Optical field and attractive force at the subwavelength slit

Abstract

In recent works, a novel light-induced attractive force was predicted between two metal plates. This force arises by the interaction of surface plasmons which are excited at the metal when a transverse magnetic mode propagates through a subwavelength slit between two metal bodies. In this paper, the analytical and numerical calculations of this magnetic field are presented for the perfect metal and for gold. The amplitude and the phase transient curves between the known limiting cases of narrow and wide slits compared to the wavelength are found. The curve is shown to oscillate due to the emergence of new waveguide modes. The analytic solution for the perfect metal is in agreement with the computation for gold by means of the finite element method. The simple asymptotic formula for the light-induced attractive force is found in the limit of a narrow slit.

Effects of imperfect angular adjustment on plasmonic force

“…In the opposite case waveguide modes are excited, and then decrease the amplitude h 0 of field at the slit entrance [15]. Plasmons are generated at the surface of metal with dielectric…”

“…If the plates are infinite along z the unperturbed force per unit length in y-direction of is wider slit h 0 has oscillating -dependence die to excitation of higher waveguide modes [15].…”

“…As it was shown for perfect conductor, in the case of sub-wavelength slit and normal incidence it is sufficient to consider only the first mode, and the others are negligible [15,24].…”

Light scattering by dielectric bodies in the Born approximation

“…Strong coupling via evanescent wave is the key feature, which most practical nanophotonics tasks focus on. They include light energy concentration within few-nanometer range 4 ; highefficiency broad-band solar cells 5 ; light-induced forces at nano-scale 6,7 ; surfaces-enhanced Raman spectroscopy 8 ; the tomographic reconstruction of a nano-structure. 9 Only few problems allow analytical solution in photonics.…”

Влияние Юстировки На Плазмонную Силу В Субволновой Щели

“…Однако на пороге превращения моды в распространяющуюся волну ее роль возрастает за счет интерференции с нулевой модой, что приводит к резкому уменьшению силы вплоть до перехода от притяжения к отталкиванию. Показано, что порог в золоте отличается всего на несколько процентов от предельного случая идеального проводника [7].…”