Surface Plasmon Emission Light Research Articles

Nano-Structured Organic Devises and Biosensors Utilizing Evanescent Waves and Surface Plasmon Resonance

In this review, we introduce a variety of surface sensitive techniques for the study of organic thin films, and applications to organic devices. These studies include surface plasmon emission light, organic thin film transistors, combination of quartz crystal microbalance and optical waveguide spectroscopy, evaluation of alignment of liquid crystal molecules at surfaces, and biosensor applications.

Electrochemical surface plasmon excitation and emission light properties in poly(3-hexylthiophene) thin films

The attenuated total reflection (ATR) and emission light properties utilizing surface plasmon (SP) excitations were measured for the electrochemical change of poly(3-hexylthiophene-2,5diyl) (P3HT) thin films in-situ. The SP emission light could detect the SP excited by molecular luminescence of P3HT. The ATR and SP emission light properties were observed for the doped–dedoped states of P3HT thin film. The ATR and SP emission light properties were remarkably changed with the electrochemical doping and dedoping. The SP emission light also decreased by decrease of the molecular luminescence of P3HT by doping. For the dedoped-state P3HT thin film, SP emission light also increased by increase of the molecular luminescence. The SP emission light excited by molecular luminescence can be controlled by the control of doping–dedoping state.

Surface Plasmon Excitation and Emission Light Property for Otto/Kretschmann Configuration with MEH-PPV Film

Attenuated total reflection (ATR) property utilizing surface plasmon (SP) excitation was investigated for BK-7 prism/MgF 2 /Ag film/fluorescent organic dye film structure. In the structure, it is expected that SPs are excited at MgF 2 /Ag and Ag/dye film interfaces by Otto and Kretschmann configurations, respectively. In the experimental ATR curve, reflection dips for the SP excitations at the interfaces could be detected. Furthermore, SP emission lights were observed by irradiation of Ar ion laser beam from the dye film side. The SP emission light curve with two peaks was observed and it was also considered that the peaks corresponded to the SP excitation of Otto and Kretschmann configurations. The SP emission light spectra indicated the excited fluorescent dyes induced the SP emission lights. Intense emission light of Otto configuration was observed in this sample.

Adsorption and Surface Plasmon Emission Light of Polystyrene Spheres with Fluorescent Dye on Ag Thin Film

In this study, attenuated total reflection (ATR) utilizing surface plasmon (SP) excitation and SP emission lights were observed for the adsorption of polystyrene (PS) spheres and a water-soluble polymer. The PS spheres contained fluorescent dyes and exhibited red fluorescence. The ATR properties indicated film deposition with increasing number of adsorption cycles. The SP emission light induced by the fluorescent dye in the spheres was also measured, and an increase in the peak intensity, as well as an angle shift, was observed. Furthermore, the SP emission light spectra were investigated at various emission angles. The dispersion relation obtained from the SP emission light almost corresponded to that obtained from the ATR curves.

Humidity Adsorption and Surface Plasmon Excitation of Poly(vinyl alcohol) Films with Fluorescent Microspheres

In this study, thin films of poly(vinyl alcohol) (PVA) mixed with 100 nm polystyrene (PS) microspheres were prepared, and changes in attenuated total reflection (ATR) utilizing surface plasmon (SP) excitation due to the adsorption of humidity were investigated. The PS microspheres contained luminescent dyes, and SP emission light due to these dyes was observed. The sample configuration was prism/Ag film (50 nm)/PVA film with sphere. ATR dip and SP emission peak angles shifted with the adsorption and desorption of humidity, and SP emission light intensity changed markedly. Furthermore, kinetic curves were plotted and humidity adsorption responses were repeatedly observed. Finally, the dispersion relations of SPs were obtained from ATR and SP emission light properties.

Humidity Sensing Using Surface Plasmon Excitation in Fluorescent Microsphere Films

In this study, thin films of 100-nm. polystyrene (PS) microspheres mixed with polyvinyl alcohol (PVA) were prepared, and changes in the attenuated total reflection (ATR) using surface plasmon (SP) excitation due to humidity adsorption were investigated. The PS microspheres contained luminescent dyes, and SP emission light due to these dyes was also observed. The sample configuration was prism /Ag film (50 nm) / sphere film structure. The ATR dip and SP emission peak angles shifted in line with the adsorption and desorption of humidity. Furthermore, the intensity of the SP emission light changed, and this was considered to be a result of the PVA swelling due to humidity adsorption. The humidity response of the ATR and SP emission light was repeatedly observed. The adsorbed mass was also monitored using a quartz crystal microbalance.

Surface Plasmon Emission Light Property due to Molecular Luminescence and Molecular Interaction

Surface plasmon (SP) emission light was observed for a merocyanine (MC) Langmuir-Blodgett (LB) film and an MC/crystal violet (CV) hetero-LB film in the ATR Kretschmann configuration. Intense photoluminescence of CV and quenching of MC were observed due to an energy transfer from MC to CV in the hetero-LB film. SP emission light due to CV was also observed for the MC/CV hetero-LB film. Furthermore, the emission light properties of the MC/CV hetero-LB film did not depend on the polarization direction of excitation light and were considered to be a result of the molecular shape of CV.

Conversion between Three- and Two-Dimensional Optical Waves in Attenuated Total Reflection Kretschmann Configuration with Nanostructured Langmuir-Blodgett Films

Surface plasmon (SP) emission light has been investigated for rhodamine-B (RB) dye Langmuir-Blodgett (LB) films on silver (Ag) thin film in the attenuated total reflection (ATR) Kretschmann configuration by means of reverse irradiation of a laser beam. Emission light through the prism was clearly observed for the configuration of prism/Ag/LB films corresponding to the resonant excitation conditions for SPs using the reverse irradiation. The intensities of the SP emission light increased with the thickness of the RB LB films, but nonlinear reductions of the SP emission light and photoluminescence (PL) were observed due to nonradiative energy transfer at the very small separations between the RB and Ag films. It is thought that the SPs, that is, two-dimensional optical waves, are excited by PL of the RB dyes on the Ag film and that this phenomenon is very useful for applications utilizing dye molecules on metal thin films.

Surface Plasmon Excitations and Emission Light due to Molecular Luminescence on Metal Thin Film

ABSTRACTEmission light due to surface plasmon (SP) excitations has been investigated in Kretschmann configuration of prism/metal thin film/organic dye thin films by means of direct irradiation of a laser beam from air to the films. Emission light through the prism coincided with the resonant conditions of SP excitations in the configuration. It was thought that SPs on the metal surface were excited by luminescence of dye molecules close to the metal surface, and the SPs propagating along the metal surface were converted to the emission light according to the resonant conditions of SPs in the configuration. Intensities and spectra of the SP emission light through the prism strongly depended upon emission angles, nanostructures of dye films, the film thickness and mixture of two kinds of dyes.

ナノ構造制御ローダミンＢ ＬＢ膜のホトルミネッセンスとクレッチマン配置での表面プラズモン放射光

Photoluminescence and surface plasmon emission light have been investigated in the attenuated total reflection (ATR) Kretschmann configuration. Surface plasmons (SPs), two-dimensional optical waves, were excited when rhodamine-B (RB) dye Langmuir-Blodgett (LB) films on metal thin film were directly irradiated by laser beams in the Kretschmann configuration. Emission light, that is, three-dimensional optical waves through the prism were observed corresponding to the resonant conditions of SP excitations in the configuration. The intensity of the SP emission light was small for the RB LB film with 4 layers, but the intensities increased in proportion to the thickness for the LB films having above 8 layers. Photoluminescence intensities also strongly depended upon the nanostructured separation between the RB LB films and metal thin films. It is thought that the phenomena are very useful for applications utilizing dye molecules on metal and conversion between three- and two-dimensional optical waves.