Gsolver Information

Grating Solver Development Company was founded in 1994 by Dr. David Fluckiger to provide a diffraction grating analysis tool that would run on a PC. The result was GSolver V1.1. Initially the code was used to design high frequency gratings to provide antireflection surfaces (subwavelength crossed grating) in materials that are difficult to index match. This required full three dimensional vector solutions to the diffraction problem. Since that time the code has been extended with a general user interface, and many code improvements. GSolver is intended to be used for design of novel diffractive structures in dielectrics and metals built with semiconductor manufacturing tools, including photolithographic techniques. These techniques imply finite planar feature sizes and indicate a piecewise constant diffraction grating structure. The piecewise constant approximation is central to the coupled wave approach to the solution of Maxwells equations in the grating region. Maxwells equations, together with a Fourier expansion of the permitivity (and impermitivity) generate an infinite set of first (or second) order coupled linear differential equations which can be solved by standard algebraic eigensystem methods. The evolution of GSolver parallels the evolution of the PC. As hardware and compiler technology have advanced, so also has GSolver. GSolver is ideally used as a design tool for linear piecewise constant grating structures in dielectrics and metals. The algorithms are numerically stable, even for very deep gratings. GSolver is not generally recommended for analysis of classic spectroscopic (high order blazed) gratings in metals. These types of grating support large numbers of evanescent orders and are better handled (numerical stability) by codes designed for specific piecewise linear boundaries. Limitations of GSolver are due to finite precision arithmetic in 64 bit floating point hardware (PC environment). Higher floating point precision is included in GSolver through software emulation of IEEE floating ...