Resonant absorption and scattering in evanescent fields

Optical resonances of indium islands on GaAs(001) observed by reflectance anisotropy spectroscopy

“…Since there is a small but finite deviation of a few degrees in the incidence angle from normal incidence, one might suspect that a difference in geometrical resonance conditions for s-and p-polarized light is responsible for the observation. 4 This assumption was checked by measuring the dependence of the RAS spectra of one sample for ͑i͒ different incidence and reflection angles of the light and ii͒ for different angles between the right-angled polarization vectors of the light and the surface directions ͓110͔ and ͓110͔. The results can be summed up as follows: ͑a͒ neither the amplitudes nor the positions of the maxima and respective minima depend on the incidence angle and ͑b͒ by rotating the sample 45°a round the normal to the sample surface, the optical anisotropy vanishes completely and by rotating 90°it reverses sign.…”

“…In the past few years, the use of these resonances for resonance enhanced spectroscopy, due to the high localfield enhancement at the surfaces of the particles, and the potential of Mie resonances for optical size analysis have attracted considerable interest. 4 In this paper, we report on optical resonances in the Mie regime (kaӍ1) detected by the polarization state of light, a topic hardly studied so far. The polarization state of the light backscattered from metal islands on a semiconductor surface has been determined by reflectance anisotropy spectroscopy ͑RAS͒.…”

<title>Near-field Mie scattering in optical trap nanometry</title>

“…10 MDR resonance has been observed in plane-wave Mie scattering for larger dielectric particles ~10 µm, [11][12][13][14][15] and they are evident in the calculations of differential scattering cross sections in near-field Mie scattering by other researchers. 5,7,8 To investigate how changes in particle morphology affect near-field Mie scattering, scattered intensity into upper halfspace of the particle is calculated. Fig.…”

“…In previous scattering cross section calculations, [5][6][7][8][9] for near-field Mie scattering by dielectric particles, morphology dependent resonances (MDR) are evident when particle size is approaching and exceeding illumination wavelength. It is found that MDR structure depends strongly on the penetration depth of the incident near-field wave, 7 but the peak positions and half widths are unaffected by the kind of excitation (plane wave or near-field wave).…”

“…1). [5][6][7][8][9] However, to apply near-field Mie scattering into an imaging process such as optical trap nanometry knowledge of scattered electromagnetic field at any point around the particle is needed. Therefore we have developed a mathematical model from the analytical solution for near-field Mie scattering 6,7 which enables us to calculate scattered electromagnetic field at any point around the particle.…”