During the last decades the whispering gallery mode based sensors have become a prominent solution for label-free sensing of various physical and chemical parameters.At the same time,the widespread utilization of the ...During the last decades the whispering gallery mode based sensors have become a prominent solution for label-free sensing of various physical and chemical parameters.At the same time,the widespread utilization of the approach is hindered by the restricted applicability of the known configurations for ambient variations quantification outside the laboratory conditions and their low affordability,where necessity on the spectrally-resolved data collection is among the main limiting factors.In this paper we demonstrate the first realization of an affordable whispering gallery mode sensor powered by deep learning and multi-resonator imaging at a fixed frequency.It has been shown that the approach enables refractive index unit(RIU)prediction with an absolute error at 3×10^(-6) level for dynamic range of the RIU variations from 0 to 2×10^(-3) with temporal resolution of several milliseconds and instrument-driven detection limit of 3×10−5.High sensing accuracy together with instrumental affordability and production simplicity places the reported detector among the most cost-effective realizations of the whispering gallery mode approach.The proposed solution is expected to have a great impact on the shift of the whole sensing paradigm away from the model-based and to the flexible self-learning solutions.展开更多
Conventionally, metallic nanostructures are used for surface-enhanced Raman spectroscopy(SERS), but recently there has been increasing interest in the enhancement of Raman scattering from dielectric substrates due to ...Conventionally, metallic nanostructures are used for surface-enhanced Raman spectroscopy(SERS), but recently there has been increasing interest in the enhancement of Raman scattering from dielectric substrates due to their improved stability and biocompatibility compared with metallic substrates. Here, we report the observation of enhanced Raman scattering from rhodamine 6 G molecules coated on silica microspheres. We excite the whispering gallery modes(WGMs) supported in the microspheres with a tapered fiber coupler for efficient WGM excitation, and the Raman enhancement can be attributed to the WGM mechanism. Strong resonance enhancement in pump laser intensity and modified Raman emission from the Purcell effect in the microsphere resonator are observed from the experiment and compared with theoretical results. A total Raman enhancement factor of 1.4 × 10~4 is observed, with contribution mostly from the enhancement in pump laser intensity. Our results show that, with an efficient pumping scheme, dielectric microspheres are a viable alternative to metallic SERS substrates.展开更多
We report the fabrication and optical characterization of spherical whispering gallery mode(WGM)resonators made from ultraviolet(UV)-curable adhesive.The fabricated microspheres have good sphericity and surface smooth...We report the fabrication and optical characterization of spherical whispering gallery mode(WGM)resonators made from ultraviolet(UV)-curable adhesive.The fabricated microspheres have good sphericity and surface smoothness,and can directly adhere to the tip of half-tapered fibers for easy manipulation.WGMs are e?ciently excited in the microsphere using an evanescent field of the tapered silica optical fibers.Resonances with quality factors of 1.3×105are observed.The dependence of wavelength shifts of WGM resonances on the input light powers shows that the resonant wavelength of the proposed microsphere resonators can be tuned thermo-optically.展开更多
In this letter,a humidity sensor is demonstrated by applying a whispering gallery mode(WGM)from a microsphere resonator onto the ZnO nanorods coated glass surface.The diameter of the microsphere was 234μm and the gla...In this letter,a humidity sensor is demonstrated by applying a whispering gallery mode(WGM)from a microsphere resonator onto the ZnO nanorods coated glass surface.The diameter of the microsphere was 234μm and the glass surface was coated with ZnO nanorods using the hydrothermal method at growth duration of 12 h.A significant response to humidity level ranging from 35%RH to 85%RH has been observed with the sensitivity of 0.0142 nm/%RH.The proposed humidity sensor has successfully employed to enhance interaction between the whispering gallery mode evanescent and surrounds analyte with the assistance of ZnO nanorods coated glass.展开更多
With the support by the National Natural Science Foundation of China,Chinese Academy of Sciences,and Ministry of Science and Technology of China,the research group led by Dr.Dong Chunhua(董春华)at the CAS Key Lab of Q...With the support by the National Natural Science Foundation of China,Chinese Academy of Sciences,and Ministry of Science and Technology of China,the research group led by Dr.Dong Chunhua(董春华)at the CAS Key Lab of Quantum Information,University of Science and Technology of China。展开更多
We show that electric field on the plane surface of truncated sphere or cylinders(so called Janus particles)have sharp resonances versus the depth of removed segment of a sphere or cylinder.These resonances are relate...We show that electric field on the plane surface of truncated sphere or cylinders(so called Janus particles)have sharp resonances versus the depth of removed segment of a sphere or cylinder.These resonances are related to the excited whispering gallery waves caused by truncation.It is a new mechanism of the field localization.Optimization of this effect for cylinders permits to reach a super resolution in the line thickness,which can be used for contact optical lithography.展开更多
Super-resolution imaging with superlens has been one of the fundamental research topics. Unfortunately, the resolution of superlens is inevitably restrained by material loss. To address the problem, we introduce the s...Super-resolution imaging with superlens has been one of the fundamental research topics. Unfortunately, the resolution of superlens is inevitably restrained by material loss. To address the problem, we introduce the solid immersion mechanism into the slab superlens and the cylindrical superlens. The proposed solid immersion slab superlens(SISSL) and the solid immersion cylindrical superlens(SICSL) can improve the resolution by converting evanescent wave to propagating wave using high refractive index materials. From the perspective of applications, the cylindrical superlens with finite cross section and the ability of magnification or demagnification has more advantages than the slab superlens. Therefore,we focus on demonstrating analytically the super-resolution imaging of SICSL. Due to the impedance mismatching caused by solid immersion mechanism, the whispering gallery modes(WGMs) are excited between SICSL and the air interface.We clarify the excitation conditions of WGMs and analyze their influence on the imaging quality of SICSL. The SISSL and SICSL may pave a way to apply in lithography technique and real-time biomolecular imaging in future.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
Optical whispering gallery microcavities with high-quality factors have shown great potential toward achieveing ultrahigh-sensitivity sensing up to a single molecule or nanoparticle, which raises a huge demand on a de...Optical whispering gallery microcavities with high-quality factors have shown great potential toward achieveing ultrahigh-sensitivity sensing up to a single molecule or nanoparticle, which raises a huge demand on a deep theoretical insight into the crucial phenomena such as the mode shift, mode splitting, and mode broadening in sensing experiments. Here we propose an intuitive model to analyze these phenomena from the viewpoint of the nanoparticle-induced multiple scattering of the azimuthally propagating mode(APM). The model unveils explicit relations between these phenomena and the phase change and energy loss of the APM when scattered at the nanoparticle; the model also explains the observed polarization-dependent preservation of one resonance and the particle-dependent redshift or blueshift. The model indicates that the particle-induced coupling between the pair of unperturbed degenerate whispering gallery modes(WGMs) and the coupling between the WGMs and the free-space radiation modes, which are widely adopted in current theoretical formalisms, are realized via the reflection and scattering-induced free-space radiation of the APM, respectively, and additionally exhibits the contribution of cross coupling between the unperturbed WGMs and other different WGMs to forming the splittingresonant modes, especially for large particles.展开更多
The calcium fluoride(CaF_(2))whispering gallery mode crystalline resonator is an excellent platform for nonlinear optical applications because of the decreasing in threshold caused by ultrahigh quality(Q)factor.In thi...The calcium fluoride(CaF_(2))whispering gallery mode crystalline resonator is an excellent platform for nonlinear optical applications because of the decreasing in threshold caused by ultrahigh quality(Q)factor.In this paper,we achieved the observation of Raman lasing,first-order Raman comb,and second-order Raman lasing in a CaF_(2)disk resonator with a diameter of 4.96 mm and an ultrahigh-Q of 8.43×10^(8)at 1550-nm wavelength.We also observed thermal effects in CaF_(2)disk resonator,and the threshold of thermo-optical oscillation is approximately coincident with Raman lasing,since the intracavity power increases rapidly when the power reaches the threshold,and higher input pump power results in longer thermal drift and higher Raman emission power.With a further increase in pump power,the optical frequency combs range is from 1520 nm to 1650 nm,with a wavelength interval of 4×FSR.It is a promising candidate for optical communication,biological environment monitoring,spectral analysis,and microwave signal sources.展开更多
Lasing emissions with multiple and tunable modes are promising in coding field as a novel cryptographic primitive.With the advantages of simple fabrication,full-color and high-quality-factor whispering gallery mode la...Lasing emissions with multiple and tunable modes are promising in coding field as a novel cryptographic primitive.With the advantages of simple fabrication,full-color and high-quality-factor whispering gallery mode lasing inside a circular cross-section,polymer microfibers are attractive for photonic devices.However,polymer lasing microfibers for information encryption have never been reported.Herein,we propose a design of printable lasing microfiber encryption chip by in-situ tuning the effective refractive index of the microresonator arrays via a facile approach.Through inkjet printing high-refractive-index nanoparticles on the designated position of lasing microfiber arrays,the effective refractive index of the microcavities is regulated,and the ratio of wavenumber spacing between transverse electric and transverse magnetic mode to the free spectral range can be modulated,particularly with neglectable influence by the size factor.Thus,the programmable region selective encoding process can be conducted simply by a printing program within several minutes.Besides,the encoded microfiber arrays are encapsulated into polydimethylsiloxane to reduce the scattering loss and environmental interference,and a printable encryption chip is realized.This work is expected to provide a platform for the printable encrypted devices.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
We report the fabrication and characterization of germanium gallium antimony sulfide(Ge–Ga–Sb–S or 2 S2 G, doped with Tm^(3+)ions) microsphere lasers operating at ～1.9-μm spectral band. Compared to the chalcogeni...We report the fabrication and characterization of germanium gallium antimony sulfide(Ge–Ga–Sb–S or 2 S2 G, doped with Tm^(3+)ions) microsphere lasers operating at ～1.9-μm spectral band. Compared to the chalcogenide glasses that are used in previous microsphere lasers, this 2 S2 G glass has a lower transition temperature and a higher characteristic temperature. This implies that 2 S2 G microspheres can be fabricated at lower temperatures and the crystallization problem in the sphere-forming process can be alleviated. We show that hundreds of high-quality microspheres(quality factors higher than 105) of various diameters can be produced simultaneously via a droplet sphere-forming method. Microspheres are coupled with silica fiber tapers for optical characterizations. We demonstrate that Whispering Gallery mode(WGM)patterns in the 1.7–2.0 μm band can be conveniently obtained and that once the pump power exceeds a threshold, single-and multi-mode microsphere lasers can be generated. For a typical microsphere whose diameter is 258.64 μm, we demonstrate its laser threshold is 0.383 mW, the laser wavelength is 1907.38 nm, and the thermal sensitivity of the microsphere laser is29.56 pm/?C.展开更多
<div style="text-align:justify;"> The optical WGM resonator plays an important role in modern physics due to its ultra-high quality factor and small volume mode. In optics, SPPs modes can effectively c...<div style="text-align:justify;"> The optical WGM resonator plays an important role in modern physics due to its ultra-high quality factor and small volume mode. In optics, SPPs modes can effectively confine electromagnetic waves at the interface between metal and dielectric, providing extremely high sensitivity. New interesting WGM phenomena will emerge when the WGM is combined with the SPPs. In this paper, a cogwheel resonator based on spoof SPPs was designed, which can generate multi-order WGM modes. The transmission coefficients, dispersion relations and resonance modes of the WGM resonator were analyzed. The proposed resonator extends the WGM mode from optical band to microwave band, providing a new perspective for the applications of WGM mode at microwave band. </div>展开更多
Mode characteristics of metallically confined microcircular resonators are theoretically studied by solving eigenvalue equations for two-dimensional multilayer structures.The influences of conventional metals includin...Mode characteristics of metallically confined microcircular resonators are theoretically studied by solving eigenvalue equations for two-dimensional multilayer structures.The influences of conventional metals including Au,Ag,Cu,Al,and Ti,on the mode wavelengths and Q factors of whispering gallery modes(WGMs) are analyzed and compared.The results show silver has the best optical confinement among these metals,and aluminum presents similar behavior to Au.However,Ti,which is usually applied to enhance the adhesion of p-electrode to semiconductors,results in a great dissipation for confined modes.Furthermore,circular microlasers with Al as both p-electrode and optical confinement medium are fabricated,and continuous-wave operations are realized at room temperature for the microlasers with a radius of 15 μm.展开更多
An optical scrambler using a whispering-gallery-mode[WGM]micro-bottle cavity to scramble a complex optical signal to generate an uncorrelated output is proposed.We experimentally demonstrated this micro-cavity scrambl...An optical scrambler using a whispering-gallery-mode[WGM]micro-bottle cavity to scramble a complex optical signal to generate an uncorrelated output is proposed.We experimentally demonstrated this micro-cavity scrambler by using chaotic laser light as the incident signal and studied the influence of the coupling state.Experiments achieved full scrambling with a low cross correlation of 0.028 between the output and the input.Results indicate that the scrambling effect originates from the interference among numerous WGMs in the bottle cavity.It is believed that the micro-bottle cavity with an efficient scrambling function can become a promising candidate for encryption.展开更多
In-fber whispering gallery mode(WGM)microsphere resonators have received remarkable attention due to the superiorities of compact structure,high stability and self-alignment.As an in-fber structure,WGM microsphere res...In-fber whispering gallery mode(WGM)microsphere resonators have received remarkable attention due to the superiorities of compact structure,high stability and self-alignment.As an in-fber structure,WGM microsphere resonators have been demonstrated in various applications,such as sensors,flters and lasers,which have signifcant impacts on modern optics.Herein,we review recent progress of in-fber WGM microsphere resonators,which involve fbers of diverse structures and microspheres of diferent materials.First,a brief introduction is given to in-fber WGM microsphere resonators,from structures to applications.Then,we focus on recent progresses in this feld,including in-fber couplers based on conventional fbers,capillaries and micro-structure hollow fbers,and passive/active microspheres.Finally,future developments of the in-fber WGM microsphere resonators are envisioned.展开更多
The ringing phenomenon has been studied in optical whispering gallery mode(WGM)resonators and can be used to sense the ultrafast process in spectroscopy.Here we observe the ringing phenomenon in a magnomechanical syst...The ringing phenomenon has been studied in optical whispering gallery mode(WGM)resonators and can be used to sense the ultrafast process in spectroscopy.Here we observe the ringing phenomenon in a magnomechanical system for the first time,which is induced by the interference between the microwave photons converted from the damped phonons and the probing microwave photons.This interference eventually appears as a transparency window even along with the ringing phenomenon in the measured microwave reflection spectrum,which is influenced by the scanning speed and the input power.Then,the ringing spectroscopy is used to measure the coupling strength between the magnon and phonon modes,and outline the displacement profile of𝑆1,2,2 mechanical mode in a YIG microsphere,demonstrating the theoretical analysis.In addition,the ring-up spectroscopy is developed in our magnomechanical system,laying the foundation for fast sensing based on mechanical motion.展开更多
Zinc oxide(ZnO)optical microcavity modulated UV lasers have been attracting a wide range of research interests.As one of the most important materials in developing high quality microcavity and efficient UV evisible op...Zinc oxide(ZnO)optical microcavity modulated UV lasers have been attracting a wide range of research interests.As one of the most important materials in developing high quality microcavity and efficient UV evisible optoelectronic devices due to its wide band gap(3.37 eV)and large exciton binding energy(~60 meV).In this review,we summarized the latest development of ZnO optical cavity based microlasers,mainly including Fabry-Perot mode lasers and whispering gallery mode lasers.The synthesis and optical studies of ZnO optical microcavities with different morphologies were discussed in detail.Finally,we also consider that the research focus in the near future would include new nanotechnology and physical effects,such as nano/micro fabrication,surface plasmon enhancement,and quantum dot coupling,which may result in new and interesting physical phenomena.展开更多
Resonant light pressure effects can open new degrees of freedom in optical manipulation with microparticles,but they have been traditionally considered as relatively subtle effects.Using a simplified two-dimensional m...Resonant light pressure effects can open new degrees of freedom in optical manipulation with microparticles,but they have been traditionally considered as relatively subtle effects.Using a simplified two-dimensional model of surface electromagnetic waves evanescently coupled to whispering gallery modes(WGMs)in transparent circular cavities,we show that under resonant conditions the peaks of the optical forces can approach theoretical limits imposed by the momentum conservation law on totally absorbing particles.Experimentally,we proved the existence of strong peaks of the optical forces by studying the optical propulsion of dielectric microspheres along tapered microfibers.We observed giant optical propelling velocities,0.45 mm s21 for some of the 15-20 mm polystyrene microspheres in water for guided powers limited at,43 mW.Such velocities exceed previous observations by more than an order of magnitude,thereby providing evidence for the strongly enhanced resonant optical forces.We analyzed the statistical properties of the velocity distribution function measured for slightly disordered(,1%size variations)ensembles of microspheres with mean diameters varying from 3 to 20 mm.These results demonstrate a principal possibility of optical sorting of microspheres with the positions of WGM resonances overlapped at the wavelength of the laser source.They can be used as building blocks of the lossless coupled resonator optical waveguides and various integrated optoelectronics devices.展开更多
文摘During the last decades the whispering gallery mode based sensors have become a prominent solution for label-free sensing of various physical and chemical parameters.At the same time,the widespread utilization of the approach is hindered by the restricted applicability of the known configurations for ambient variations quantification outside the laboratory conditions and their low affordability,where necessity on the spectrally-resolved data collection is among the main limiting factors.In this paper we demonstrate the first realization of an affordable whispering gallery mode sensor powered by deep learning and multi-resonator imaging at a fixed frequency.It has been shown that the approach enables refractive index unit(RIU)prediction with an absolute error at 3×10^(-6) level for dynamic range of the RIU variations from 0 to 2×10^(-3) with temporal resolution of several milliseconds and instrument-driven detection limit of 3×10−5.High sensing accuracy together with instrumental affordability and production simplicity places the reported detector among the most cost-effective realizations of the whispering gallery mode approach.The proposed solution is expected to have a great impact on the shift of the whole sensing paradigm away from the model-based and to the flexible self-learning solutions.
基金National Science Foundation(NSF)(CBET1264750,CBET 1264997)Army Research Office(ARO)(W911NF-16-1-0339)
文摘Conventionally, metallic nanostructures are used for surface-enhanced Raman spectroscopy(SERS), but recently there has been increasing interest in the enhancement of Raman scattering from dielectric substrates due to their improved stability and biocompatibility compared with metallic substrates. Here, we report the observation of enhanced Raman scattering from rhodamine 6 G molecules coated on silica microspheres. We excite the whispering gallery modes(WGMs) supported in the microspheres with a tapered fiber coupler for efficient WGM excitation, and the Raman enhancement can be attributed to the WGM mechanism. Strong resonance enhancement in pump laser intensity and modified Raman emission from the Purcell effect in the microsphere resonator are observed from the experiment and compared with theoretical results. A total Raman enhancement factor of 1.4 × 10~4 is observed, with contribution mostly from the enhancement in pump laser intensity. Our results show that, with an efficient pumping scheme, dielectric microspheres are a viable alternative to metallic SERS substrates.
基金supported by the National Natural Science Foundation of China(No.61275050)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120121110034)the Fundamental Research Funds for the Central Universities of Xiamen University(Nos.2010121059 and 2011121048)
文摘We report the fabrication and optical characterization of spherical whispering gallery mode(WGM)resonators made from ultraviolet(UV)-curable adhesive.The fabricated microspheres have good sphericity and surface smoothness,and can directly adhere to the tip of half-tapered fibers for easy manipulation.WGMs are e?ciently excited in the microsphere using an evanescent field of the tapered silica optical fibers.Resonances with quality factors of 1.3×105are observed.The dependence of wavelength shifts of WGM resonances on the input light powers shows that the resonant wavelength of the proposed microsphere resonators can be tuned thermo-optically.
基金supported by the National Natural Science Foundation of China(Nos.U1304608 and 61774053)the Project of Henan Provincial Department of Science and Technology(No.182102410047)the Program of Henan Polytechnic University(No.B2014-020)。
文摘In this letter,a humidity sensor is demonstrated by applying a whispering gallery mode(WGM)from a microsphere resonator onto the ZnO nanorods coated glass surface.The diameter of the microsphere was 234μm and the glass surface was coated with ZnO nanorods using the hydrothermal method at growth duration of 12 h.A significant response to humidity level ranging from 35%RH to 85%RH has been observed with the sensitivity of 0.0142 nm/%RH.The proposed humidity sensor has successfully employed to enhance interaction between the whispering gallery mode evanescent and surrounds analyte with the assistance of ZnO nanorods coated glass.
文摘With the support by the National Natural Science Foundation of China,Chinese Academy of Sciences,and Ministry of Science and Technology of China,the research group led by Dr.Dong Chunhua(董春华)at the CAS Key Lab of Quantum Information,University of Science and Technology of China。
基金This work was also supported by the Ministry of Science and Higher Education of the Russian Federation(project no.14.W03.31.0008)in part by the Russian Science Foundation(project no.20-12-00389)+1 种基金in part by the Russian Foundation for Basic Research(projects no.20-02-00715,no.21-58-10005,no.21-57-10001).Z.B.Wang acknowledges European ERDF grants(CPE 81400 and SPARCII c81133)through WEFO,and Royal society grants(IEC\NSFC\181378 and IEC\R2\202178).
文摘We show that electric field on the plane surface of truncated sphere or cylinders(so called Janus particles)have sharp resonances versus the depth of removed segment of a sphere or cylinder.These resonances are related to the excited whispering gallery waves caused by truncation.It is a new mechanism of the field localization.Optimization of this effect for cylinders permits to reach a super resolution in the line thickness,which can be used for contact optical lithography.
基金Project supported by the National Key Research and Development Program of China (Grant No. 2020YFA0710100)the National Natural Science Foundation of China (Grant Nos. 92050102 and 11874311)the Fundamental Research Funds for the Central Universities (Grant Nos. 20720220033 and 20720200074)。
文摘Super-resolution imaging with superlens has been one of the fundamental research topics. Unfortunately, the resolution of superlens is inevitably restrained by material loss. To address the problem, we introduce the solid immersion mechanism into the slab superlens and the cylindrical superlens. The proposed solid immersion slab superlens(SISSL) and the solid immersion cylindrical superlens(SICSL) can improve the resolution by converting evanescent wave to propagating wave using high refractive index materials. From the perspective of applications, the cylindrical superlens with finite cross section and the ability of magnification or demagnification has more advantages than the slab superlens. Therefore,we focus on demonstrating analytically the super-resolution imaging of SICSL. Due to the impedance mismatching caused by solid immersion mechanism, the whispering gallery modes(WGMs) are excited between SICSL and the air interface.We clarify the excitation conditions of WGMs and analyze their influence on the imaging quality of SICSL. The SISSL and SICSL may pave a way to apply in lithography technique and real-time biomolecular imaging in future.
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National Key Basic Research Program of China(2013CB328701)National Natural Science Foundation of China(NSFC)(61322508,11504270)
文摘Optical whispering gallery microcavities with high-quality factors have shown great potential toward achieveing ultrahigh-sensitivity sensing up to a single molecule or nanoparticle, which raises a huge demand on a deep theoretical insight into the crucial phenomena such as the mode shift, mode splitting, and mode broadening in sensing experiments. Here we propose an intuitive model to analyze these phenomena from the viewpoint of the nanoparticle-induced multiple scattering of the azimuthally propagating mode(APM). The model unveils explicit relations between these phenomena and the phase change and energy loss of the APM when scattered at the nanoparticle; the model also explains the observed polarization-dependent preservation of one resonance and the particle-dependent redshift or blueshift. The model indicates that the particle-induced coupling between the pair of unperturbed degenerate whispering gallery modes(WGMs) and the coupling between the WGMs and the free-space radiation modes, which are widely adopted in current theoretical formalisms, are realized via the reflection and scattering-induced free-space radiation of the APM, respectively, and additionally exhibits the contribution of cross coupling between the unperturbed WGMs and other different WGMs to forming the splittingresonant modes, especially for large particles.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51727808,51922009,52005457,and 62004179)the Fund from the Key Laboratory of Quantum Sensing and Precision Measurement of Shanxi Province,China(Grant No.201905D121001)。
文摘The calcium fluoride(CaF_(2))whispering gallery mode crystalline resonator is an excellent platform for nonlinear optical applications because of the decreasing in threshold caused by ultrahigh quality(Q)factor.In this paper,we achieved the observation of Raman lasing,first-order Raman comb,and second-order Raman lasing in a CaF_(2)disk resonator with a diameter of 4.96 mm and an ultrahigh-Q of 8.43×10^(8)at 1550-nm wavelength.We also observed thermal effects in CaF_(2)disk resonator,and the threshold of thermo-optical oscillation is approximately coincident with Raman lasing,since the intracavity power increases rapidly when the power reaches the threshold,and higher input pump power results in longer thermal drift and higher Raman emission power.With a further increase in pump power,the optical frequency combs range is from 1520 nm to 1650 nm,with a wavelength interval of 4×FSR.It is a promising candidate for optical communication,biological environment monitoring,spectral analysis,and microwave signal sources.
基金The authors would like to acknowledge the National Natural Science Foundation of China(NSFC)(Nos.52203252 and 61822501)the Beijing Natural Science Foundation(No.Z180015)for financial support.
文摘Lasing emissions with multiple and tunable modes are promising in coding field as a novel cryptographic primitive.With the advantages of simple fabrication,full-color and high-quality-factor whispering gallery mode lasing inside a circular cross-section,polymer microfibers are attractive for photonic devices.However,polymer lasing microfibers for information encryption have never been reported.Herein,we propose a design of printable lasing microfiber encryption chip by in-situ tuning the effective refractive index of the microresonator arrays via a facile approach.Through inkjet printing high-refractive-index nanoparticles on the designated position of lasing microfiber arrays,the effective refractive index of the microcavities is regulated,and the ratio of wavenumber spacing between transverse electric and transverse magnetic mode to the free spectral range can be modulated,particularly with neglectable influence by the size factor.Thus,the programmable region selective encoding process can be conducted simply by a printing program within several minutes.Besides,the encoded microfiber arrays are encapsulated into polydimethylsiloxane to reduce the scattering loss and environmental interference,and a printable encryption chip is realized.This work is expected to provide a platform for the printable encrypted devices.
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.
基金Project supported by the National Natural Science Foundation of China(Grant No.61605094)the Key Program of National Natural Science Foundation of China(Grant No.61435009)+1 种基金the Natural Science Foundation of Zhejiang Province,China(Grant No.LQ15F050002)K.C.Wong Magna Fund in Ningbo University,China
文摘We report the fabrication and characterization of germanium gallium antimony sulfide(Ge–Ga–Sb–S or 2 S2 G, doped with Tm^(3+)ions) microsphere lasers operating at ～1.9-μm spectral band. Compared to the chalcogenide glasses that are used in previous microsphere lasers, this 2 S2 G glass has a lower transition temperature and a higher characteristic temperature. This implies that 2 S2 G microspheres can be fabricated at lower temperatures and the crystallization problem in the sphere-forming process can be alleviated. We show that hundreds of high-quality microspheres(quality factors higher than 105) of various diameters can be produced simultaneously via a droplet sphere-forming method. Microspheres are coupled with silica fiber tapers for optical characterizations. We demonstrate that Whispering Gallery mode(WGM)patterns in the 1.7–2.0 μm band can be conveniently obtained and that once the pump power exceeds a threshold, single-and multi-mode microsphere lasers can be generated. For a typical microsphere whose diameter is 258.64 μm, we demonstrate its laser threshold is 0.383 mW, the laser wavelength is 1907.38 nm, and the thermal sensitivity of the microsphere laser is29.56 pm/?C.
文摘<div style="text-align:justify;"> The optical WGM resonator plays an important role in modern physics due to its ultra-high quality factor and small volume mode. In optics, SPPs modes can effectively confine electromagnetic waves at the interface between metal and dielectric, providing extremely high sensitivity. New interesting WGM phenomena will emerge when the WGM is combined with the SPPs. In this paper, a cogwheel resonator based on spoof SPPs was designed, which can generate multi-order WGM modes. The transmission coefficients, dispersion relations and resonance modes of the WGM resonator were analyzed. The proposed resonator extends the WGM mode from optical band to microwave band, providing a new perspective for the applications of WGM mode at microwave band. </div>
基金Project supported by the National Natural Science Foundation of China(Nos.61376048,61106048)
文摘Mode characteristics of metallically confined microcircular resonators are theoretically studied by solving eigenvalue equations for two-dimensional multilayer structures.The influences of conventional metals including Au,Ag,Cu,Al,and Ti,on the mode wavelengths and Q factors of whispering gallery modes(WGMs) are analyzed and compared.The results show silver has the best optical confinement among these metals,and aluminum presents similar behavior to Au.However,Ti,which is usually applied to enhance the adhesion of p-electrode to semiconductors,results in a great dissipation for confined modes.Furthermore,circular microlasers with Al as both p-electrode and optical confinement medium are fabricated,and continuous-wave operations are realized at room temperature for the microlasers with a radius of 15 μm.
基金supported by the National Key Research and Development Program of China(No.2019YFB1803500)the National Natural Science Foundation of China(NSFC)(Nos.62105233,62035009,and 61731014)+4 种基金the Natural Science Foundation of Shanxi Province(Nos.20210302124536 and 20210302123183)the Major Key Project of PCL(No.PCL2021A14)the Shanxi“1331 Project”Key Innovative Teamthe Program for Guangdong Introducing Innovative and Entrepreneurial Teamsthe International Cooperation of Key R&D Program of Shanxi Province(No.201903D421012)。
文摘An optical scrambler using a whispering-gallery-mode[WGM]micro-bottle cavity to scramble a complex optical signal to generate an uncorrelated output is proposed.We experimentally demonstrated this micro-cavity scrambler by using chaotic laser light as the incident signal and studied the influence of the coupling state.Experiments achieved full scrambling with a low cross correlation of 0.028 between the output and the input.Results indicate that the scrambling effect originates from the interference among numerous WGMs in the bottle cavity.It is believed that the micro-bottle cavity with an efficient scrambling function can become a promising candidate for encryption.
基金supported by the National Key Research and Development Program of China(No.2022YFF0708400)the National Natural Science Foundation of China(NSFC)(Grant Nos.62022053,61875116,and 62205192)+3 种基金the 111 Project(D20031)the Advanced Optical Waveguide Intelligent Manufacturing and Testing Professional Technical Service Platform of Shanghai(19 DZ2294000)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2021WNLOKF002)the Science and Technology Commission of Shanghai Municipality Project Grant(22010500100,22ZR1424800).
文摘In-fber whispering gallery mode(WGM)microsphere resonators have received remarkable attention due to the superiorities of compact structure,high stability and self-alignment.As an in-fber structure,WGM microsphere resonators have been demonstrated in various applications,such as sensors,flters and lasers,which have signifcant impacts on modern optics.Herein,we review recent progress of in-fber WGM microsphere resonators,which involve fbers of diverse structures and microspheres of diferent materials.First,a brief introduction is given to in-fber WGM microsphere resonators,from structures to applications.Then,we focus on recent progresses in this feld,including in-fber couplers based on conventional fbers,capillaries and micro-structure hollow fbers,and passive/active microspheres.Finally,future developments of the in-fber WGM microsphere resonators are envisioned.
基金supported by the National Key Research and Development Program of China(2020YFB2205801)Innovation program for Quantum Science and Technology(2021ZD0303203)+2 种基金National Natural Science Foundation of China(11934012,11874342 and 92050109)USTC Research Funds of the Double First-Class Initiative(YD2470002002)the Fundamental Research Funds for the Central Universities.
文摘The ringing phenomenon has been studied in optical whispering gallery mode(WGM)resonators and can be used to sense the ultrafast process in spectroscopy.Here we observe the ringing phenomenon in a magnomechanical system for the first time,which is induced by the interference between the microwave photons converted from the damped phonons and the probing microwave photons.This interference eventually appears as a transparency window even along with the ringing phenomenon in the measured microwave reflection spectrum,which is influenced by the scanning speed and the input power.Then,the ringing spectroscopy is used to measure the coupling strength between the magnon and phonon modes,and outline the displacement profile of𝑆1,2,2 mechanical mode in a YIG microsphere,demonstrating the theoretical analysis.In addition,the ring-up spectroscopy is developed in our magnomechanical system,laying the foundation for fast sensing based on mechanical motion.
基金This work was supported financially by the NSFC(61378074,61475173,61675219)Youth Innovation Promotion Association CAS.
文摘Zinc oxide(ZnO)optical microcavity modulated UV lasers have been attracting a wide range of research interests.As one of the most important materials in developing high quality microcavity and efficient UV evisible optoelectronic devices due to its wide band gap(3.37 eV)and large exciton binding energy(~60 meV).In this review,we summarized the latest development of ZnO optical cavity based microlasers,mainly including Fabry-Perot mode lasers and whispering gallery mode lasers.The synthesis and optical studies of ZnO optical microcavities with different morphologies were discussed in detail.Finally,we also consider that the research focus in the near future would include new nanotechnology and physical effects,such as nano/micro fabrication,surface plasmon enhancement,and quantum dot coupling,which may result in new and interesting physical phenomena.
基金The authors thank Ilya Vitebskiy,Vassilios Kovanis and Nicholaos Limberopoulos for stimulating discussions.YL,OVS and VNA gratefully acknowledge support for our work from the US Army Research Office(ARO)under grant W911NF-09-1-0450 and DURIP W911NF-11-1-0406 and W911NF-12-1-0538(John T Prater)from the National Science Foundation(NSF)under grant ECCS-0824067+1 种基金AVM gratefully acknowledges a partial support from the Ministry of Education and Science of the Russian Federation through agreement no.14.B37.21.0892.DCER gratefully acknowledge a partial support from the EU FP7 program through FAST-DOT project(contract no.224338).
文摘Resonant light pressure effects can open new degrees of freedom in optical manipulation with microparticles,but they have been traditionally considered as relatively subtle effects.Using a simplified two-dimensional model of surface electromagnetic waves evanescently coupled to whispering gallery modes(WGMs)in transparent circular cavities,we show that under resonant conditions the peaks of the optical forces can approach theoretical limits imposed by the momentum conservation law on totally absorbing particles.Experimentally,we proved the existence of strong peaks of the optical forces by studying the optical propulsion of dielectric microspheres along tapered microfibers.We observed giant optical propelling velocities,0.45 mm s21 for some of the 15-20 mm polystyrene microspheres in water for guided powers limited at,43 mW.Such velocities exceed previous observations by more than an order of magnitude,thereby providing evidence for the strongly enhanced resonant optical forces.We analyzed the statistical properties of the velocity distribution function measured for slightly disordered(,1%size variations)ensembles of microspheres with mean diameters varying from 3 to 20 mm.These results demonstrate a principal possibility of optical sorting of microspheres with the positions of WGM resonances overlapped at the wavelength of the laser source.They can be used as building blocks of the lossless coupled resonator optical waveguides and various integrated optoelectronics devices.
