Body-of-revolution finite-difference time-domain modeling of space–time focusing by a three-dimensional lens

Abstract

We introduce a body-of-revolution finite-difference time-domain simulation capability that can be applied to rotationally symmetric linear-optics problems. This simulator allows us to reduce a computationally intractable, three-dimensional problem to a numerically solvable two-dimensional one. It is used to model the propagation of a pulsed Gaussian beam through a thin dielectric lens and the focusing of the resulting pulsed beam. Analytic results for such a lens-focused, pulsed Gaussian beam are also derived. It is shown that, for the same input energy, one can design ultrawide-bandwidth driving signals to achieve a significantly larger intensity enhancement than is possible with equivalent many-cycle, monochromatic signals. Several specially engineered (designer) pulses are introduced that illustrate how one can achieve these intensity enhancements. The simulation results confirm that intensity enhancements can be realized with properly designed ultrawide-bandwidth pulses.

Finite-Difference Time Domain Analysis of Ultrashort Pulse Laser Light Propagation under Nonlinear Coupling

“…In this paper, a Body of revolution (BOR) FDTD method (16) is developed with the added ability the nonlinear effect as Kerr effect, multiphoton absorption and plasma defocusing (11) .…”

“…where subscript ζ denotes r, φ and z. E ζk 1, E ζk 2, H ζk 1 and H ζk 2 are Fourier coefficients (16) . In this case, linearly polarized laser light is considered, and for a normally incident wave of only k = 1 mode is needed that is valid for our case.…”

Eigenmode analysis of optical waveguides by a Yee-mesh-based imaginary-distance propagation method for an arbitrary dielectric interface

“…The BOR technique [7] has often been employed for the FDTD analysis of axially symmetric optical elements [20], [21]. The use of the technique enables us to accurately describe the circular interface in the cylindrical coordinates based on Yee's mesh.…”

“…Consequently, the partial derivative in is performed analytically [7], [20], [21]. This means that the BOR technique reduces the original three-dimensional model to an equivalent two-dimensional one.…”

BOR-FDTD subgridding based on finite element principles

“…In this paper we report on our efforts to develop a suitable BOR-FDTD subgridding technique which can of course be used outside the context of plasma research. For an introduction to BOR-FDTD we refer to Chapter 12 of [1] and to e.g., [8,9,10,11,12]. Subgridding has been thoroughly investigated in the past [13,14,15,16,17,18,19,20,21,22,23].…”