Sammendrag
Electrooptic (EO) materials are used to transform electric information into optical information or to perform specific optical functions using an electric signal as the stimuli. A number of ceramics have been shown to possess this quality; lithium niobate (LN) or tantalate, potassium dihydrogen phosphate, barium titanate and lead lanthanum zirconate titanate (PLZT) are some examples. Among these, lithium niobate in its single crystal form, is the material that is commercially exploited today. PLZT has a much higher EO effect than LN and can also easily be fabricated in a useful thin-film format, e.g. by chemical solution deposition (CSD). CSD provides several advantages for production of films for optical applications due to excellent stoichiometry control, high elemental homogeneity, easy introduction of substituents and low processing temperatures. The fabrication of PZT thin films by CSD has been optimized during the last 10 years due to PZT’s use as piezoelectric active components in MEMS systems. High quality PZT thin films with excellent piezoelectric and dielectric properties can now be fabricated [2-4]. The high electromechanical quality of such films can be attributed to phase purity, compact microstructure and improved texturing. Incidentally, these qualities are also important for obtaining low optical loss in thin films. But still, making low-loss, EO waveguides using CSD is not yet an established technology. The goal of the present project is to design and fabricate a Mach-Zehnder wave-guide with PLZT, fabricated by CSD, as the wave-guiding layer. The wave-guide design is based on results from a pre-study of the optical properties of PLZT as a function of stoichiometry and texture combined with results from simulations. We will present the results of the pre-study, the simulations and the final wave-guide with its properties at this stage. [1] P. Muralt, T. Maeder, L. Sagalowicz, S. Hiboux, S. Scalese, D. Naumovic, R.G. Agostino, N. Xanthopoulos, H.J