Electromagnetic scattering and absorption by randomly oriented fibers

Abstract

In this paper, we numerically calculate the extinction, scattering, absorption, and radar cross sections for a randomly oriented finite conducting fiber. Calculations in the long (centimeter) and short (infrared) wavelengths are presented and compared with the fixed orientation value when the incident electric field is aligned along the fiber length. The calculations presented in this paper are necessary for the parametrization of fibers to play the role of efficient obscurant and anti-radio frequency interference.

Anomalous Extinction Efficiency of Two Dimensional Particles in the Visible

“…Figure 5 shows the extinction efficiency for a silver disk with thickness 20 nm at λ = 500 nm for broadside incidence and incidence angles 25, 45, and 65 degrees at parallel polarization. We notice that extra resonances occur for oblique incidence between the two main resonances of the broadside incidence, and a similar behavior was also seen for fibers [3].…”

“…Figure 6 shows the orientational average extinction cross section per unit mass for a silver disc with thickness 20 nm at the resonant diameter of d = 88 nm as a function of wavelength. Also we plot the behavior of a silver fiber [2,3] with diameter 20 nm at the resonant length (at λ = 500 nm) and the behavior of a resonant silver sphere at λ = 500 nm [22][23][24]. The diameter of the sphere and the length of the fiber were chosen to give the maximum efficiency (resonant) at λ = 500 nm.…”

“…Also we will test the fundamental upper limits reported by Miller et al [27,28] for the nanodisks material and extend the theoretical work by Langhammer et al [16] to nanodisks beyond the quasistatic approximation (i.e., for disks comparable or larger than the wavelength). CWW code has been used to perform the calculations in this study along with the Mie scattering theory for spheres [13,22] and our developed and tested code for fibers [3].…”

“…Particle's shape, size, and material contents effects on the attenuation efficiency have been investigated theoretically and experimentally across the electromagnetic spectrum in search for the best attenuation particle candidate. Theoretical and experimental research on particles that are essentially one dimensional (i.e., fibers) and can have high mass or volume normalized attenuative properties at either long (centimeter) or short (visible and infrared) wavelengths have been reported in recent decades [1][2][3][4][5][6][7][8][9][10][11][12], where both analytical [1] and numerical [2,3] solutions of the problem of electromagnetic scattering and absorption by fibers have been developed and verified experimentally [7][8][9][10][11][12]. Two dimensional particles (i.e., thin discs) have been extensively studied across the electromagnetic spectrum [13][14][15][16][17][18][19][20][21].…”