[9a-Z16-2~6] 4.1 Plasmonics and Nanophotonics

▲ [9a-Z16-6] Surface plasmon resonance-induced Goos-Hänchen shift due to gold film

〇(D)Cherrie May Olaya^1,2、Norihiko Hayazawa^1,2、Nathaniel Hermosa¹、Takuo Tanaka^1,2 (1.Univ. of Philippines、2.RIKEN)

キーワード：Goos-Hanchen shift, surface plasmon

We measured large angular Goos-Hänchen (\Theta_{GH}) shift induced by the reflectivity changes at surface plasmon resonance (SPR) of 50-nm thick gold (Au) film. Reflectivity measurements showed resonance angle at 44.4 ^\circ which agree well with our calculations. Due to the propagation dependence of \Theta_{GH}, the magnitude of \Theta_{GH} could be controlled by controlling beam parameters. We show an inflection point at the SPR angle and a maximal shift of around 300\mu m for measured by a position-sensitive detector positoned 4.5 cm from the beam waist. Deviations from calculated values could be attributed to the presense of titanium (Ti) layer which served as an adhesion layer and the roughness of the sample surface. Our work shows that measurement of GH shift could provide control over SPR detection by changing beam parameters.