Numerical investigation of characteristics of laser radiation scattered in an integrated optical waveguide with three-dimensional inhomogeneities

Abstract

Specifics of theoretical analysis of wave phenomena in irregular integrated optical waveguides are investigated. The object of the investigation and the main types of irregularities (smooth, statistical, and sharp) are described. The goals of the numerical modeling are formulated. The structure of the program and the general structure of the algorithm allowing numerical investigation of guided modes' scattering from 3D irregularities of an integrated optical waveguide are described. The dispersion relations of the TE and TM modes of the integrated optical waveguide under investigation, as well as field patterns of the radiating TE modes of the substrate and the laser radiation scattered from the three dimensional guiding layer inhomoge neities of an integrated optical waveguide, are presented. The results are analyzed in detail. The methods developed can be used for numerical investigation of the characteristics of laser radiation scattered in various optical waveguides with three dimensional irregularities.

Irregular liquid crystal waveguide structures: analysis of quasi-stationary fluctuations, power loss and statistical properties of irregularities.

“…A more detailed analysis of an inverse waveguide scattering problem and these quasi-stationary effects (due to the director motion) are beyond the scope of this work (see e.g. [6][7][8][9][10][11]).…”

“…To improve the obtained results, especially when irregularities change from small-scale (≈ 0.1-10 μm) to large-scale (≈ 20-100 μm), one need to use in the numeric analysis the analytic solutions of the problem of waveguide propagation, diffraction and scattering of electromagnetic monochromatic radiation in 3D-irregular and smoothly-irregular waveguides and waveguiding structures [7][8][9][10][11][14][15][16][17][18][19][20][21][22][23].…”

“…Thus, the obtained estimate confirms the correctness of the experimental dependences found by us. Since the correlation radius ef r decreases, both I and the damping coefficient  decrease, which was discovered in the experiments.The use of the phenomenon of waveguide 3D scattering made it possible to substantially increase the resolution by the correlation radii in comparison with the classical methods such as the optical microscopy, interferometry, difractometry and ellipsometry[7][8][9][10][11]. In addition, the waveguide method made it possible to obtain statistical information on waveguide irregularities in one measurement with a sufficiently large volume of the waveguide layer.…”

Pulse distortion caused by waveguide inhomogeneity in nonlinear optical wavelength converters

“…An accurate study of the inhomogeneity along or across the optical waveguides was also presented, without considering the effects on nonlinear processes 14 . In another study, the effects of 3-dimensional scatterers on the propagating optical waves were examined, too 15 . In addition, the effects of inhomogeneities on nonlinear integrated optical components were studied by Janet Jackel 16 where the main focus was on the relative sensitivity of interferometers and directional couplers.…”