RIGOROUS ANALYSIS OF MICRO- NANO-STRUCTURES USING FMM

Introduction:
Fourier Modal Method (FMM) is also known as rigorous coupled-wave analysis (RCWA). It is widely used for the accurate analysis of electromagnetic waves diffracted by periodic structures in the scale of wavelength. It can be used for both holographic and surface-relief grating structures with planar and conical diffraction. It is an efficient and exact solution of Maxwell's equations for the electromagnetic diffraction. The accuracy of the solution obtained depends solely on the number of the terms in the field expansion which are related with the number of evanescent orders, in the condition that the conservation of energy always should be satisfied.

Our interest/target:
Fourier Modal Method (FMM) is already implemented in the optical design software VirtualLab to analyze the periodic gratings. Concerning the aperiodic structures, the so-called Perfectly Matched Layer (PML) should be implemented into FMM and then into VirtualLab. This is our current interest/target.

diffractive efficiency diagramm  electric field
                                            (a)                                                                            (b)
Figure 1: (a) Diffractive Efficiency Diagram; (b) Electric field inside the grating