No abstract

No abstract

No abstract

In this paper, we present a formulation of a finite‐difference vector beam propagation method for an isotropic open chiral slab waveguide. This method allows the analysis of wave propagation on a chiral slab waveguide whose structure varies along the propagating direction. Numerical results show that the proposed method works successfully. Using this method, we present two interesting examples of numerical calculation. One is the phenomenon that the first mode is converted to the third mode by a tapered chiral waveguide. The other is the phenomenon that the TE mode is converted to the TM mode by a straight chiral waveguide. © 1998 Scripta Technica, Electron Comm Jpn Pt 2, 81(1): 21–31, 1998.

SUMMARYFor a highly information-oriented society, further enhancement of the capacity and speed of communications and information systems is necessary. For this purpose, all-optical logic elements are expected as a promising solution. In this paper, structures of new all-optical logic elements using a nonlinear medium with its index of refraction varying with the optical intensity are proposed and their properties are analyzed. Most of the all-optical logic elements based on nonlinear materials proposed to date either make use of more than two wavelengths or require a specific phase condition (such as 0° or 180°) for combined lightwaves with identical wavelengths. It is extremely difficult to fix the phase difference between the two lightwaves to be combined. This is a significant problem in practical fabrication. In this paper, all-optical logic elements are proposed in which only one wavelength is used and no specific phase relationship is required. For the numerical analysis, the FD-BPM (Finite Difference Beam Propagation Method) based on the Padé (1, 1) approximation is used.