Highly accurate vector correction for optical waveguide propagation constants

T.M. Benson, P.C. Kendall, M.A. Matin, M.S. Stern
1993 IEE Proceedings J Optoelectronics  
A vector correction is derived to the propagation constants obtained from a polarised analysis of graded-index optical waveguides. This general formula is reduced to a form suitable for use with semiconductor rib and strigloaded waveguides. Corrected propagation constants calculated for a range of semiconductor rib waveguide structures coincide with available results from a full vector approach. Moreover, the vector correction term is always small, underpinning the accuracy of the simple and
more » ... t polarised approach for the first time. Introduction The rapid and successful development of optical communication systems has motivated interest in modelling and analysis of a wide range of optical-waveguide structures. Semiconductor strip or rib waveguides have received particular attention over the last few years because of their relatively simple fabrication in the context of planar technology. Advanced processing techniques allow excellent control over the composition and geometry of experimental waveguide cross-sectional profiles, and this has in turn created increased interest in the theoretical analysis of these waveguides. As far as semiconductor rib waveguides are concerned, early structures were nearly all of small etch depth, and relatively simple analysis techniques such as the effectiveindex method [l, 2) su&ced. Present day structures rely on sophisticated layered structures and deeper etch depths, however, calling for better analysis techniques [3, 41. Accurate knowledge of mode propagation constants and field profiles is also essential for the study of structures such as directional couplers [5-71 and in the calculation of roughness scattering and curvature losses [9-111. 0 IEE, 1993 Paper 9269J (E13). first received 28th April and in revised form 1st T.M. Benson and M.A. Matin are with the
doi:10.1049/ip-j.1993.0017 fatcat:wf2yaq6ljbbchlxcl2nkusob6a