International Journal of Scientific Research and Management (IJSRM) ||Volume||10||Issue||11||Pages||P-2022-20-24||2022|| Website: www.ijsrm.in ISSN (e): 2321-3418 DOI: 10.18535/ijsrm/v10i11.p01 Vincensius Gunawan, IJSRM Volume 10 Issue 11 November 2022 [www.ijsrm.in] AL-2022-20 The calculated attenuated total reflection (ATR) for analyzing surface plasmon polaritons Vincensius Gunawan Physics Department, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto, Tembalang, Semarang, Indonesia Abstract The electromagnetic waves propagate in the interface between metal and dielectric can be simply called surface plasmon polariton. The surface plasmon polaritons were produced by the coupling of incoming electromagnetic waves and collective vibrations of free charges on metal surface. The generation of surface polaritons may be done using attenuated total reflection (ATR) method which was based on total internal reflection. The method can be performed numerically by analyzing reflections on each involved inter faces.The generated surface plasmon polaritons were represented by the appearance of the dip in the ATR spectroscopy. In this paper, we presented the ATR spectroscopy for surface plasmon polaritons generated on gold-castor oil interface. The results showed the predicted dispersion relation from calculated ATR of the surface plasmons polaritons were in good agreement with the dispersion relation from the theory. Keyword: dispersion relation, plasmon polaritons, attenuated total reflection Introduction Surface plasmon polaritons (SPP) were electromagnetic waves, which propagate along the interface between dielectric and metal. Here, metal is an active medium, which provides collective free electron vibrations while dielectric is a passive medium that maintain electric fields at the interface. The features of SPP had already reported in the early of 20th century (Wood, 1968; Garnet, 1904; Mie, 1908). Since then, the SPP have received high attention due to its potential application such as: biosensors using plasmonic metamaterials (Kabashin et al., 2010), data storage capable to store data in the scale of terabits cells using plasmonic near-field transducers (O’Connor et al., 2009), wave-guides by fabricating patterned structure of metals and silicon (Nagpal et al., 2009) and also solar cells in increasing absorption by grooving Si thin film (Ferry et al., 2008). There were several methods to excite SPP, such as gratings method, diffraction of roughness surface (Zayats et al., 2003; Zhang et al., 2012) and attenuated total reflection (ATR) (Otto, 1968; Kretchmann et al., 1968). The concept of ATR method based on the total internal reflection. Hence, it is required a high index prism to produce evanescent waves which then excite SPP at the interface between dielectric and metal. The ATR have used to study the properties of polaritons in several materials both experimentally and numerically. Analisis of both surface and bulk polaritons in dielectrics were analyzed using ATR method (Borstel et al., 1974). Surface phonon polaritons on the surface of dielectric GaN were studied using ATR (Torii et al., 2000). The ATR method is applied in explaining magnon polaritons in magnetic FeF 2 (Jensen et al., 1995; Jensen et al.,1997). The reciprocal property of surface polaritons on the surface of semi-infinite multiferroics was shown in ATR spectroscopy (Gunawan et al, 2011). The existence of surface polaritons on multiferroic film were also predicted numerically using calculated ATR (Gunawan et al., 2017; Gunawan et al., 2021). The ATR spectroscopy was obtained by measuring the ATR reflectance. The sharp dip in ATR spectroscopy represents the existence of surface polaritons. The dip’s frequency and the related vector propagation lead to the point at dispersion relation curves. Then, if we vary the vector propagation of initial electromagnetic waves by changing the initial angle, the set of related surface modes frequency can be obtained. Hence, the part of surface polariton’s dispersion relation can be constructed using the resulted data. The dispersion