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- 实验方案
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Up-Conversion Luminescence and C-Band Laser in Er <sup>3+</sup> -Doped Fluorozirconate Glass Microsphere Resonator
摘要： Up-conversion luminescence and C-band microsphere laser output is reported for an Er3+-doped ZrF4-BaF2-YF3-AlF3 (ZBYA) fluorozirconate glass microsphere. The microsphere was fabricated by heating a ZBYA glass filament using a CO2 laser beam. The fabrication process accurately and repeatably produces microspheres of 68 μm diameter. The input and output laser light was coupled to the microsphere using a tapered optical fiber. The coupling position between the tapered fiber and microsphere was adjusted using a sophisticated three-dimensional translation stage. The up-conversion luminescence emission, single-mode and multi-mode laser at C-band (1530 to 1565 nm) were observed when pumped using a 980 nm laser.
关键词： fluorozirconate glass,microsphere resonator,Up-conversion luminescence,C-band laser
更新于2025-09-16 10:30:52
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An electrically controlled light-scattering device based on liquid crystal/polymer microsphere composites
摘要： There is a widely applied prospect of electrical controlled liquid crystal (LC) light-scattering device. Numerous electrical controlled LC light-scattering technologies have been studied, but each technology has its own shortcomings, such as high driving voltage, high hysteresis, complex electrode structure, and serious heating. In this work, the composite of LC and polymer microspheres are used to fabricate light-scattering devices. This device is operated by the vertical electric field and does not require complex preparation process. LC/polymer microsphere composite has the advantages of low driving voltage and zero hysteresis. The role of microspheres in the composites is to change the size and density of a refractive-index-mismatched micro-domain. The effects of the ratio, particle size, and refractive index of microspheres on the optical characteristics of a composite are studied. The normal directional light transmittance at the transparent state and light-scattering state decreases with an increasing weight ratio of microspheres. The particle size of microspheres has negligible influence on the electro-optical properties of composites when the weight ratio of microspheres is small. The LCs doped with Polymethylsilsesquioxane (PMSQ) microspheres or polymethyl methacrylate (PMMA) microspheres are compared, and the mismatched refractive index and density of micro-domain show the influence on the electro-optical properties of the composites.
关键词： zero hysteresis,electro-optical properties,liquid crystal/polymer microsphere composites,Liquid crystal light-scattering device
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Effective Coupling of a Plasmonic Nanorod to a Microsphere Resonator
摘要： Coupled photonic-plasmonic systems have already proven successful as ultra-sensitive sensors with the potential of single virus detection. Such systems are e.g. composed of a plasmonic nanoparticle in vicinity of an optical resonator usually in the form of a microsphere, a mirroring or a microdisk. These systems are proven highly sensitive due to their large quality factor and are thus utilized as bio, pressure, gas or temperature sensors. When a plasmonic nanoparticle is positioned near such resonator, coupling of the plasmonic and photonic modes can result in an ultra-sensitive biosensor, since nanoparticle presence enhance ambient refractive index (RI) variation sensitivity. In this paper, photonic-plasmonic coupling of a gold nanorod in close vicinity of a silica microsphere is simulated in order to investigate various types of coupling settings in such systems. The presence of the nanorod results in a frequency shift as well as in a reduction of the quality factor, which are both highly dependent on nanorod properties such as size, distance between the particle and the sphere as well as the nanorod orientation relative to the sphere surface. A single gold nanorod is positioned in 50nm distance to a 15.5μm silica microsphere which supports a whispering gallery mode at 1550nm and both resonance frequency and quality factor are computed using the simulation platform COMSOL Multiphysics. The nanorod orientation is altered starting from the tangential direction with respect to the sphere surface (0o) to the perpendicular direction (90o). In the Fig 1a) the quality factor together with the damping constant is shown as a function of the nanorod orientation for at an operating wavelength of 1550nm. The 90o direction results in higher quality factor as well as a better mode stability although the frequency shift associated to a 90o turn is only about 10GHz. In Fig 1b) the frequency shift and quality factor for the perpendicular nanorod versus ambient medium RI is plotted, which confirms the ultra-sensitivity of the designed optical resonator up to a 10-3 RI shift. The electric field distribution outside and inside of the nanorod is illustrated in Fig. 1c) for the three directions 90o, 45o and 0o where the perpendicular nanorod shows the weakest interaction with the excited whispering gallery mode and thus yields the largest quality factor.
关键词： silica microsphere,photonic-plasmonic coupling,gold nanorod,COMSOL Multiphysics,whispering gallery mode
更新于2025-09-12 10:27:22
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Label-Free Super-Resolution Imaging of Transparent Dielectric Objects Assembled on Silver Film by a Microsphere-Assisted Microscope
摘要： In optical microscopy, label-free imaging transparent dielectric objects with sub-wavelength features is still a challenge. We propose a method to super-resolution image a label-free transparent periodic object using the microsphere-assisted bright-field microscope. A two-dimensional array of label-free hexagonally close-packed polystyrene (PS) nanoparticles with a diameter of 250 nm assembled on a silver film coated glass slide can be discerned by coupling a classical optical microscope with a 30-μm-diameter BaTiO3 glass (BTG) microsphere. However, when the PS nanoparticle array with the same diameter is assembled on either a glass slide or a high-reflectance dielectric multilayer coated glass slide, it cannot be resolved. We propose that period plasmonic near-field illumination is generated due to the excitation of surface plasmon polarition modes on periodically structured interfaces. More high-frequency information of the object is coupled into the BTG microsphere lens, resulting in the improvement of imaging resolution.
关键词： transparent dielectric objects,surface plasmon polarition modes,microsphere-assisted microscope,label-free imaging,super-resolution
更新于2025-09-12 10:27:22
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[IEEE 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII) - Berlin, Germany (2019.6.23-2019.6.27)] 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII) - Functional Plasmonic Fiber-Optic Based Sensors Using Low-Cost Microsphere Photolithography
摘要： This paper presents a technique for the low-cost fabrication of plasmonic fiber-optic based refractive-index sensors. The Microsphere Photolithography (MPL) technique was used to pattern nanoholes in a thin aluminum to create Extraordinary Optical Transmission (EOT) based sensors on the cleaved tip of SMF-28 optical fibers. This technique uses self-assembled microspheres as an optical element and facilitates very low-cost patterning of the plasmonic probes. As the refractive index of the media changes, the reflected spectrum of optical fiber changes. The fabricated sensors were immersed in water with different concentrations of glucose, and the lowest detection limit was found to be 33 mg/mL.
关键词： Fiber,Glucose detection,Microsphere photolithography,Plasmonic sensor
更新于2025-09-12 10:27:22
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Research on Fabrication and Sensing Properties of Fiber-Coupled Whispering Gallery Mode Microsphere Resonator
摘要： In this paper, a fiber-coupled whispering gallery mode (WGM) microsphere resonator was fabricated with using a simple package scheme. The resonant properties of the WGM resonator are analyzed and their responses to bulk refractive index and temperature are theoretically and experimentally investigated. Experiment results show that the bulk refractive index sensitivity is about 20.49 nm/RIU with detection limit of 4.3×10-4 RIU and very low temperature sensitivity of 7.38 pm/℃. Moreover, the WGM microsphere resonator is firstly used for acoustic intensity level sensing, and the sensitivity is about -1.9 pm/dB, which can enlarge the application field of the WGM sensor and can be used for noise monitoring to enhance environmental protection.
关键词： Whispering gallery mode,Temperature sensor,Microsphere resonator,Refractive index sensor,Acoustic intensity level sensor
更新于2025-09-12 10:27:22
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Crystal phase control synthesis of metallic 1T-WS2 nanosheets incorporating single walled carbon nanotubes to construct superior microwave absorber
摘要： Two-dimensional transition metal dichalcogenides (TMDs) have attracted tremendous attentions due to their unique properties, and the development of phase control technique brings out new opportunities in emerging application fields. In this work, tungsten disulfide (WS2) nanosheets containing 1T phase predominately were incorporated with single walled carbon nanotubes (SWCNTs) through a facial hydrothermal method. Two-dimensional flexible and ultrathin WS2 nanosheets were in-situ grown on one-dimensional SWCNTs bundles, further forming typical urchin-like microsphere with diameters distributing in the range of 2~3 μm uniformly. Accordingly, dielectric loss could be significantly enhanced due to the strong interface coupling effect between WS2 nanosheets and SWCNTs bundles, which induced considerable electrical conductivity and abundant capacitor-like structures. Consequently, the minimum reflection loss (RL) could reach up to -66 dB at 8.3 GHz with a matching thickness of 2.2 mm. Furthermore, RL values lower than -10 dB could be attained in the range of 3.0~18.0 GHz with integrated thicknesses from 5.0 to 1.0 mm. Prospectively, our present work may provide new opportunity to design TMDs based composites by means of crystal phase control technique as lightweight and high-performance microwave absorbers.
关键词： urchin-like microsphere,high-efficient microwave absorber,crystal phase control,1T-WS2/SWCNTs hybrid composites
更新于2025-09-12 10:27:22
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Micro-Cantilever Displacement Detection Based in Optical Fiber Tip
摘要： This work demonstrates the potential of combining a microsphere with a tip for the functionality of the contact sensor. This sensor consists of a tip aligned with the fiber core and a microsphere, which appears during tip formation. This new structure was produced using the electric arc machine. The sensor operation consists of the variation of the tip curvature, which causes a variation of the optical paths and, consequently, a change in the output signal. The study of this micro-cantilever consisted of an exploration of the contact mode. In addition, the sensor was characterized by temperature, which shows very low sensitivity and vibration. This last characterization was performed with two configurations parallel and perpendicular to the oscillating surface. The perpendicular case showed higher sensitivity and has an operating band of 0 Hz to 20 kHz. In this configuration, for frequencies up to 2 Hz, the intensity varies linearly with the frequencies and with a sensitivity of 0.032 ± 0.001 (Hz?1). For the parallel case, the operating band was from 1.5 kHz to 7 kHz.
关键词： detection,physic,cantilever,microsphere,optical fiber structure,optic,sensor,vibration,tip
更新于2025-09-12 10:27:22
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Computer Aided Patterning Design for Self-Assembled Microsphere Lithography (SA-MSL)
摘要： In this paper, we use a finite difference time domain solver to simulate the near field optical properties of self-assembled microsphere arrays when exposed to an incoherent light source. Such arrays are typically used for microsphere lithography where each sphere acts as a ball lens, focusing ultraviolet light into an underlying photoresist layer. it is well known that arrays of circular features can be patterned using this technique. However, here, our simulations show that additional nanometer scale features can be introduced to the pattern by optimising the sphere dimensions and exposure conditions. these features are shown to arise from the contact points between the microspheres which produce paths for light leakage. for hexagonally close packed arrays, the six points of contact lead to star shapes in the photoresist. These star shapes have subfeature sizes comparable to the current achievable resolution of low-cost fabrication techniques.
关键词： finite difference time domain solver,microsphere arrays,SA-MSL,photoresist,Self-assembled microsphere lithography
更新于2025-09-11 14:15:04
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Multi-height phase recovery combined with Fast Iterative Shrinkage-Thresholding Algorithm to handle phase microspheres from complex diffracted field in inline holography
摘要： We describe in this work an approach that individually combines constant initialization, free-space backpropagation, transport of intensity equation (TIE) and multi-height phase recovery with Fast Iterative Shrinkage-Thresholding Algorithm (FISTA) to predict reconstruction of the phase microspheres from diffracted field measurements. We incorporate appropriate initialization and regularization to reconstruct unknown phase microspheres (transparent objects).
关键词： phase recovery,diffraction,object bounds,phase microsphere,computational imaging,Inline holography
更新于2025-09-11 14:15:04