Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated thr...Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated through depositing ZnO on patterned silicon on an insulator(SOI)substrate.The cavity structure,morphology,and photoluminescence(PL)properties are studied systematically.The cavity shows a well-defined circular structure with oxygen vacancies.Under the synergistic action of surface tension and stress,the ZnO microdisk shows a unique toroid structure with a high sidewall surface finish.The ZnO microcavity(8μm in diameter)shows optically pumped whispering gallery modes(WGMs)lasing in the ultraviolet region with a Q factor exceeding 1300.More interestingly,the quality of the toroid ZnO microdisk cavity is high enough to support the bandgap renormalization(BGR)phenomenon.With the increasing pumping power,the lasing spectra will be modulated.The lasing spectrum undergoes a Burstein-Moss(BM)effect-induced blueshift and an electron-hole plasma(EHP)effect-induced redshift.展开更多
Utilizing a high-Q microdisk resonator （MDR） on a single silicon-on-insulator （SOI） chip, a compact microwave photonic filter （MPF） with a continuously tunable central frequency is proposed and experimentally de...Utilizing a high-Q microdisk resonator （MDR） on a single silicon-on-insulator （SOI） chip, a compact microwave photonic filter （MPF） with a continuously tunable central frequency is proposed and experimentally demonstrated. Assisted by the optical single side-band （OSSB） modulation, the optical frequency response of the MDR is mapped to the microwave frequency response to form an MPF with a continuously tunable central frequency and a narrow 3-dB bandwidth. In the experiment, using an MDR with a compact size of 20×20 μm^2 and a high Q factor of 1.07×10^5, we obtain a compact MPF with a high rejection ratio of about 40 dB, a 3-dB bandwidth of about 2 GHz, and a frequency tuning range larger than 12 GHz. Our approach may allow the implementation of very compact, low-cost, low-consumption, and integrated notch MPF in a silicon chip.展开更多
The transmission equation of microdisk resonator is obtained by the transfer matrix method.The physical model is built and the electric field distribution,output spectrum and phase of the microdisk resonator are simul...The transmission equation of microdisk resonator is obtained by the transfer matrix method.The physical model is built and the electric field distribution,output spectrum and phase of the microdisk resonator are simulated by three-dimensional finite element software.The influence of the structural parameters on transmission characteristics and the temperature sensing property of the microdisk resonator are studied deeply.The results show that the output spectrum will change significantly with the distance between the microdisk and the straight waveguide within a certain range but there is no apparent change in the phase of the output port.The extinction ratio and maxima sensitivity of the device will reach 30 dB and 45 pm/℃,respectively.Microdisk has higher integration,higher quality factor and wider free spectral range compared with common microring resonator.展开更多
Based on the theories of conventional electrodes, as well as the properties of microdisk electrode, the i-E equations for chronoamperometry at disk microelectrode for reversible, quasi-reversible and irreversible syst...Based on the theories of conventional electrodes, as well as the properties of microdisk electrode, the i-E equations for chronoamperometry at disk microelectrode for reversible, quasi-reversible and irreversible systems are derived. Steady-state voltammograms for the oxidation of [Fe(CN)6]4- , Fe2+ and ascorbic acid were measured at a series of microdisk electrodes with different radii. The conventional log-plot shows that oxidations of [Fe(CN)6]4- and ascorbic acid are reversible and totally irreversible, respectively, but the oxidation of Fe2+ is reversible at larger radius microdisk electrodes and quasi-reversible at smaller radius microdisk electrodes. The application of the log-plot to the voltammograms yielded a straight line, its slope allows us to evaluate the charge transfer coefficient and the intercept gives values of the electron transfer rate constant.展开更多
Resonance effects caused by the photon-electron interaction are a focus of attention in semiconductor optoelectronics,as they are able to increase the efficiency of emission.GaN-on-silicon microdisks can provide a per...Resonance effects caused by the photon-electron interaction are a focus of attention in semiconductor optoelectronics,as they are able to increase the efficiency of emission.GaN-on-silicon microdisks can provide a perfect cavity structure for such resonance to occur.Here we report GaN-based microdisks with different diameters,based on a standard blue LED wafer on a Si substrate.A confocal photoluminescence spectroscopy is performed to analyze the properties of all microdisks.Then,we systematically study the effects of radial modes and axial modes of these microdisks on photon-electron coupling efficiency by using three-dimensional finite-difference time-domain simulations.For thick microdisks,photon-electron coupling efficiency is found to greatly depend on the distributions of both the radial modes and the axial modes,and the inclined sidewalls make significant influences on the axial mode distributions.These results are important for realization of high-efficiency resonant emission in GaN-based microcavity devices.展开更多
A multiple-wavelength GaInAsP/InP microlaser with microdisk radiuses from 10 m to 10.6 m laterally coupled into a bus waveguide are fabricated by standard photolithygraphy and inductively coupled-plasma (ICP) etching ...A multiple-wavelength GaInAsP/InP microlaser with microdisk radiuses from 10 m to 10.6 m laterally coupled into a bus waveguide are fabricated by standard photolithygraphy and inductively coupled-plasma (ICP) etching techniques. The lasing wavelengths are 1533 nm, 1541 nm, 1551 nm and 1555 nm at the CW injection current of 10 mA for the four microlasers. The proposed multiple-microlaser array would be useful for realizing compact wavelength division multiplexing (WDM) light source for optical interconnects.展开更多
Mid-infrared microcavity lasers have important applications in biosensing,mid-infrared spectroscopy,and environmental monitoring.However,the low output power of existing mid-infrared microcavity lasers hinders their p...Mid-infrared microcavity lasers have important applications in biosensing,mid-infrared spectroscopy,and environmental monitoring.However,the low output power of existing mid-infrared microcavity lasers hinders their practical use.This drawback is attributed to the insufficient laser gain medium,which limits the development of mid-infrared whispering-gallerymode(WGM)lasers.To address this issue,we have employed ion implantation-enhanced etching to fabricate Tm:YAG thin films as effective gain media for mid-infrared WGM lasers.The Tm:YAG thin film,with a thickness of 2μm,exhibits excellent fluorescence characteristics.Subsequently,the Tm:YAG thin film is processed using focused ion beam to form microdisks with a diameter of 30μm.Under 785 nm laser pumping,the maximum output power of the Tm:YAG microdisk at 2023.1 nm is229μW,with a slope efficiency of 2.9%.This work demonstrates the outstanding potential of Tm:YAG as a mid-infrared laser gain medium,providing a new option for the development of mid-infrared lasers.展开更多
We demonstrate single-mode microdisk lasers in the telecom band with ultralow thresholds on erbium-ytterbium co-doped thin-film lithium niobate(TFLN).The active microdisk was fabricated with high-Q factors by photolit...We demonstrate single-mode microdisk lasers in the telecom band with ultralow thresholds on erbium-ytterbium co-doped thin-film lithium niobate(TFLN).The active microdisk was fabricated with high-Q factors by photolithography-assisted chemomechanical etching.Thanks to the erbium-ytterbium co-doping providing high optical gain,the ultralow loss nanostructuring,and the excitation of high-Q coherent polygon modes,which suppresses multimode lasing and allows high spatial mode overlap between pump and lasing modes,single-mode laser emission operating at 1530 nm wavelength was observed with an ultralow threshold,under a 980-nm-band optical pump.The threshold was measured as low as 1μW,which is one order of magnitude smaller than the best results previously reported in single-mode active TFLN microlasers.The conversion efficiency reaches 4.06×10^(-3),which is also the highest value reported in single-mode active TFLN microlasers.展开更多
This paper describes the specially designed geometry of a dry-etched large-wedge-angle silica microdisk resonator that enables anomalous dispersion in the 780 nm wavelength regime. This anomalous dispersion occurs nat...This paper describes the specially designed geometry of a dry-etched large-wedge-angle silica microdisk resonator that enables anomalous dispersion in the 780 nm wavelength regime. This anomalous dispersion occurs naturally without the use of a mode-hybridization technique to control the geometrical dispersion. By fabricating a1-μm-thick silica microdisk with a wedge angle as large as 56° and an optical Q-factor larger than 107, we achieve a visible Kerr comb that covers the wavelength interval of 700–897 nm. The wide optical frequency range and the closeness to the clock transition at 698 nm of 87 Sr atoms make our visible comb a potentially useful tool in optical atomic clock applications.展开更多
We report an electro-optically(EO)tunable microdisk laser fabricated on the erbium(Er^(3+))-doped lithium niobate on insulator(LNOI) substrate.By applying a variable voltage on a pair of integrated chromium(Cr) microe...We report an electro-optically(EO)tunable microdisk laser fabricated on the erbium(Er^(3+))-doped lithium niobate on insulator(LNOI) substrate.By applying a variable voltage on a pair of integrated chromium(Cr) microelectrodes fabricated near the LNOI microdisk,electro-optic modulation with an effective resonance-frequency tuning rate of 2.6 GHz/100 V has been achieved.This gives rise to a tuning range of 45 pm when the electric voltage is varied between-200 V and 200 V.展开更多
Micro-and nanodisk lasers have emerged as promising optical sources and probes for on-chip and free-space applications.However,the randomness in disk diameter introduced by standard nanofabrication makes it challengin...Micro-and nanodisk lasers have emerged as promising optical sources and probes for on-chip and free-space applications.However,the randomness in disk diameter introduced by standard nanofabrication makes it challenging to obtain deterministic wavelengths.To address this,we developed a photoelectrochemical(PEC)etching-based technique that enables us to precisely tune the lasing wavelength with subnanometer accuracy.We examined the PEC mechanism and compound semiconductor etching rate in diluted sulfuric acid solution.Using this technique,we produced microlasers on a chip and isolated particles with distinct lasing wavelengths.These precisely tuned disk lasers were then used to tag cells in culture.Our results demonstrate that this scalable technique can be used to produce groups of lasers with precise emission wavelengths for various nanophotonic and biomedical applications.展开更多
We report the first observation, to the best of our knowledge, of sum-frequency generation in on-chip lithium niobate microdisk resonators. The sum-frequency signal in the 780 nm band, distinct in wavelength from seco...We report the first observation, to the best of our knowledge, of sum-frequency generation in on-chip lithium niobate microdisk resonators. The sum-frequency signal in the 780 nm band, distinct in wavelength from secondharmonic signals, was obtained in lithium niobate microresonators under the pump of two individual 1550 nm band lasers. The sum-frequency conversion efficiency was measured to be 1.4 × 10^(-7) mW^(-1). The dependence of the intensities of the nonlinear signals on the total pump power and the wavelength of one pump laser was investigated while fixing the wavelength of the other. This work paves the way for applications of on-chip lithium niobate microdisk resonators ranging from infrared single-photon detection to infrared spectroscopy.展开更多
We experimentally demonstrate high optical quality factor silica microdisk resonators on a silicon chip with large wedge angles by reactive ion etching. For 2-μm-thick microresonators, we have achieved wedge angles o...We experimentally demonstrate high optical quality factor silica microdisk resonators on a silicon chip with large wedge angles by reactive ion etching. For 2-μm-thick microresonators, we have achieved wedge angles of 59°, 63°,70°, and 79° with optical quality factors of 2.4 × 10~7, 8.1 × 10~6, 5.9 × 10~6, and 7.4 × 10~6, respectively, from ～80 μm diameter microresonators in the 1550 nm wavelength band. Also, for 1-μm-thick microresonators, we have obtained an optical quality factor of 7.3 × 10~6 with a wedge angle of 74°.展开更多
The method for batch continuous production of polymerized cholesteric liquid crystal(PCLC) microdisks based on centrifugal microfluidics was proposed. The prototype centrifugal microfluidic chip was fabricated by the ...The method for batch continuous production of polymerized cholesteric liquid crystal(PCLC) microdisks based on centrifugal microfluidics was proposed. The prototype centrifugal microfluidic chip was fabricated by the wetetching technique with a series of ladder-like concentric ring channels whose depths decrease radially. Two types of dye-doped PCLC microdisks with different doping procedures were generated by this method, the tunable lasing properties were characterized, and corresponding potential applications in a micro-cavity laser and optical barcode were demonstrated. The method is also applicable to a broad range of other polymerized materials.展开更多
A novel slotted optical microdisk resonator, which significantly enhances light–matter interaction and provides a promising approach for increasing the sensitivity of sensors, is theoretically and numerically investi...A novel slotted optical microdisk resonator, which significantly enhances light–matter interaction and provides a promising approach for increasing the sensitivity of sensors, is theoretically and numerically investigated. In this slotted resonator, the mode splitting is generated due to reflection of the slot. Remarkably, effects of the slot width and angular position on the mode splitting are mainly studied. The results reveal that the mode splitting is a second function of the slot width, and the maximum mode splitting induced by the slot deformation is achieved with 2.7853 × 10~9Hz∕nm. Therefore, the slotted resonator is an excellent candidate for pressure and force sensing. Besides, the influence of the slot angular position on the mode splitting is a cosine curve with the highest sensitivity of 1.23 × 10^(11)Hz∕deg; thus, the optical characteristic demonstrates that the slotted resonator can be used for inertial measurements.展开更多
An analytical expression describing voltammetric behaviors responses at microdisk electrode for various diffusion conditions and degrees of reversibility is reported in this paper. Results of theoretical calculation m...An analytical expression describing voltammetric behaviors responses at microdisk electrode for various diffusion conditions and degrees of reversibility is reported in this paper. Results of theoretical calculation made it possible to use cyclic voltammetry to evaluate heterogeneous rate constants under intermediate diffusion conditions. At relatively low scan rate, the distortion of current-voltage can be reduced due to small iR drops and charging current. The effects of transfer coefficient, alpha, kinetic parameter, lambda(=k(0)r/4D), and switching potential, xi(8), on potential peak separation are discussed in detail. The relationship obtained in this paper between potential peak separation and lambda is in good agreement with that in Ref. 14, whose authors have got their results by using digital simulation technique. After the experiment of Fe(CN)(6)(4-) oxidation, k(0) and alpha were obtained by the theory of this paper. The result agrees with that in Ref. 19.展开更多
A three electrode-measurement unit with 33 microdisk electrode-array (MDA) as working electrode was constructed by lithograpy. Its electrochemical behavior was observed. The results of the oxidation of ferrocene in CH...A three electrode-measurement unit with 33 microdisk electrode-array (MDA) as working electrode was constructed by lithograpy. Its electrochemical behavior was observed. The results of the oxidation of ferrocene in CH3CN-H2O mixed media demonstrate that high quality electrochemical data for the system without supporting electrolyte can be achieved with the MDA unit constructed in the present work.展开更多
The III-nitride semiconductor microdisk laser exhibits high quality factor and low excitation threshold with broad development potential in the field of nanophotonics such as nanoscale light-emitting devices and on-ch...The III-nitride semiconductor microdisk laser exhibits high quality factor and low excitation threshold with broad development potential in the field of nanophotonics such as nanoscale light-emitting devices and on-chip optical integration.So far,many works have been focused on process synthesis and nanostructural design of microdisk lasers.Nevertheless,there are still some limitations in the existing optical resonance mode which is an important internal influence factor for lasing characteristics.In this work,a new double-triangular whispering-gallery mode(D3-WGM)lasing from a hexagonal GaN microdisk with a high quality(Q)factor of 3049 and an excitation threshold of around 11.5μW has been experimentally demonstrated.In addition,the optical properties of hexagonal-WGM(6-WGM),triangular-WGM(3-WGM)and D3-WGM lasing from microdisk are explored by numerical calculation and Comsol simulation.These results confirm that the D3-WGM lasing has its own significant performance advantages,namely high Q factor and easy light emission.Based on this novel laser mode characteristic,microcavity lasers are expected to be further developed and applied in the field of nanophotonics.展开更多
There are significant differences in the extent of impurity incorporation on different crystallographic directions of GaN microstructures,and the impurity-related deep energy level behavior will have a significant imp...There are significant differences in the extent of impurity incorporation on different crystallographic directions of GaN microstructures,and the impurity-related deep energy level behavior will have a significant impact on device performance.However,a comprehensive understanding of the effect of lateral growth on device performance has not been achieved due to the lack of comprehensive spatial distribution characterization of the optical behavior and impurity incorporation in GaN microstructures.We present a comprehensive study of the optical behavior and growth mechanism of self-assembled GaN microdisks using nanoscale spatially resolved cathodoluminescence(CL)mapping.We have found a clear growth orientation-dependent optical behavior of the lateral and vertical growth sectors of self-assembled GaN microcrystals.The lateral growth sector,i.e.,the{101¯1}-growth sector,forms six side facets of the microdisk and shows significant near-bandgap emission(NBE)and weak deep energy level luminescence.Cavity effect enhanced emission was found for the first time in such a truncated hexagonal Na-flux GaN microdisk system with an ultra-smooth surface(Ra<0.7 nm)and low stress.The self-assembled microdisk shows significant ultraviolet(UV)lasing action(main lasing peak wavelength 370.9 nm,quality factor 1278,threshold 6×10^(4)μJ/cm^(2))under pulsed optical pumping.We believe that the appearance of UV lasing action may be related to the light limitation on the six side facets of the lateral growth of the GaN microdisk,the high structural quality,the low content of deep energy level defects,the low surface roughness,and the low stress.展开更多
In this work,on-chip three-dimensional(3D)photonic integrated optical sources based on active fluorescent polymer waveguide microdisks are proposed for light display application.Fluorescent green and red oligomers wit...In this work,on-chip three-dimensional(3D)photonic integrated optical sources based on active fluorescent polymer waveguide microdisks are proposed for light display application.Fluorescent green and red oligomers with high-efficiency photoluminescence are doped into epoxy crosslinking SU-8 polymer as the waveguide gain medium.The microdisk-based on-chip optically pumping light sources are designed and fabricated using the organic functionalized materials by direct UV written process.The promising stacking dual-microdisk structures with double gain layers could provide white signal light source generated perpendicular to the chip,and green signal light source stimulated in the chip.The approach could realize the monolithically on-chip assembled vertical and horizontal bright emitters.The optical pumping threshold power is obtained as 50 mW with continuous-wave(CW)pumping.The average gain coefficient of a white light source is measured by vertical fiber coupling as 112 dB/W,and that of green light source by horizontal fiber coupling as 137 dB/W,respectively.The rising and falling response time of the on-chip optical sources are 60 and 80μs under modulating pulsed pumping.This technique is very promising for achieving 3D integrated light display application,including photonic circuits and optical information encryption.展开更多
文摘Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated through depositing ZnO on patterned silicon on an insulator(SOI)substrate.The cavity structure,morphology,and photoluminescence(PL)properties are studied systematically.The cavity shows a well-defined circular structure with oxygen vacancies.Under the synergistic action of surface tension and stress,the ZnO microdisk shows a unique toroid structure with a high sidewall surface finish.The ZnO microcavity(8μm in diameter)shows optically pumped whispering gallery modes(WGMs)lasing in the ultraviolet region with a Q factor exceeding 1300.More interestingly,the quality of the toroid ZnO microdisk cavity is high enough to support the bandgap renormalization(BGR)phenomenon.With the increasing pumping power,the lasing spectra will be modulated.The lasing spectrum undergoes a Burstein-Moss(BM)effect-induced blueshift and an electron-hole plasma(EHP)effect-induced redshift.
基金supported by the National Basic Research Program of China(Grant No.2011CB301704)the Program for New Century Excellent Talents in Ministry of Education of China(Grant No.NCET-11-0168)+1 种基金the Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No.201139)the National Natural Science Foundation of China(Grant Nos.60901006 and 11174096)
文摘Utilizing a high-Q microdisk resonator （MDR） on a single silicon-on-insulator （SOI） chip, a compact microwave photonic filter （MPF） with a continuously tunable central frequency is proposed and experimentally demonstrated. Assisted by the optical single side-band （OSSB） modulation, the optical frequency response of the MDR is mapped to the microwave frequency response to form an MPF with a continuously tunable central frequency and a narrow 3-dB bandwidth. In the experiment, using an MDR with a compact size of 20×20 μm^2 and a high Q factor of 1.07×10^5, we obtain a compact MPF with a high rejection ratio of about 40 dB, a 3-dB bandwidth of about 2 GHz, and a frequency tuning range larger than 12 GHz. Our approach may allow the implementation of very compact, low-cost, low-consumption, and integrated notch MPF in a silicon chip.
基金National Natural Science Foundation of China(No.61762057)Natural Science Foundation of Gansu Province(No.18JR3RA123)。
文摘The transmission equation of microdisk resonator is obtained by the transfer matrix method.The physical model is built and the electric field distribution,output spectrum and phase of the microdisk resonator are simulated by three-dimensional finite element software.The influence of the structural parameters on transmission characteristics and the temperature sensing property of the microdisk resonator are studied deeply.The results show that the output spectrum will change significantly with the distance between the microdisk and the straight waveguide within a certain range but there is no apparent change in the phase of the output port.The extinction ratio and maxima sensitivity of the device will reach 30 dB and 45 pm/℃,respectively.Microdisk has higher integration,higher quality factor and wider free spectral range compared with common microring resonator.
基金Supported by the National Natural Science Foundation of China Changchun Institute of Applied Chemistry of Chinese Academy of Sciences
文摘Based on the theories of conventional electrodes, as well as the properties of microdisk electrode, the i-E equations for chronoamperometry at disk microelectrode for reversible, quasi-reversible and irreversible systems are derived. Steady-state voltammograms for the oxidation of [Fe(CN)6]4- , Fe2+ and ascorbic acid were measured at a series of microdisk electrodes with different radii. The conventional log-plot shows that oxidations of [Fe(CN)6]4- and ascorbic acid are reversible and totally irreversible, respectively, but the oxidation of Fe2+ is reversible at larger radius microdisk electrodes and quasi-reversible at smaller radius microdisk electrodes. The application of the log-plot to the voltammograms yielded a straight line, its slope allows us to evaluate the charge transfer coefficient and the intercept gives values of the electron transfer rate constant.
基金the National Key R&D Program of China(Grant Nos.2016YFB0400102 and 2016YFB0400602)the National Natural Science Foundation of China(Grant Nos.61674076,61422401 and 51461135002)+2 种基金the Collaborative Innovation Center of Solid State Lighting and Energy-Saving Electronics,Open Fund of the State Key Laboratory on Integrated Optoelectronics(Grant No.IOSKL2017KF03)the Natural Science Foundation for Young Scientists of Jiangsu Province of China(Grant No.BK20160376)the Research Funds from NJU-Yangzhou Institute of Opto-electronics,and the Research and Development Funds from State Grid Shandong Electric Power Company and Electric Power Research Institute.
文摘Resonance effects caused by the photon-electron interaction are a focus of attention in semiconductor optoelectronics,as they are able to increase the efficiency of emission.GaN-on-silicon microdisks can provide a perfect cavity structure for such resonance to occur.Here we report GaN-based microdisks with different diameters,based on a standard blue LED wafer on a Si substrate.A confocal photoluminescence spectroscopy is performed to analyze the properties of all microdisks.Then,we systematically study the effects of radial modes and axial modes of these microdisks on photon-electron coupling efficiency by using three-dimensional finite-difference time-domain simulations.For thick microdisks,photon-electron coupling efficiency is found to greatly depend on the distributions of both the radial modes and the axial modes,and the inclined sidewalls make significant influences on the axial mode distributions.These results are important for realization of high-efficiency resonant emission in GaN-based microcavity devices.
文摘A multiple-wavelength GaInAsP/InP microlaser with microdisk radiuses from 10 m to 10.6 m laterally coupled into a bus waveguide are fabricated by standard photolithygraphy and inductively coupled-plasma (ICP) etching techniques. The lasing wavelengths are 1533 nm, 1541 nm, 1551 nm and 1555 nm at the CW injection current of 10 mA for the four microlasers. The proposed multiple-microlaser array would be useful for realizing compact wavelength division multiplexing (WDM) light source for optical interconnects.
基金supported by the National Natural Science Foundation of China(Grant No.12122508)supported by State Key Laboratory of Nuclear Physics and Technology,Peking University(Grant No.NPT2023KFJ11)。
文摘Mid-infrared microcavity lasers have important applications in biosensing,mid-infrared spectroscopy,and environmental monitoring.However,the low output power of existing mid-infrared microcavity lasers hinders their practical use.This drawback is attributed to the insufficient laser gain medium,which limits the development of mid-infrared whispering-gallerymode(WGM)lasers.To address this issue,we have employed ion implantation-enhanced etching to fabricate Tm:YAG thin films as effective gain media for mid-infrared WGM lasers.The Tm:YAG thin film,with a thickness of 2μm,exhibits excellent fluorescence characteristics.Subsequently,the Tm:YAG thin film is processed using focused ion beam to form microdisks with a diameter of 30μm.Under 785 nm laser pumping,the maximum output power of the Tm:YAG microdisk at 2023.1 nm is229μW,with a slope efficiency of 2.9%.This work demonstrates the outstanding potential of Tm:YAG as a mid-infrared laser gain medium,providing a new option for the development of mid-infrared lasers.
基金supported by the National Key R&D Program of China(Nos.2019YFA0705000,2022YFA1404600,and 2022YFA1205100)the National Natural Science Foundation of China(NSFC)(Nos.62122079,12192251,62235019,12334014,12134001,12104159,and 11933005)+4 种基金the Innovation Program for Quantum Science and Technology(No.2021ZD0301403)the Shanghai Municipal Science and Technology Major Project(No.2019SHZDZX01)the Science and Technology Commission of Shanghai Municipality(Nos.21DZ1101500 and 23ZR1481800)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020249)the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(No.2023nmc005)。
文摘We demonstrate single-mode microdisk lasers in the telecom band with ultralow thresholds on erbium-ytterbium co-doped thin-film lithium niobate(TFLN).The active microdisk was fabricated with high-Q factors by photolithography-assisted chemomechanical etching.Thanks to the erbium-ytterbium co-doping providing high optical gain,the ultralow loss nanostructuring,and the excitation of high-Q coherent polygon modes,which suppresses multimode lasing and allows high spatial mode overlap between pump and lasing modes,single-mode laser emission operating at 1530 nm wavelength was observed with an ultralow threshold,under a 980-nm-band optical pump.The threshold was measured as low as 1μW,which is one order of magnitude smaller than the best results previously reported in single-mode active TFLN microlasers.The conversion efficiency reaches 4.06×10^(-3),which is also the highest value reported in single-mode active TFLN microlasers.
基金National Key R&D Program of China(2016YFA0302500,2017YFA0303703)National Natural Science Foundation of China(NSFC)(61435007,11574144,11621091,61475099)
文摘This paper describes the specially designed geometry of a dry-etched large-wedge-angle silica microdisk resonator that enables anomalous dispersion in the 780 nm wavelength regime. This anomalous dispersion occurs naturally without the use of a mode-hybridization technique to control the geometrical dispersion. By fabricating a1-μm-thick silica microdisk with a wedge angle as large as 56° and an optical Q-factor larger than 107, we achieve a visible Kerr comb that covers the wavelength interval of 700–897 nm. The wide optical frequency range and the closeness to the clock transition at 698 nm of 87 Sr atoms make our visible comb a potentially useful tool in optical atomic clock applications.
基金supported by the National Key R&D Program of China (No. 2019YFA0705000)National Natural Science Foundation of China (Nos. 12004116, 11874154, 11734009, 11933005, 11874060, and 61991444)+1 种基金Shanghai Municipal Science and Technology Major Project (No. HZDZX01)Fundamental Research Funds for the Central Universities, and Shanghai Sailing Program (No. 1410400)
文摘We report an electro-optically(EO)tunable microdisk laser fabricated on the erbium(Er^(3+))-doped lithium niobate on insulator(LNOI) substrate.By applying a variable voltage on a pair of integrated chromium(Cr) microelectrodes fabricated near the LNOI microdisk,electro-optic modulation with an effective resonance-frequency tuning rate of 2.6 GHz/100 V has been achieved.This gives rise to a tuning range of 45 pm when the electric voltage is varied between-200 V and 200 V.
基金supported by the US National Institutes of Health research grants (DP1-OD022296, R01-EB033155, R01-EB034687)
文摘Micro-and nanodisk lasers have emerged as promising optical sources and probes for on-chip and free-space applications.However,the randomness in disk diameter introduced by standard nanofabrication makes it challenging to obtain deterministic wavelengths.To address this,we developed a photoelectrochemical(PEC)etching-based technique that enables us to precisely tune the lasing wavelength with subnanometer accuracy.We examined the PEC mechanism and compound semiconductor etching rate in diluted sulfuric acid solution.Using this technique,we produced microlasers on a chip and isolated particles with distinct lasing wavelengths.These precisely tuned disk lasers were then used to tag cells in culture.Our results demonstrate that this scalable technique can be used to produce groups of lasers with precise emission wavelengths for various nanophotonic and biomedical applications.
基金National Natural Science Foundation of China(NSFC)(11374165,11674181,11674184,61475077)Ministry of Science and Technology of the People’s Republic of China(MOST)(2013CB328702)+1 种基金Ministry of Education of the People’s Republic of China(MOE)(B07013)PCSIRT(IRT_13R29)
文摘We report the first observation, to the best of our knowledge, of sum-frequency generation in on-chip lithium niobate microdisk resonators. The sum-frequency signal in the 780 nm band, distinct in wavelength from secondharmonic signals, was obtained in lithium niobate microresonators under the pump of two individual 1550 nm band lasers. The sum-frequency conversion efficiency was measured to be 1.4 × 10^(-7) mW^(-1). The dependence of the intensities of the nonlinear signals on the total pump power and the wavelength of one pump laser was investigated while fixing the wavelength of the other. This work paves the way for applications of on-chip lithium niobate microdisk resonators ranging from infrared single-photon detection to infrared spectroscopy.
基金supported by the National Basic Research Program of China (Nos. 2012CB921804 and 2011CBA00205)the National Natural Science Foundation of China (Nos. 61435007 and 11321063)
文摘We experimentally demonstrate high optical quality factor silica microdisk resonators on a silicon chip with large wedge angles by reactive ion etching. For 2-μm-thick microresonators, we have achieved wedge angles of 59°, 63°,70°, and 79° with optical quality factors of 2.4 × 10~7, 8.1 × 10~6, 5.9 × 10~6, and 7.4 × 10~6, respectively, from ～80 μm diameter microresonators in the 1550 nm wavelength band. Also, for 1-μm-thick microresonators, we have obtained an optical quality factor of 7.3 × 10~6 with a wedge angle of 74°.
基金supported by the National Natural Science Foundation of China(NSFC)(No.61675172)the Natural Science Foundation of Fujian Province,China(No.2017J01124)。
文摘The method for batch continuous production of polymerized cholesteric liquid crystal(PCLC) microdisks based on centrifugal microfluidics was proposed. The prototype centrifugal microfluidic chip was fabricated by the wetetching technique with a series of ladder-like concentric ring channels whose depths decrease radially. Two types of dye-doped PCLC microdisks with different doping procedures were generated by this method, the tunable lasing properties were characterized, and corresponding potential applications in a micro-cavity laser and optical barcode were demonstrated. The method is also applicable to a broad range of other polymerized materials.
基金National Natural Science Foundation of China(NSFC)(61575014)Natural Science Foundation of Beijing Municipality(4162038)
文摘A novel slotted optical microdisk resonator, which significantly enhances light–matter interaction and provides a promising approach for increasing the sensitivity of sensors, is theoretically and numerically investigated. In this slotted resonator, the mode splitting is generated due to reflection of the slot. Remarkably, effects of the slot width and angular position on the mode splitting are mainly studied. The results reveal that the mode splitting is a second function of the slot width, and the maximum mode splitting induced by the slot deformation is achieved with 2.7853 × 10~9Hz∕nm. Therefore, the slotted resonator is an excellent candidate for pressure and force sensing. Besides, the influence of the slot angular position on the mode splitting is a cosine curve with the highest sensitivity of 1.23 × 10^(11)Hz∕deg; thus, the optical characteristic demonstrates that the slotted resonator can be used for inertial measurements.
基金Project supported by the National Natural Science Foundation of China.
文摘An analytical expression describing voltammetric behaviors responses at microdisk electrode for various diffusion conditions and degrees of reversibility is reported in this paper. Results of theoretical calculation made it possible to use cyclic voltammetry to evaluate heterogeneous rate constants under intermediate diffusion conditions. At relatively low scan rate, the distortion of current-voltage can be reduced due to small iR drops and charging current. The effects of transfer coefficient, alpha, kinetic parameter, lambda(=k(0)r/4D), and switching potential, xi(8), on potential peak separation are discussed in detail. The relationship obtained in this paper between potential peak separation and lambda is in good agreement with that in Ref. 14, whose authors have got their results by using digital simulation technique. After the experiment of Fe(CN)(6)(4-) oxidation, k(0) and alpha were obtained by the theory of this paper. The result agrees with that in Ref. 19.
基金Project supported by the State Key Laboratories of Transducer Technology,Chinese Academy of Sciences.
文摘A three electrode-measurement unit with 33 microdisk electrode-array (MDA) as working electrode was constructed by lithograpy. Its electrochemical behavior was observed. The results of the oxidation of ferrocene in CH3CN-H2O mixed media demonstrate that high quality electrochemical data for the system without supporting electrolyte can be achieved with the MDA unit constructed in the present work.
基金supported financially by the State Key Program of National Natural Science Foundation of China(No.61734008)the National Natural Science Foundation of China(Nos.61574097,61604170 and 61604169)+1 种基金the National Key Research and Development Program of China(Nos.2016YFA0201101 and 2017YFB0404100)the National Key Scientific Instrument and Equipment Development Project(No.11327804)。
文摘The III-nitride semiconductor microdisk laser exhibits high quality factor and low excitation threshold with broad development potential in the field of nanophotonics such as nanoscale light-emitting devices and on-chip optical integration.So far,many works have been focused on process synthesis and nanostructural design of microdisk lasers.Nevertheless,there are still some limitations in the existing optical resonance mode which is an important internal influence factor for lasing characteristics.In this work,a new double-triangular whispering-gallery mode(D3-WGM)lasing from a hexagonal GaN microdisk with a high quality(Q)factor of 3049 and an excitation threshold of around 11.5μW has been experimentally demonstrated.In addition,the optical properties of hexagonal-WGM(6-WGM),triangular-WGM(3-WGM)and D3-WGM lasing from microdisk are explored by numerical calculation and Comsol simulation.These results confirm that the D3-WGM lasing has its own significant performance advantages,namely high Q factor and easy light emission.Based on this novel laser mode characteristic,microcavity lasers are expected to be further developed and applied in the field of nanophotonics.
基金This work was supported by the National Key R&D Program of China(No.2021YFB3602000)the Fundamental Research Funds for the Central Universities(No.WK5290000003).
文摘There are significant differences in the extent of impurity incorporation on different crystallographic directions of GaN microstructures,and the impurity-related deep energy level behavior will have a significant impact on device performance.However,a comprehensive understanding of the effect of lateral growth on device performance has not been achieved due to the lack of comprehensive spatial distribution characterization of the optical behavior and impurity incorporation in GaN microstructures.We present a comprehensive study of the optical behavior and growth mechanism of self-assembled GaN microdisks using nanoscale spatially resolved cathodoluminescence(CL)mapping.We have found a clear growth orientation-dependent optical behavior of the lateral and vertical growth sectors of self-assembled GaN microcrystals.The lateral growth sector,i.e.,the{101¯1}-growth sector,forms six side facets of the microdisk and shows significant near-bandgap emission(NBE)and weak deep energy level luminescence.Cavity effect enhanced emission was found for the first time in such a truncated hexagonal Na-flux GaN microdisk system with an ultra-smooth surface(Ra<0.7 nm)and low stress.The self-assembled microdisk shows significant ultraviolet(UV)lasing action(main lasing peak wavelength 370.9 nm,quality factor 1278,threshold 6×10^(4)μJ/cm^(2))under pulsed optical pumping.We believe that the appearance of UV lasing action may be related to the light limitation on the six side facets of the lateral growth of the GaN microdisk,the high structural quality,the low content of deep energy level defects,the low surface roughness,and the low stress.
基金National Key Research and Development(R&D)Program of China(2019YFB2203001)National Natural Science Foundation of China(NSFC,No.62171195).
文摘In this work,on-chip three-dimensional(3D)photonic integrated optical sources based on active fluorescent polymer waveguide microdisks are proposed for light display application.Fluorescent green and red oligomers with high-efficiency photoluminescence are doped into epoxy crosslinking SU-8 polymer as the waveguide gain medium.The microdisk-based on-chip optically pumping light sources are designed and fabricated using the organic functionalized materials by direct UV written process.The promising stacking dual-microdisk structures with double gain layers could provide white signal light source generated perpendicular to the chip,and green signal light source stimulated in the chip.The approach could realize the monolithically on-chip assembled vertical and horizontal bright emitters.The optical pumping threshold power is obtained as 50 mW with continuous-wave(CW)pumping.The average gain coefficient of a white light source is measured by vertical fiber coupling as 112 dB/W,and that of green light source by horizontal fiber coupling as 137 dB/W,respectively.The rising and falling response time of the on-chip optical sources are 60 and 80μs under modulating pulsed pumping.This technique is very promising for achieving 3D integrated light display application,including photonic circuits and optical information encryption.
