Abstract:

A leastsquares method was proposed for grating diffraction. Based on the partition of the computational domain, the local property of the solution is approximated by plane wave functions, and the property of the solution toward infinite is represented by a truncation of the Rayleigh expansion.
 The method with a fast convergence rate is easy to apply and needs few elements. It is appropriate to normal diffraction gratings and the cases with large wave number. Numerical examples show the effectiveness of the approach.

Key words: grating diffraction, Rayleigh expansion, plane wave function