjusting the coupling positions, the diameters of fiber tapers, and the coupling angles, single fundamental-mode lasing is efficiently generated with side-mode suppression factors over 15 dB. Our loss-engineering approach is convenient just by moving the fiber taper and may findpromising applications in miniature tunable single-mode lasers and sensors.展开更多
Ultra-high quality(Q) whispering gallery mode(WGM) microtoroid optical resonators have demonstrated highly sensitive biomolecular detection down to the single molecule limit;however, the lack of a robust coupling meth...Ultra-high quality(Q) whispering gallery mode(WGM) microtoroid optical resonators have demonstrated highly sensitive biomolecular detection down to the single molecule limit;however, the lack of a robust coupling method has prevented their widespread adoption outside the laboratory. We demonstrate through simulation that a phased array of nanorods can enable free-space coupling of light both into and out of a microtoroid while maintaining a high Q. To simulate large nanostructured WGM resonators, we developed a new approach known as FloWBEM,which is an efficient and compact 3D wedge model with custom boundary conditions that accurately simulate the resonant Fano interference between the traveling WGM waves and a nanorod array. Depending on the excitation conditions, we find loaded Q factors of the driven system as high as 2.1 × 10~7 and signal-to-background ratios as high as 3.86%, greater than the noise levels of many commercial detectors. These results can drive future experimental implementation.展开更多
In this paper, a multidimensional tuning method of the silica microcapillary resonator(MCR) is proposed and demonstrated whereby the extinction ratio(ER) as well as the resonant wavelength can be individually controll...In this paper, a multidimensional tuning method of the silica microcapillary resonator(MCR) is proposed and demonstrated whereby the extinction ratio(ER) as well as the resonant wavelength can be individually controlled.An ER tuning range of up to 17 d B and a maximum tuning sensitivity of 0.3 d B/μm are realized due to the tapered profile of the silica optical microfiber(MF) when the MF is adjusted along its axial direction. Compared to direct tuning of the coupling gap, this method could lower the requirement for the resolution of displacement stage to micrometers. When the MF is adjusted along the axial direction of the silica microcapillary, a resonance shift of 3.06 nm and maximum tuning sensitivity of 0.01 nm/μm are achieved. This method avoids the use of an applied external field to control the silica microresonators. Moreover, when air is replaced by ethanol and water in the core of the silica microcapillary, a maximum resonance shift of 5.22 nm is also achieved to further enlarge the resonance tuning range. Finally, a microbubble resonator with a higher Q factor is also fabricated to achieve an ER tuning range of 8.5 d B. Our method fully takes advantage of the unique structure of the MCR to separately and easily tune its key parameters, and may broaden its applications in optical signal processing and sensing.展开更多
Stable dual-mode semiconductor lasers can be applied for the photonic generation of microwave and terahertz waves. In this paper, the mode characteristics of a variable curvature microresonator are investigated by a t...Stable dual-mode semiconductor lasers can be applied for the photonic generation of microwave and terahertz waves. In this paper, the mode characteristics of a variable curvature microresonator are investigated by a twodimensional finite element method for realizing stable dual-mode lasing. The microresonator features a smooth boundary and the same symmetry as a square resonator. A small variable-curvature microresonator with a radius of 4 μm can support the fundamental four-bounce mode and the circular-like mode simultaneously, with quality factors up to the order of 10~4 and 10~5, respectively. The dual modes in the phase space of the Poincarésurface of sections distribute far from each other and can maintain enough stability for dual-mode lasing.Furthermore, the refractive index and waveguide can modulate the dual-mode wavelength difference and quality factors efficiently thanks to the spatially separated fields of these two modes.展开更多
Simultaneous Kerr comb formation and second-harmonic generation with on-chip microresonators can greatly facilitate comb self-referencing for optical clocks and frequency metrology.Moreover,the presence of both second...Simultaneous Kerr comb formation and second-harmonic generation with on-chip microresonators can greatly facilitate comb self-referencing for optical clocks and frequency metrology.Moreover,the presence of both second-and third-order nonlinearities results in complex cavity dynamics that is of high scientific interest but is still far from being well-understood.Here,we demonstrate that the interaction between the fundamental and the second-harmonic waves can provide an entirely new way of phase matching for four-wave mixing in optical microresonators,enabling the generation of optical frequency combs in the normal dispersion regime under conditions where comb creation is ordinarily prohibited.We derive new coupled time-domain mean-field equations and obtain simulation results showing good qualitative agreement with our experimental observations.Our findings provide a novel way of overcoming the dispersion limit for simultaneous Kerr comb formation and second-harmonic generation,which might prove to be especially important in the near-visible to visible range where several atomic transitions commonly used for the stabilization of optical clocks are located and where the large normal material dispersion is likely to dominate.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12365003, 12364024, and 11864014)the Natural Science Foundation of Jiangxi Province, China (Grant Nos. 20212BAB201014 and 20224BAB201023)。
文摘We propose a frequency-tunable router of single photons with high routing efficiency, which is constructed by two waveguides mediately linked by a single-mode whispering gallery resonator with a driven three-level emitter. Quantum routing probability in the output port is obtained via the real-space Hamiltonian. By adjusting the resonator–emitter coupling and the drive, the desired continuous central frequencies for the resonance peaks of routing photons can be manipulated nearly linearly, with the assistance of Rabi splitting effect and optical Stark shift. The proposed routing system may provide potential applications in designing other frequency-modulation quantum optical devices, such as multiplexers,filters, and so on.
文摘We have suggested a novel multiport quantum router of single photons with reflection feedback, which is formed by three waveguides coupled with four single-mode microresonators. The single-photon routing probabilities of four channels in the coupled system are studied theoretically by applying the real-space approach. Numerical results indicate that unidirectional routing in these output channels can be effectively implemented, and the router is tunable to route desired frequencies into the output ports, by varying the inter-resonator detunings via spinning resonator technology. Therefore, the proposed multichannel system can provide potential applications in optical quantum communication.
基金This work is partially supported by National Natural Science Foundation of China (11774102), the Scientific Research Funds and Promotion Program for Young and Middle-aged Teacher in Science & Technology Research of Huaqiao University (ZQN-YXS04, 17BS412), Open Fund of IPOC (BUPT), National Research Foundation Singapore (NRF) (NRF-CRP13-2014-05), European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement (No. 798916) and Singapore Ministry of Education Academic Research Fund Tier 1 (RG89/16).
基金supported by the National Natural Science Foundation of China(No.52175095)the Young Top-Notch Talent Cultivation Program of Hubei Province of China。
文摘The design of thermoelastic damping(TED)affected by the phase-lagging non-Fourier heat conduction effects becomes significant but challenging for enlarging the quality factor of widely-used microresonators operating in extreme situations,including ultra-high excitation frequency and ultra-low working temperature.However,there does not exist a rational method for designing the TED in the framework of non-Fourier heat conduction law.This work,therefore,proposes a design framework to achieve low thermoelastic dissipation of microresonators governed by the phase-lagging heat conduction law.The equation of motion and the heat conduction equation for phase-lagging TED microresonators are derived first,and then the non-Fourier TED design problem is proposed.A topology optimization-based rational design method is used to resolve the design problem.What is more,a two-dimensional(2D)plain-strain-based finite element method(FEM)is developed as a solver for the topology optimization process.Based on the suggested rational design technique,numerical instances with various phase lags are investigated.The results show that the proposed design method can remarkably reduce the dissipation of microresonators by tailoring their substructures.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFA0301802)the National Natural Science Foundation of China(Grant Nos.61521001 and 11890704)the Key R&D Program of Guangdong Province,China(Grant No.2018B030326001).
文摘In superconducting circuit,microwave resonators and capacitors are crucial components,and their quality has a strong impact on circuit performance.Here we develop a novel wet etching process to define these two components using common photoresist developer as etchant.This method reduces subsequent steps and can be completed immediately after development.By measuring the internal quality factor of resonators,we show that it is possible to achieve similar or better performance when compared with samples made by standard etching processes.This easy-to-implement method may boost the yield hence providing an alternative fabrication process for microwave resonators and capacitors.
基金National Natural Science Foundation of China(No.50135040)Science Foundation of Shanghai Municipality Education Commission through the Key Discipline Program(No.970104).
文摘To improve the performance and reliability of microelectromechanical system's devices, it is necessary to understand the effect of friction which exists in the majority of microelectromechanical systems (MEMS) with a large ratio of surface area to their volume. The model of electrostatic tangential force of the shuttle in laterally driven comb microresonator is established based on the rule of energy conservation. The effects of microscale, surface roughness, applied voltage, and micro asperities or dents or holes formed in fabrication are investigated, and the electrostatic resistance between two charged moving plates is analyzed. The analytic results are coincident well with those of ANSYS simulation. It is found that the electrostatic resistance becomes high as the increase of the ratio of the shuttle width to the gap between moving plates and the relative surface roughness or the increment of the applied voltage.
基金The results presented in Sections 2.5 and 3.2 were obtained with the support of the Russian Science Foundation(project 22-22-00872)The results presented in Sections 2.3,3.4 and 4 were obtained with the support of the Russian Science Foundation(Project 20-12-00344)+5 种基金Y.-H.L.acknowledges support from the China Postdoctoral Science Foundation(Grant No.2022M721482)W.L.acknowledges support from the National Natural Science Foundation of China(Grant No.62075233)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-69)J.L.acknowledges support from the National Natural Science Foundation of China(Grant No.12261131503)Shenzhen−Hong Kong Cooperation Zone for Technology and Innovation(HZQB-KCZYB2020050)from the Guangdong Provincial Key Laboratory(2019B121203002).
文摘The stabilization and manipulation of laser frequency by means of an external cavity are nearly ubiquitously used in fundamental research and laser applications. While most of the laser light transmits through the cavity, in the presence of some back-scattered light from the cavity to the laser, the self-injection locking effect can take place, which locks the laser emission frequency to the cavity mode of similar frequency. The self-injection locking leads to dramatic reduction of laser linewidth and noise. Using this approach, a common semiconductor laser locked to an ultrahigh-Q microresonator can obtain sub-Hertz linewidth, on par with state-of-the-art fiber lasers. Therefore it paves the way to manufacture high-performance semiconductor lasers with reduced footprint and cost. Moreover, with high laser power, the optical nonlinearity of the microresonator drastically changes the laser dynamics, offering routes for simultaneous pulse and frequency comb generation in the same microresonator. Particularly, integrated photonics technology, enabling components fabricated via semiconductor CMOS process, has brought increasing and extending interest to laser manufacturing using this method. In this article, we present a comprehensive tutorial on analytical and numerical methods of laser self-injection locking, as well a review of most recent theoretical and experimental achievements.
基金the support from the National Natural Science Foundation of China under Grant Nos.62071064 and 62131002the Fundamental Research Funds for the Central Universities of China under Grant No.2019XD-A02the Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)(No.IPOC2022ZT10),China.
文摘Chiral quantum optics is a new research area in light-matter interaction that depends on the direction of light propagation and offers a new path for the quantum regulation of light-matter interactions.In this paper,we study a spinning Kerr-type microresonator coupled withΛ-type atom ensembles,which are driven in opposite directions to generate asymmetric photon statistics.We find that a photon blockade can only be generated by driving the spinning resonator on right side without driving the spinning microresonator from the left side,resulting in chirality.The coupling strength between system modes can be precisely controlled by adjusting the detuning amount of the atomic pump field.Because of the splitting of the resonant frequency generated by the Fizeau drag,the destructive quantum interference generated in right side drive prevents the nonresonant transition path of state|1,0⟩to state|2,0⟩.This direction-dependent chiral quantum optics is expected to be applied to chiral optical devices,single-photon sources and nonreciprocal quantum communications.
基金the National Key Research and Development Program of China(No.2021YFB2800604)the National Natural Science Foundation of China(Grant Nos.91850115 and 11774110)the State Key Laboratory of Applied Optics(No.SKLAO2021001A10).
文摘Second-order(χ^((2))) optical nonlinearity is one of the most common mechanisms for modulating and generating coherent light in photonic devices.Due to strong photon confnement and long photon lifetime,integrated microresonators have emerged as an ideal platform for investigation of nonlinear optical efects.However,existing silicon-based materials lack a χ^((2)) response due to their centrosymmetric structures.A variety of novel material platforms possessing χ^((2)) nonlinearity have been developed over the past two decades.This review comprehensively summarizes the progress of second-order nonlinear optical efects in integrated microresonators.First,the basic principles of χ^((2)) nonlinear efects are introduced.Afterward,we highlight the commonly used χ^((2)) nonlinear optical materials,including their material properties and respective functional devices.We also discuss the prospects and challenges of utilizing χ^((2)) nonlinearity in the feld of integrated microcavity photonics.
基金supported by the National Natural Science Foundation of China(No.62005071)the Natural Science Foundation of Anhui Province(No.2008085QF312)+1 种基金the Fundamental Research Funds for the Central Universities(No.JZ2021HGTB0079)the National Key Research and Development Program of China(No.2019YFE010747)。
文摘We investigate the mechanisms to realize the Raman laser switching in a silica rod microresonator with mode-interactionassisted excitation.The laser switching can be triggered between two whispering gallery modes[WGMs]with either the same or distinct mode families,depending on the pumping conditions.The experimental observations are in excellent agreement with a theoretical analysis based on coupled-mode equations with intermodal interaction terms involved.Additionally,we also demonstrate switching of a single-mode Raman laser and a wideband spectral tuning range up to~32.67 nm by selective excitation of distinct mode sequences.The results contribute to the understanding of Raman lasing formation dynamics via interaction with transverse mode sequences and may extend the microcavity-based Raman microlasers to potential areas in switchable light sources,optical memories,and high sensitivity sensors.
基金supported by the National Natural Science Foundation of China(11674230)973 Program(2015CB352001)National Natural Science Foundation of China(11434005).
文摘Single-mode lasing in whispering-gallery mode(WGM)microresonators is challenging to achieve.In bottle microresonators,the highly non-degenerated WGMs are spatially well-separated along the long-axis direction and provide mode-selection capability.In this work,by engineering the pump intensity to modify the spatial gain profiles of bottle microresonators,we demonstrate a simple and general approach to realizing single-mode WGM lasing in polymer bottle microresonators.The pump intensity is engineered into an interference distribution on the bottle microresonator surface.By tuning the spacing between axial positions of the interference pump patterns,the mode intensity profiles of single-bottle WGMs can be spatially overlapped with the interference stripes,intrinsically enabling single-mode lasing and selection.Attractive advantages of the system,including high sidemode suppression factors 420 dB,large spectral tunability 48 nm,low-lasing threshold and reversible control,are presented.Our demonstrated approach may have a variety of promising applications,ranging from tunable single-mode lasing and sensing to nonlinear optics.
基金This work was supported by the National Key Research and Development Program of China(No.2020YFB2205801)National Natural Science Foundation of China(Nos.11934012,11874342,and 92050109)the Fundamental Research Funds for the Central Universities.C.H.Dong was also supported by the State Key Laboratory of Advanced Optical Communication Systems and Networks,Shanghai Jiao Tong University,China.This work was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.The authors declare no conflicts of interest.
文摘The microresonator-based soliton microcomb has shown a promising future in many applications.In this work,we report the fabrication of high quality[Q]Si_(3)N_(4)microring resonators for soliton microcomb generation.By developing the fabri-cation process with crack isolation trenches and annealing,we can deposit thick stoichiometric Si3N4 film of 800 nm without cracks in the central area.The highest intrinsic Q of the Si_(3)N_(4)microring obtained in our experiments is about 6×10^(6),corresponding to a propagation loss as low as 0.058 dBm/cm.With such a high Q film,we fabricate microrings with the anomalous dispersion and demonstrate the generation of soliton microcombs with 100 mW on-chip pump power,with an optical parametric oscillation threshold of only 13.4 mW.Our Si_(3)N_(4)integrated chip provides an ideal platform for researches and applications of nonlinear photonics and integrated photonics.
基金supported by the National Key R&D Program of China(Grant Nos.2016YFA0301302,and 2016YFA0301700)National Natural Science Foundation of China(Grant Nos.11825402,61590932,11774333,62061160487,12004373,11734009,and 11874375)+4 种基金Anhui Initiative in Quantum Information Technologies(Grant No.AHY130300)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB24030601)Beijing Academy of Quantum Information Sciences(Grant No.Y18G20)Fundamental Research Funds for the Central Universitiespartially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘On-chip bright quantum sources with multiplexing ability are extremely high in demand for integrated quantum networks with unprecedented scalability and complexity.Here,we demonstrate a bright and broadband biphoton quantum source with spectral multiplexing generated in a lithium niobate microresonator system.Without introducing the conventional domain poling,the on-chip microdisk produces photon pairs covering a broad bandwidth promised by natural phase matching in spontaneous parametric down conversion.Experimentally,the multiplexed photon pairs are characterized by 30 nm bandwidth limited by the filtering system,providing over 40 multiplexing channels with a 0.8 nm channel spacing.Meanwhile,the generation rate reaches 5.13 MHz/μW with a coincidence-to-accidental ratio up to 804,and the quantum source manifests a high purity with a heralded single photon correlation g^((2))_(H)(0)=0.0098±0.0021.Furthermore,the energy-time entanglement is demonstrated with an excellent interference visibility of 96.5%±2%.Such a quantum source at the telecommunication band paves the way for high-dimensional entanglement and future integrated quantum information systems.
基金National Natural Science Foundation of China(NSFC)(11674059,61275215)Fujian Provincial College Funds for Distinguished Young Scientists(JA14070)+1 种基金Natural Science Foundation of Fujian Province(2016J01008,2016J01009)Open Project of Key Laboratory of Quantum Information Chinese Academy of Sciences(CAS)(KQI201601)
文摘We report on the transmission spectra of a sausage-like microresonator(SLM)in aqueous environment,where a fiber taper is used as a light coupler.The transmission spectra show an interesting dependence on the coupling position between the SLM and the fiber taper.When the SLM is moved along the fiber taper,the line shape can evolve periodically among symmetric dips,asymmetric Fano-like resonance line shapes,and symmetric peaks.A coupled-mode theory with feedback is developed to explain the observation.The observation of Fano-like resonance in aqueous environment holds great potential in biochemical sensing.
基金National Natural Science Foundation of China(NSFC)(61475188,61605151,61635013,61675231)Strategic Priority Research Program,Chinese Academy of Sciences(CAS)(XDB24030600)
文摘Dual combs are an emerging tool to obtain unprecedented resolution, high sensitivity, ultrahigh accuracy, broabandwidth, and ultrafast data updating rate in the fields of molecular spectroscopy, optical metrology, as well optical frequency synthesis. The recent progress in chip-based microcombs has promoted the on-chip dual-commeasuring systems to a new phase attributed to the large frequency spacing and broad spectrum. In this paper, wdemonstrate proof-of-concept dual-comb generation with orthogonal polarization in a single microresonatthrough pumping both the transverse-electric(TE) and transverse-magnetic(TM) modes simultaneously. Ttwo orthogonal polarized pumps are self-oscillating in a fiber ring cavity. The generated dual comb exhibits ecellent stability due to the intrinsic feedback mechanism of the self-locked scheme. The repetition rate the two orthogonal combs is slightly different because of the mode spacing difference between the TE anTM modes. Such orthogonal polarized dual-combs could be a new comb source for out-of-lab applicatioin the fields of integrated spectroscopy, ranging measurement, optical frequency synthesis, and microwacomb generation.
基金National Natural Science Foundation of China(NSFC)(11674230)973 Program(2015CB352001)
文摘Due to the lack of mode selection capability, single whispering-gallery-mode(WGM) lasing is a challenge to achieve. In bottle microresonators, the highly nondegenerated WGMs are spatially well-separated along the long-axis direction and provide mode selection according to their axial mode numbers. In this work, we use a loss-engineering approach to suppress the higher-order WGMs and demonstrate single-mode lasing emission in small polymer bottle microresonators. The fiber tapers are not only used to couple pump light into the bottle microresonators to excite the WGMs but also to bring optical losses that are induced from the diameter mismatch between fiber tapers and microresonators. By adjusting the coupling positions, the diameters of fiber tapers, and the coupling angles, single fundamental-mode lasing is efficiently generated with side-mode suppression factors over 15 dB. Our loss-engineering approach is convenient just by moving the fiber taper and may findpromising applications in miniature tunable single-mode lasers and sensors.
基金National Key R&D Program of China(2016YFA0301300)National Natural Science Foundation of China(NSFC)(61671090,61875021)+4 种基金Natural Science Foundation of Beijing Municipality(2192036)China Scholarship Council(CSC)(201706470049)Beijing University of Posts and Telecommunications Excellent Ph.D.Students Foundation(CX2017302)DeMund Foundation Graduate Student Endowed Scholarship in Optical and Medical Sciences Friends of Tucson Optics(FOTO)ScholarshipDefense Threat Reduction Agency(DTRA)(HDTRA1-18-1-0044)
文摘Ultra-high quality(Q) whispering gallery mode(WGM) microtoroid optical resonators have demonstrated highly sensitive biomolecular detection down to the single molecule limit;however, the lack of a robust coupling method has prevented their widespread adoption outside the laboratory. We demonstrate through simulation that a phased array of nanorods can enable free-space coupling of light both into and out of a microtoroid while maintaining a high Q. To simulate large nanostructured WGM resonators, we developed a new approach known as FloWBEM,which is an efficient and compact 3D wedge model with custom boundary conditions that accurately simulate the resonant Fano interference between the traveling WGM waves and a nanorod array. Depending on the excitation conditions, we find loaded Q factors of the driven system as high as 2.1 × 10~7 and signal-to-background ratios as high as 3.86%, greater than the noise levels of many commercial detectors. These results can drive future experimental implementation.
基金National Natural Science Foundation of China(NSFC)(61307075)Specialized Research Fund for the Doctoral Program of Higher Education of China(20120142120067)+1 种基金Fundamental Research Funds for the Central Universities(HUST:2014TS019)Director Fund of Wuhan National Laboratory for Optoelectronics
文摘In this paper, a multidimensional tuning method of the silica microcapillary resonator(MCR) is proposed and demonstrated whereby the extinction ratio(ER) as well as the resonant wavelength can be individually controlled.An ER tuning range of up to 17 d B and a maximum tuning sensitivity of 0.3 d B/μm are realized due to the tapered profile of the silica optical microfiber(MF) when the MF is adjusted along its axial direction. Compared to direct tuning of the coupling gap, this method could lower the requirement for the resolution of displacement stage to micrometers. When the MF is adjusted along the axial direction of the silica microcapillary, a resonance shift of 3.06 nm and maximum tuning sensitivity of 0.01 nm/μm are achieved. This method avoids the use of an applied external field to control the silica microresonators. Moreover, when air is replaced by ethanol and water in the core of the silica microcapillary, a maximum resonance shift of 5.22 nm is also achieved to further enlarge the resonance tuning range. Finally, a microbubble resonator with a higher Q factor is also fabricated to achieve an ER tuning range of 8.5 d B. Our method fully takes advantage of the unique structure of the MCR to separately and easily tune its key parameters, and may broaden its applications in optical signal processing and sensing.
基金National Natural Science Foundation of China(NSFC)(61235004,61377105,61527823)
文摘Stable dual-mode semiconductor lasers can be applied for the photonic generation of microwave and terahertz waves. In this paper, the mode characteristics of a variable curvature microresonator are investigated by a twodimensional finite element method for realizing stable dual-mode lasing. The microresonator features a smooth boundary and the same symmetry as a square resonator. A small variable-curvature microresonator with a radius of 4 μm can support the fundamental four-bounce mode and the circular-like mode simultaneously, with quality factors up to the order of 10~4 and 10~5, respectively. The dual modes in the phase space of the Poincarésurface of sections distribute far from each other and can maintain enough stability for dual-mode lasing.Furthermore, the refractive index and waveguide can modulate the dual-mode wavelength difference and quality factors efficiently thanks to the spatially separated fields of these two modes.
基金supported in part by the National Science Foundation under grant ECCS-1509578the Air Force Office of Scientific Research under grant FA9550-15-1-0211+3 种基金the DARPA PULSE program through grant W31P40-13-1-0018 from AMRDECfunding from the National Natural Science Foundation of China under grant 6169190011/12,61420106003the Beijing Natural Science Foundation under grant 4172029funding from the Marsden Fund and the Rutherford Discovery Fellowships of the Royal Society of New Zealand.
文摘Simultaneous Kerr comb formation and second-harmonic generation with on-chip microresonators can greatly facilitate comb self-referencing for optical clocks and frequency metrology.Moreover,the presence of both second-and third-order nonlinearities results in complex cavity dynamics that is of high scientific interest but is still far from being well-understood.Here,we demonstrate that the interaction between the fundamental and the second-harmonic waves can provide an entirely new way of phase matching for four-wave mixing in optical microresonators,enabling the generation of optical frequency combs in the normal dispersion regime under conditions where comb creation is ordinarily prohibited.We derive new coupled time-domain mean-field equations and obtain simulation results showing good qualitative agreement with our experimental observations.Our findings provide a novel way of overcoming the dispersion limit for simultaneous Kerr comb formation and second-harmonic generation,which might prove to be especially important in the near-visible to visible range where several atomic transitions commonly used for the stabilization of optical clocks are located and where the large normal material dispersion is likely to dominate.