Metal–Dielectric Waveguides for High Efficiency Fluorescence Imaging

Abstract

We demonstrate that Metal–Dielectric Waveguide structures (MDWs) with high efficiency of fluorescence coupling can be suitable as substrates for fluorescence imaging. This hybrid MDWs consists of a continuous metal film and a dielectric top layer. The optical modes sustaining inside this structure can be excited with a high numerical aperture (N.A) objective, and then focused into a virtual optical probe with high intensity, leading to efficient excitation of fluorophores deposited on top of the MDWs. The emitted fluorophores couple with the optical modes thus enabling the directional emission, which is verified by the back focal plane (BFP) imaging. These unique properties of MDWs have been adopted in a scanning laser confocal optical microscopy, and show the merit of high efficiency fluorescence imaging. MDWs can be easily fabricated by vapor deposition and/or spin coating, the silica surface of the MDWs is suitable for biomolecule tethering, and will offer new opportunities for cell biology and biophysics research.

Polarization‐ and Angle‐Dependent Plasmonic Synchronous Fluorescence Spectroscopy to Probe Molecular Vibrational Couplings on an Aluminum Nano‐Film

“…Compared with the failure of free space emission measurement to probe the polarization effects (inset of Figure 3a), the SPCE appearing as a cone of emission around the normal axis of the prism made a facile configuration for polarization determination through symmetrically and simultaneously setting in the emission paths (Figure 3a). [28] From the SPCE angle distribution of 300 nm AN at the emission wavelength of 426 nm in Figure S5a (Supporting Information), three SPCE angles with alternating p-and s-polarization could be observed due to the waveguide effect, which is consistent with the theoretical results (Figures S5b and S6, Supporting Information). [29] focusing on the transitions from the lowest excited singlet state of AN) as functions of energy difference and detection angle, the three-dimensional plotting maps were respectively constructed for p-polarization and s-polarization detection channels.…”

Metal-dielectric waveguide structure supporting an evanescent wave with long propagation distance in an aqueous environment

“…In this letter, we studied a metal-dielectric waveguide (MDW) structure that potentially addresses the aforementioned issues [28][29][30]. The MDW structure supports a waveguide mode within the dielectric layer, yielding an evanescent wave that propagates at the dielectric/environment interface with much lower ohmic loss.…”

Evanescent waves modulate energy efficiency of photocatalysis within TiO2 coated optical fibers illuminated using LEDs

“… where λ is the wavelength of light, n q and n e are the refractive index of quartz and external medium, respectively, E i is the radiant energy of incident light, and z n is the normalized distance between the fiber surface and TiO 2 nanoparticles at a TIR spot, which is equal to the average distance from the center of an evanescent field to the closest surrounding TiO 2 nanoparticles within the evanescent field ( δ i ), as shown in Fig. 3b 32 , 33 . In our study, the LED lamp source was fixed at one end of a quartz optical fiber, so θ remained the same and was always between 0.376π and 0.495π (calculation shown in Supplementary Note 5A ).…”