Rs. Burton et Te. Schlesinger, COMPARATIVE-ANALYSIS OF THE METHOD-OF-LINES FOR 3-DIMENSIONAL CURVED DIELECTRIC WAVE-GUIDES, Journal of lightwave technology, 14(2), 1996, pp. 209-216
We discuss the effects of waveguide geometry on the radiation loss of
tightly curved multimode dielectric waveguides. Three waveguide geomet
ries are investigated: a ridge waveguide, a buried waveguide, and an i
nterdiffused waveguide, We compare the effective index method with bot
h semi- and full-vectorial method-of-lines analyses for these waveguid
e geometries. This comparison shows that the effective index method is
accurate for curved waveguides except where the outer confinement reg
ion is in cut-off or, in the case of TM-polarization, for the ridge wa
veguide, In the latter case, the full-vectorial method-of-lines predic
ts a resonant feature of the TM-mode radiation loss of curved ridge wa
veguides; this is not predicted by either the semivectorial method-of-
lines or the effective index method.