Cm. Kim et Ms. Chung, EIGENVALUE EQUATIONS OF N-PARALLEL GRADED-INDEX WAVE-GUIDES - WKB ANALYSIS, IEEE journal of quantum electronics, 33(9), 1997, pp. 1608-1613
The eigenvalue equations of N-parallel graded-index waveguides are der
ived in a recursive form for the first time by using the WKB method an
d the transfer matrix method, For the derivation, trial solutions are
defined which ndt only converge at turning points but also approximate
the conventional WKB solutions, It is confirmed through the computer
simulation that the results of the derived WKB eigenvalue equations ar
e in good agreement with those of the finite-difference method in the
well-guided regions.