Guided mode resonance filters (GMRF) combine subwavelength gratings and planar slab waveguides to create highly efficient, narrow linewidth spectral filters. Resonances between diffracted orders of the SWG and the waveguide provide the mechanism for spectral filtering. These resonance conditions are dependent on all of the structural and optical parameters of the GMRF structure. Microfabrication technologies are routinely used to fabricate these types of micro-optical structures as well as other types of micro-optical components such as diffractive optical elements. A spatially and spectrally varying optical element can be realized by spatially varying one or more of the structural parameters of a standard GMRF structure. This dissertation will show different methods of achieving a spatially and spectrally varying GMRF. These types devices have applications as beam shaping elements, feedback elements is laser systems, and as an alternate to graded reflectivity mirrors. Unlike graded reflectivity mirrors, the spatial variation in these space variant GMRFs is not limited to axial symmetries. This dissertation will focus on space variant GMRFs through a spatially variation in the fill-fraction of the SWG lattice structure as well as a spatial variation of the waveguiding layer. It will be shown what the effect of each of these variations has on the resonance conditions of a GMRF. Proposed devices for a spatially varying waveguide structure using a silicon oxide SWG with a silicon nitride waveguiding layer and a silicon nitride SWG with a silicon nitride waveguide layer will be discussed
