Authors: W. Bogaerts, P. Bienstman, D. Taillaert, R. Baets, D. De Zutter
Title: Out-of-plane scattering in 1D photonic crystral slabs.
Published in: Optics and Quant. Electron. vol. 34, p. 195-203,(2002)
We present a detailed study of out-of-plane scattering losses in a 1D approximation of 2D
photonic crystal slabs. In 2D photonic crystals with a waveguide structure in the third
dimension, the periodic structure (in a lot of applications a 2D arrangement of holes etched
through the core and cladding) will cause light to scatter out of the waveguide plane. We
studied the out-of-plane scattering losses of these holes using a 2D approximation of this 3D
structure, with etched slots instead of holes. Our simulation techniques included mode
expansion with PML and FDTD. We will present the influence of the refractive index
contrast between core and cladding of the layered structure. We show that the losses increase
with higher index contrast between core and cladding, but that with very high index contrasts
and under the right circumstances light can be coupled into lossless Bloch modes.
Key Words: Photonic Crystals, Out-of-plane Scattering, Guided Bloch mode