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
Optical whispering gallery mode （WGM） microresonators have attracted great attention due to their remarkable proper- ties such as extremely high quality factor, small mode volume, tight confinement of modes, and str...Optical whispering gallery mode （WGM） microresonators have attracted great attention due to their remarkable proper- ties such as extremely high quality factor, small mode volume, tight confinement of modes, and strong evanescent field. All these properties of WGM microresonators have ensured their great potentials for applications, such as physical sen- sors, bio/chemical sensors and microlasers. In this mini-review, the key parameters and coupling conditions of WGM microresonators are firstly introduced. The geometries of WGM optical microcavities are presented based on their fabri- cation methods. This is followed by the discussion on the state-of-the-art applications of WGM microresonators in sen- sors and microlasers.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
Chip-based optical microresonators with ultra-high Q-factors are becoming increasingly important to a variety of applications. However, the losses of on-chip microresonators with the highest Q-factor reported in the p...Chip-based optical microresonators with ultra-high Q-factors are becoming increasingly important to a variety of applications. However, the losses of on-chip microresonators with the highest Q-factor reported in the past are still far from their material absorption limits. Here, we demonstrate an on-chip silica microresonator that has approached the absorption limit of the state-of-the-art material on chip, realizing, to our knowledge, record intrinsic Q-factors exceeding 3 billion at both 1560 nm and 1064 nm. This fact is corroborated by photo-thermal spectroscopy measurements. Especially, compared with the standard optical fibers, its corresponding optical losses are only 38.4 times and 7.7 times higher at the wavelengths of 1560 nm and 1064 nm, respectively.To exhibit the performance of such fabricated microresonator, we achieve a record-low optical parametric oscillation threshold(31.9 μW) for millimeter-sized microresonators and generate a single-soliton microcomb with a record-low pump power of 220.2 μW for all soliton microcombs realized thus far.展开更多
With the rapid development of the Internet of Things and big data,integrated optical switches are gaining prominence for applications in on-chip optical computing,optical memories,and optical communications.Here,we pr...With the rapid development of the Internet of Things and big data,integrated optical switches are gaining prominence for applications in on-chip optical computing,optical memories,and optical communications.Here,we propose a novel approach for on-chip optical switches by utilizing the nonlinear optical Kerr effect induced spontaneous symmetry breaking(SSB),which leads to two distinct states of counterpropagating light in ring resonators.This technique is based on our first experimental observation of on-chip symmetry breaking in a high-Q(9.4×10~6)silicon nitride resonator with a measured SSB threshold power of approximately 3.9 mW.We further explore the influence of varying pump powers and frequency detunings on the performance of SSB-induced optical switches.Our work provides insights into the development of new types of photonic data processing devices and provides an innovative approach for the future implementation of on-chip optical memories.展开更多
Water monitoring,environmental analysis,cell culture stability,and biomedical applications require precise pH control.Traditional methods,such as pH strips and meters,have limitations:pH strips lack precision,whereas ...Water monitoring,environmental analysis,cell culture stability,and biomedical applications require precise pH control.Traditional methods,such as pH strips and meters,have limitations:pH strips lack precision,whereas electrochemical meters,although more accurate,are fragile,prone to drift,and unsuitable for small volumes.In this paper,we propose a method for the optical detection of pH based on a multiplexed sensor with 4D microcavities fabricated via two-photon polymerization.This approach employs pH-triggered reversible variations in microresonator geometry and integrates hundreds of dual optically coupled 4D microcavities to achieve the detection limit of 0.003 pH units.The proposed solution is a clear example of the use-case-oriented application of two-photon polymerized structures of high optical quality.Owing to the benefits of the multiplexed imaging platform,the dual 4D microresonators can be integrated with other microresonator types for pH-corrected biochemical studies.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
We demonstrate high-quality(intrinsic Q factor∼2.8×106)racetrack microresonators fabricated on lithium niobate thin film with a free spectral range(FSR)of∼86 pm.By integrating microelectrodes alongside the two ...We demonstrate high-quality(intrinsic Q factor∼2.8×106)racetrack microresonators fabricated on lithium niobate thin film with a free spectral range(FSR)of∼86 pm.By integrating microelectrodes alongside the two straight arms of the racetrack resonator,the resonance wavelength around 1550 nm can be red shifted by 92 pm when the electric voltage is raised from−100 V to 100 V.The microresonators with the tuning range spanning over a full FSR are fabricated using photolithography assisted chemo-mechanical etching.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
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
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
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
Laser frequency microcombs provide a series of equidistant,coherent frequency markers across a broad spectrum,enabling advancements in laser spectroscopy,dense optical communications,precision distance metrology,and a...Laser frequency microcombs provide a series of equidistant,coherent frequency markers across a broad spectrum,enabling advancements in laser spectroscopy,dense optical communications,precision distance metrology,and astronomy.Here,we design and fabricate silicon nitride,dispersion-managed microresonators that effectively suppress avoided-mode crossings and achieve close-to-zero averaged dispersion.Both the stochastic noise and mode-locking dynamics of the resonator are numerically and experimentally investigated.First,we experimentally demonstrate thermally stabilized microcomb formation in the microresonator across different mode-locked states,showing negligible center frequency shifts and a broad frequency bandwidth.Next,we characterize the femtosecond timing jitter of the microcombs,supported by precise metrology of the timing phase and relative intensity noise.For the single-soliton state,we report a relative intensity noise of−153.2 dB∕Hz,close to the shot-noise limit,and a quantum-noise–limited timing jitter power spectral density of 0.4 as 2∕Hz at a 100 kHz offset frequency,measured using a self-heterodyne linear interferometer.In addition,we achieve an integrated timing jitter of 1.7 fs±0.07 fs,measured from 10 kHz to 1 MHz.Measuring and understanding these fundamental noise parameters in high clock rate frequency microcombs is critical for advancing soliton physics and enabling new applications in precision metrology.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
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
Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2....Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2.2 eV)and strong light-matter interactions.Unfortunately,their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response.Here,we report the triangular Sb_(2)O_(3) microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe_(2) crystal via coexisting Fabry-Perot and whispering gallery type resonances.As an example of demonstration,1L WSe_(2) crystal coupled to Sb_(2)O_(3) microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared(NIR)one of more than 50%.For application of 1L WSe_(2) in photodetection,incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by~10^(4) order and expanded NIR one of more than 400 mA·W^(-1).Similar results have been observed in the other 1L W(Mo)dichalcogenides coupled to Sb2O3 microresonators.This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.展开更多
The mode characteristics are investigated for the rectangular microresonators with an output waveguide connected to the midpoint of the long side for wide and continuous wavelength tuning. Through adjusting the aspect...The mode characteristics are investigated for the rectangular microresonators with an output waveguide connected to the midpoint of the long side for wide and continuous wavelength tuning. Through adjusting the aspect ratio of the rectangular microresonator, the mode Q factors can be greatly enhanced. Furthermore, the large mode interval between the high-Q modes makes the rectangular microresonators suitable for tunable lasers. As a special case, single-mode operation is achieved with a continuous tuning range of 9.1 nm for a square microlaser with the side length of 17.8 μm and the output waveguide width of 1.8 μm.展开更多
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
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）.
文摘Optical whispering gallery mode （WGM） microresonators have attracted great attention due to their remarkable proper- ties such as extremely high quality factor, small mode volume, tight confinement of modes, and strong evanescent field. All these properties of WGM microresonators have ensured their great potentials for applications, such as physical sen- sors, bio/chemical sensors and microlasers. In this mini-review, the key parameters and coupling conditions of WGM microresonators are firstly introduced. The geometries of WGM optical microcavities are presented based on their fabri- cation methods. This is followed by the discussion on the state-of-the-art applications of WGM microresonators in sen- sors and microlasers.
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 Key Research and Development Program of China (2023YFB3906401, 2021YFA1400803)National Natural Science Foundation of China (12341403,12293054, 92463304, 12341402)+2 种基金Fundamental Research Funds for the Central Universities (021314380260)Zhangjiang LaboratoryNatural Science Foundation of Jiangsu Province (BK20221440)。
文摘Chip-based optical microresonators with ultra-high Q-factors are becoming increasingly important to a variety of applications. However, the losses of on-chip microresonators with the highest Q-factor reported in the past are still far from their material absorption limits. Here, we demonstrate an on-chip silica microresonator that has approached the absorption limit of the state-of-the-art material on chip, realizing, to our knowledge, record intrinsic Q-factors exceeding 3 billion at both 1560 nm and 1064 nm. This fact is corroborated by photo-thermal spectroscopy measurements. Especially, compared with the standard optical fibers, its corresponding optical losses are only 38.4 times and 7.7 times higher at the wavelengths of 1560 nm and 1064 nm, respectively.To exhibit the performance of such fabricated microresonator, we achieve a record-low optical parametric oscillation threshold(31.9 μW) for millimeter-sized microresonators and generate a single-soliton microcomb with a record-low pump power of 220.2 μW for all soliton microcombs realized thus far.
基金Max-Planck-GesellschaftH2020 European Research Council(756966)The Chinese University of Hong Kong,Shenzhen(UDF01003527)。
文摘With the rapid development of the Internet of Things and big data,integrated optical switches are gaining prominence for applications in on-chip optical computing,optical memories,and optical communications.Here,we propose a novel approach for on-chip optical switches by utilizing the nonlinear optical Kerr effect induced spontaneous symmetry breaking(SSB),which leads to two distinct states of counterpropagating light in ring resonators.This technique is based on our first experimental observation of on-chip symmetry breaking in a high-Q(9.4×10~6)silicon nitride resonator with a measured SSB threshold power of approximately 3.9 mW.We further explore the influence of varying pump powers and frequency detunings on the performance of SSB-induced optical switches.Our work provides insights into the development of new types of photonic data processing devices and provides an innovative approach for the future implementation of on-chip optical memories.
基金the German Federal Ministry for Research and Education(BMBF)for partially funding this work under the VIP+-Programme in the project IntellOSS,03VP08220.
文摘Water monitoring,environmental analysis,cell culture stability,and biomedical applications require precise pH control.Traditional methods,such as pH strips and meters,have limitations:pH strips lack precision,whereas electrochemical meters,although more accurate,are fragile,prone to drift,and unsuitable for small volumes.In this paper,we propose a method for the optical detection of pH based on a multiplexed sensor with 4D microcavities fabricated via two-photon polymerization.This approach employs pH-triggered reversible variations in microresonator geometry and integrates hundreds of dual optically coupled 4D microcavities to achieve the detection limit of 0.003 pH units.The proposed solution is a clear example of the use-case-oriented application of two-photon polymerized structures of high optical quality.Owing to the benefits of the multiplexed imaging platform,the dual 4D microresonators can be integrated with other microresonator types for pH-corrected biochemical studies.
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funded by the National Key R&D Program of China(No.2019YFA0705000)the National Natural Science Foundation of China(Nos.12004116,11874154,and 11734009)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB16030300)the Shanghai Municipal Science and Technology Major Project(No.2019SHZDZX01)the Natural Science and Engineering Research Council of Canada(NSERC)Discovery(No.RGPIN-2020-05938)。
文摘We demonstrate high-quality(intrinsic Q factor∼2.8×106)racetrack microresonators fabricated on lithium niobate thin film with a free spectral range(FSR)of∼86 pm.By integrating microelectrodes alongside the two straight arms of the racetrack resonator,the resonance wavelength around 1550 nm can be red shifted by 92 pm when the electric voltage is raised from−100 V to 100 V.The microresonators with the tuning range spanning over a full FSR are fabricated using photolithography assisted chemo-mechanical etching.
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)(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 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support from the Lawrence Livermore National Laboratory(Grant No.B622827)the National Science Foundation(Grant Nos.1824568,1810506,1741707,and 1829071)the Office of Naval Research(Grant No.N00014-16-1-2094).
文摘Laser frequency microcombs provide a series of equidistant,coherent frequency markers across a broad spectrum,enabling advancements in laser spectroscopy,dense optical communications,precision distance metrology,and astronomy.Here,we design and fabricate silicon nitride,dispersion-managed microresonators that effectively suppress avoided-mode crossings and achieve close-to-zero averaged dispersion.Both the stochastic noise and mode-locking dynamics of the resonator are numerically and experimentally investigated.First,we experimentally demonstrate thermally stabilized microcomb formation in the microresonator across different mode-locked states,showing negligible center frequency shifts and a broad frequency bandwidth.Next,we characterize the femtosecond timing jitter of the microcombs,supported by precise metrology of the timing phase and relative intensity noise.For the single-soliton state,we report a relative intensity noise of−153.2 dB∕Hz,close to the shot-noise limit,and a quantum-noise–limited timing jitter power spectral density of 0.4 as 2∕Hz at a 100 kHz offset frequency,measured using a self-heterodyne linear interferometer.In addition,we achieve an integrated timing jitter of 1.7 fs±0.07 fs,measured from 10 kHz to 1 MHz.Measuring and understanding these fundamental noise parameters in high clock rate frequency microcombs is critical for advancing soliton physics and enabling new applications in precision metrology.
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This work is supported by the National Natural Science Foundation of China(Nos.51732010,5197228051801175),and Natural Science Foundation of Hebei Province(No.E2019203233).
文摘Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2.2 eV)and strong light-matter interactions.Unfortunately,their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response.Here,we report the triangular Sb_(2)O_(3) microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe_(2) crystal via coexisting Fabry-Perot and whispering gallery type resonances.As an example of demonstration,1L WSe_(2) crystal coupled to Sb_(2)O_(3) microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared(NIR)one of more than 50%.For application of 1L WSe_(2) in photodetection,incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by~10^(4) order and expanded NIR one of more than 400 mA·W^(-1).Similar results have been observed in the other 1L W(Mo)dichalcogenides coupled to Sb2O3 microresonators.This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.
文摘The mode characteristics are investigated for the rectangular microresonators with an output waveguide connected to the midpoint of the long side for wide and continuous wavelength tuning. Through adjusting the aspect ratio of the rectangular microresonator, the mode Q factors can be greatly enhanced. Furthermore, the large mode interval between the high-Q modes makes the rectangular microresonators suitable for tunable lasers. As a special case, single-mode operation is achieved with a continuous tuning range of 9.1 nm for a square microlaser with the side length of 17.8 μm and the output waveguide width of 1.8 μm.
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.
