Geometrical condition for observing Talbot effect in plasmonics infinite metallic groove arrays

Abstract

The plasmonics Talbot effect in metallic layer with infinite periodic grooves is presented in this study. Numerical approach based on the finite element method is employed to verify the derived Talbot carpet on the non-illumination side. The groove depth is less than the metallic layer thickness; however, for specific conditions, surface plasmons polaritons (SPPs) can penetrate through grooves, propagate under the metallic layer, and form Talbot revivals. The geometrical parameters are specified via groove width, gap size, period, and wavelength, and their proper values are determined by introducing two opening ratio parameters. To quantitatively compare different Talbot carpets, we introduce new parameters such as R-square that characterizes the periodicity of Talbot images. The higher the R-square of a carpet, the more coincident with non-paraxial approximation the Talbot distance becomes. We believe that our results can help to understand the nature of SPPs and also contribute to exploring this phenomenon in Talbot-image-based applications, including imaging, optical systems, and measurements.

Galyum Katkili Çi̇nko Oksi̇t Nanoanten İle Mi̇krolens

“…As mentioned above, the prominence of the Talbot effect can also relatively reduce the efficiency of the primary focus for Sample#2.3, Sample#2.4, Sample#2.5, Sample#2.6, Sample#2.7, and Sample#2.8. According to Talbot phenomenon, scattering optical fields can exactly copy the pattern of a periodic structure at multiple distances, under illumination by a monochromatic plane wave (Talbot, 1836;Dennis et al, 2017;Li et al, 2017;Rayleigh, 1881;Mehdi et al, 2018a;Mehdi et al, 2018b;Wen et al, 2013). In ordinary Talbot effect, Talbot revivals are generated at the distance named as Talbot distance for each copied device pattern (Talbot, 1836;Dennis et al, 2007;Li et al, 2017;Rayleigh, 1881;Mehdi et al, 2018a;Mehdi et al, 2018b;Wen et al, 2013).…”

“…Periodic metallic nanostructural arrays exhibit a complex coupling behavior between localized surface plasmon resonance (LSPR), Bloch wave surface plasmon polaritons (BW-SPPs) and Wood anomalies especially at optical frequencies due to their arrangements (Yu et al, 2013). Thus, a focusing fact related with a plasmonic Talbot effect observed under paraxial (Mehdi et al, 2018a) or non-paraxial (Mehdi et al, 2018b) conditions. Accordingly, non-paraxial and paraxial formulas between surface plasmon wavelength  and Talbot distance can be given as = 1−√1−( ⁄ ) 2…”

Observation of Plasmonics Talbot effect in graphene nanostructures

“…Using differential contrast based on interference, they observed the effect of non-paraxial approximation in gold nanoparticles. Gold nanoparticles with a period of 600 nm and a diameter of 120 nm were placed in water with a refractive index of 1.33., then obtained the interference pattern of the polarized light beam from the laser with the periodic structure of gold nanoparticles in the state of interaction at the excitation wavelength of 600 nm, they obtained the dark and light areas caused by light beam and nanoparticles interaction at the height of 50 nm, leading to the resonance peak of local surface plasmons 17 . The effect of surface plasmons in a structure based on grooved silver metal nanoparticles which their gap is smaller than the penetration depth of surface plasmons is separated from surface plasmons based on the non-paraxial approximation.…”

Design and Demonstration of an In-Plane Micro-Optical-Electro-Mechanical-System Accelerometer Based on Talbot Effect of Dual-Layer Gratings

“…When the collimated laser irradiates the dual-layer gratings, it will form a self-generated image of the grating pattern in the Z-direction at periodic intervals, which is called the Talbot effect as shown in Figure 2 a. The periodic repetition of the field distribution in the near field of the grating can be seen through the Talbot effect transmitted by the gratings [ 26 , 27 , 28 , 29 ]. According to the theory of near-field diffraction gratings [ 30 ], the self-generated image is repeated with a Talbot period of approximately [ 31 ] and the Talbot imaging region is within /4, where d is the spatial period of the grating, λ is the wavelength of the incident light and N is the number of cycles of the laser beam passing through the grating.…”