Metasurfaces, which consist of resonant metamaterial elements in the form of two‐dimensional thin planar structures, retain great capabilities in manipulating electromagnetic wave and potential applications in modifying interaction with fluorescent molecules. The metasurfaces with magnetic responses are favorable to weakening fluorescence quenching while less investigated in controlling fluorescence. In this paper, we demonstrate control over fluorescence emission by engineering the magnetic and electric modes in plasmonic metasurfaces consisting of 45‐nm‐thick gold split‐ring‐resonators (SRRs). The fluorescence emission exhibits an enhancement factor of ∼18 and is predominantly x‐polarized with assistance of the magnetic mode excited by oblique incidence with an x‐polarized electric field. The magnetic and electric modes excited by oblique incidence with a y‐polarized electric field contribute to the rotation of emission polarization with respect to the incident polarization. The results demonstrate manipulating the interaction of fluorescent emitters with different resonant modes of the SRR‐based metasurface at the nanoscale by the polarization of incident light, providing potential applications of metasurfaces in a wide variety of areas, including optical nanosources, fluorescence spectroscopy and compact biosensors.
The frequency distribution of the fluorescent light induced by monochromatic dye laser radiation was investigated. To exclude the influence of the Doppler width a strongly collimated atomic beam was used. The spectrum was measured by means of a piezoelectrically tunable spherical Fabry Perot. The interaction region between the laser light and the atomic beam was placed into the center of the interferometer. Thus the observed fluorescence spectrum was considerably more intense than in the case where the interferometer is used separately from the beam. The fluorescence spectrum was observed for different directions of polarization of the incident laser beam. In the case of weak excitation the spectrum consists of a sharp component essentially due to elastically scattered light. At high intensities a structure of three components is observed which is in agreement with theoretical predictions when circularly polarized light is used for excitation. 相似文献
The frequency distribution of the fluorescent light induced by monochromatic dye laser radiation was investigated. To exclude the influence of the Doppler width a strongly collimated atomic beam was used. The spectrum was measured by means of a piezoelectrically tunable spherical Fabry Perot. The interaction region between the laser light and the atomic beam was placed into the center of the interferometer. Thus the observed fluorescence spectrum was considerably more intense than in the case where the interferometer is used separately from the beam. The fluorescence spectrum was observed for different directions of polarization of the incident laser beam. In the case of weak excitation the spectrum consists of a sharp component essentially due to elastically scattered light. At high intensities a structure of three components is observed which is in agreement with theoretical predictions when circularly polarized light is used for excitation. 相似文献
The fluorescence polarization method, recently developed for the evaluation of the preferential orientation of fluorescent dyes adsorbed in layered materials [F. López Arbeloa, V. Martínez Martínez, J. Photochem. Photobiol. A: Chem. 181 (2006) 44], is readapted to improve its application. Fluorescence polarization was previously obtained by recording the emission intensity for two orthogonal orientations of the emission polarizer (i.e., the horizontal and vertical polarized light) after excitation with vertical or horizontal polarized light. In the method proposed in this work, samples are excited with unpolarized light, reducing the polarization effect of the excitation light scattering at those emission wavelengths close to the excitation wavelength. Moreover, the present method decreases the effect of the orientation of other non-fluorescent species present in the system, which are active in the excitation process. Consequently, the new method is more simple, precise and sensitive. It is applied to evaluate the orientation of rhodamine 6G dye adsorbed in ordered laponite clay films with low and moderated dye loadings. 相似文献
The fluorescence behavior of a chiral polybinaphthyl excited with 100 fs 800 nm laser pulses was investigated in tetrahydrofuran solution. The peak fluorescence intensity versus the input irradiance was measured to meet a square dependence, giving evidence for two-photon excited fluorescence (TPF). The variations of the TPF intensity were found to be strongly modulated by the different polarized incident lights and tightly depend on the linearly polarized component of the incident light. Furthermore, combining with the characteristics of chiral molecules, the two-photon polarization ratio was studied to reveal the symmetry of the involved excited states. 相似文献
We have optimized the settings of evanescent wave imaging for the visualization of a protein adsorption layer.The enhancement of the evanescent wave at the interface brought by the incident angle,the polarized state of light beam as well as a gold layer is considered.In order to improve the image contrast of a protein monolayer in experiments,we have optimized three factors- the incident angle,the polarization of light beam,and the thickness of an introduced thin gold layer with a theoretical simulation. 相似文献
Whispering-gallery modes (WGMs) on Nd3+-doped glass microspheres with a radius of ~15?μm were measured in a modified confocal microscope, where a dual spatial resolution in both excitation and detection zones was possible. As an alternative to the standard excitation mechanism by an evanescent wave, we used an efficient pumping/detecting scheme, focusing a laser in the microsphere and exciting the Nd3+ ions, whose fluorescent emission produces the WGMs. We have also measured the generated WGMs by changing the detection zone, where higher amplitude resonances were found when exciting in the center and detecting at the edge of the microsphere. 相似文献
We analyze, via an off-axis incident model and three-dimensional particle-in-cell simulations, the influence of beam pointing fluctuations (BPFs) on the propagation properties of relativistic laser pulses in micro-tubes. It is observed that the in-tube laser intensity can be further amplified in the BPFs-induced off-axis incident case. But the intensification factor exhibits strong polarization-dependence. When the laser pulse is linearly polarized in the off-axis incident plane (p-polarization), more electrons may be dragged out from about a half of the tube inner surface in each across section than in the on-axis incident case, enhancing the effects of relativistic nonlinearity and channel focusing. The area for generating more electrons is reduced by one half in the s-polarization case, resulting in less efficient light intensification. The BPFs-induced off-axis incident also leads to pulse shortening. Moreover, light confinement in the tube core is evident and the laser pulse tends to be coaxial with the tube. 相似文献