Research Terms
Ceramic Engineering Ceramic Materials Physical Sciences Spectroscopy
Industries
Researchers at the University of Central Florida have developed a low-cost, non-toxic cladding material that suppresses the unwanted effects of transverse and parasitic oscillations that occur with high-powered lasers. The new cladding resolves the key performance issues associated with solid-state, single-crystal and ceramic laser amplifiers of such lasers.
Technical Details
The invention comprises a cladding material and methods for forming the cladding and using it to suppress transverse oscillations in solid-state, single-crystal or ceramic laser amplifiers. The cladding material is the same as the core (amplifier) material; for example, if the core is sapphire, then the cladding could be alumina-doped sapphire. In another example, the cladding material could be a polycrystalline form of the core material. Additionally, the cladding material includes a broadband absorber material such as alumina, graphene, a rare earth ion, a transitional metal ion or a p-block element. Thus, by matching the cladding material with the core material and then doping the cladding with a broadband absorber, its refractive index matches the core's index for all wavelengths and can suppress transverse oscillations across broad bandwidths.
The University of Central Florida invention describes various designs of self-centering thermogravimetric analysis (TGA) crucibles to allow samples to stay put at a constant location during the measurement process. Thermogravimetric analysis (TGA) measurements are carried out in dedicated systems where the mass of a sample is measured against that of a thermally stable standard. Various applications (for example, glass, ceramic or polymer processing) require precise and accurate TGA measurements to account for high-temperature modifications of materials, such as dehydration, decarboxylation or volatilization. When performed at high temperatures (approximately 2/3 melting point of materials), TGA measurements can exhibit uncontrolled variability on the order of a percent due to the motion of the sample in its crucible. This motion, caused by thermal decomposition or inhomogeneous sintering, displaces the center of mass of the sample with respect to the reference and destabilizes the balance during the measurement.
The University of Central Florida invention is a method for using a non-radioactive tracer to quantify the wear of a grinding medium while mechanically milling ceramic powders. The fabrication route of many materials, particularly glass and ceramics, requires the mixing of precursor powders followed by a ball milling process to ensure deagglomeration, intimate mixing, or satisfactory particle size. This invention relies on doping a commercially available grinding medium by high-temperature diffusion with species (for example, Cr3+, Eu3+, Fe3+) that can easily be quantified by modern analytical techniques. The total amount of tracer in the grinding medium after doping can be measured (in the form of a diffusion profile) via a surface-sensitive chemical analysis technique and provides a way to calculate the wear that each ball experienced.