The simulation of diffractive optical structures allows for the efficient testing of a large number of structures without having to actually fabricate these devices. Various forms of analysis of these structures have been done through computer programs in the past. However, programs that can actually design a structure to perform a given task are very limited in scope. Optimization of a structure can be a task that is very processor time intensive, particularly if the optimization space has many dimensions. This thesis describes the creation of a computer program that is able to find an optimal structure while maintaining a low-dimensional search space, thus greatly reducing the processor time required to find the solution. The program can design the optimal structure for a wide variety of planar optical devices that conform to the weakly-guiding approximation with an efficient code that incorporates the low-dimensional search space concept. This work is the first use of an electromagnetic field solver inside of an optimization loop for the design of an optimized diffractive-optic structure.

<p>Complex surface structures in nature often have remarkable optical properties. By understanding the origin of these properties, such structures may be utilized in metamaterials, giving possibilities to create materials with new specific optical properties. To simplify the optical analysis of these naturally developed surface structures there is a need to assist data analysis and analytical calculations with numerical calculations.</p><p>In this work an application tool for numerical calculations of optical properties of surface structures, such as reflectances and ellipsometric angles, has been developed based on finite element methods (FEM). The data obtained from the application tool has been verified by comparison to analytical expressions in a thorough way, starting with reflection from the simplest of interfaces stepwise increasing the complexity of the surfaces.</p><p>The application tool were developed within the electromagnetic module of Comsol Multiphysics and used the script language to perform post-process calculations on the obtained electromagnetic fields. The data obtained from this application tool are given in such way that easily allows for comparison with data received from spectroscopic ellipsometry measurements.</p>

Complex surface structures in nature often have remarkable optical properties. By understanding the origin of these properties, such structures may be utilized in metamaterials, giving possibilities to create materials with new specific optical properties. To simplify the optical analysis of these naturally developed surface structures there is a need to assist data analysis and analytical calculations with numerical calculations. In this work an application tool for numerical calculations of optical properties of surface structures, such as reflectances and ellipsometric angles, has been developed based on finite element methods (FEM). The data obtained from the application tool has been verified by comparison to analytical expressions in a thorough way, starting with reflection from the simplest of interfaces stepwise increasing the complexity of the surfaces. The application tool were developed within the electromagnetic module of Comsol Multiphysics and used the script language to perform post-process calculations on the obtained electromagnetic fields. The data obtained from this application tool are given in such way that easily allows for comparison with data received from spectroscopic ellipsometry measurements.