Title :
Study of Coupling Length of Concentrically Curved Waveguides
Author :
Cai, Dong-Po ; Chen, Chii-Chang ; Lee, Chien-Chieh ; Wang, Tsong-Dong
Author_Institution :
Dept. of Opt. & Photonics, Nat. Central Univ., Jhongli, Taiwan
Abstract :
In this paper, we propose a method based on Helmholtz equation to determine the coupling length of the light propagating in concentrically curved waveguides by the conformal transformation. After the transformation, the concentrically curved waveguides are regarded as straight directional couplers, and the coupling length can be obtained rapidly by using this method. We also calculate the coupling length by the finite-difference time-domain (FDTD) method to compare with the result obtained by our method. The results show a good agreement between the coupling length obtained by the conformal transformation and the FDTD method.
Keywords :
Helmholtz equations; finite difference time-domain analysis; light propagation; optical directional couplers; optical waveguides; FDTD method; Helmholtz equation; concentrically curved waveguides; conformal transformation; coupling length; finite-difference time-domain method; light propagation; straight directional couplers; Couplings; Finite difference methods; Indexes; Optical waveguides; Refractive index; Time domain analysis; Waveguide transitions; Concentrically curved waveguides; conformal transformation; coupling coefficient; coupling length;
Journal_Title :
Photonics Journal, IEEE
DOI :
10.1109/JPHOT.2011.2178063
