Propagation constants of weakly guiding optical fibers with arbitrary shapes can be efficiently calculated through a limited circular Fourier expansion of the wave equation, with a direct numerical integration.
© 1989 Optical Society of America
Ye-Heng Wang and Charles Vassallo, "Circular Fourier analysis of arbitrarily shaped optical fibers," Opt. Lett. 14, 1377-1379 (1989)