Try
WAVEGUIDE
before you try Modeig because it's better and more user friendly
Modeig98 On-Line Reference Congratulations on your
choice of optical waveguide modeling programs. Originally
written by Robert B. Smith in 1977. MODEIG is used to
calculate complex propagating modes in arbitrary,
plane-layered, complex dielectric structures and devices,
such as optical waveguides and multiple quantum well
lasers. The MODEIG98 update
encompasses converting the program code to the FORTRAN 90
programming language thereby enabling cross platform
compatibility, as well as the addition of subroutines to
calculate the index of refraction for a variety of
materials systems. 
Release 1.1 is HERE! 