Reducing radio frequency (RF) transmission loss is a key requirement when fabricating GaN‐on‐Si RF devices. To get a better insight into the RF loss mechanism in the GaN‐on‐Si structure, the RF loss of an AlN/Si template is investigated by varying the growth temperature of AlN during a metalorganic chemical vapor deposition process. The results show that the RF loss of the AlN/Si template is dominated by the interface loss due to the p‐type conductive channel at the AlN/Si interface, which is induced by the thermal diffusion of Al during the high‐temperature growth. Although a low growth temperature of the AlN nucleation layer can suppress the RF loss in the AlN/Si template, it results in a low crystalline quality of AlN for practical use. Optimizing the growth temperature of the AlN nucleation layer is essential to obtain a good balance between the crystalline quality, morphological quality, and RF loss such that the AlN/Si template is suitable for epitaxial growth of the complete GaN‐on‐Si RF device structure.

We provide insight into the driving mechanisms and requirements to create an electro-optic spatial light modulator based on a Barium Titanate waveguide and an optically transparent electrode cladding layer. We have developed a generic framework of electric field simulations and non-linear optics to create any desired modulation in an area of interest, applicable for liquid crystals, Pockels and Kerr cells. Targeting our device structure, we have evaluated several design parameters of the arbitrarily reprogrammable SLM, capable of optical beamforming and high-quality holograms.