What types of grating analysis is GSOLVER best suited for?
GSOLVER was originally built for analysis of grating structures with no known analytic eigensolution. Structures in dielectrics (waveguide couplers, subwavelength antireflection gratings, etc.) with complicated material structures were the target problems. This required that the GSOLVER interface and algorithm be driven by the most general point of view. The classic class of gratings (blazed in metal) is known to have analytic eigensolutions. Spectroscopist working in instrument design constrained by classical approaches are encouraged to apply those methods as one would expect that exact solutions offer more robust calculational approaches. On the other hand, as modern lithographic and coating techniques expand beyond the semiconductor fabs, new design freedom becomes available to the optical designer. One usually is interested in maximizing (or minimizing) efficiency and dispersion. The past decades have seen the development of dielectric grating structures that exceed the efficiency
