Liquid Crystal Filled Polymer Structure (LiCFiPS) Devices consist of a polymer structure, which performs the desired spatial phase modulation of the incident light, filled with liquid crystal to permit modulation of this optical function. Fabrication of this type of device may be carried out at very low cost using established polymer embossing techniques. Devices with the liquid crystal aligned in the plane of the device and along the polymer faces have shown good quality optical switching. However regions with the liquid crystal aligned perpendicular to the grating lines show defects and inhomogeneities which give rise to spurious optical effects. To better understand the factors influencing the alignment of the liquid crystal computer modelling has been used to simulate the orientation of the liquid crystal director within such devices. The field within the device and orientation of the liquid crystal were calculated iteratively using the Landau-De Gennes form of the free-energy equation. The computational models of these devices show features that correspond well with the observed switching characteristics of actual devices. The features and changes that eradicate the defect provide insight into how the device configuration might be improved. While such devices might not offer the ultimate versatility of matrix addressed devices they do offer switchable optical devices of complex functions at very low cost.