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Optically active materials are used in many biomedical applications ranging from medical imaging to light therapies. Investigating the effects of differing nanostructure configurations on the optical performance of these materials can improve tunability, efficiency, and practicality for their respective applications. This work utilizes pulsed laser deposition (PLD) to develop nanostructured thin films and determines their optical performance for applications in computed radiography for medical imaging and in LEDs which can be used in biomedical applications such as photobiomodulation. In computed radiography, scattering of the stimulation light by the storage phosphor crystal grain boundaries in imaging plates negatively impacts spatial resolution. Storage phosphor plates with thinner phosphor layers have been developed to reduce scattering distance and increase spatial resolution, although at the expense of reduced x-ray absorption. A transparent or translucent nanostructured film, containing a much higher percentage of storage phosphor crystals achievable in bulk glass-ceramic materials made by conventional methods, may have acceptable photostimulated luminescence efficiency and imaging performance characteristics greater than commercial imaging plates. In an attempt to achieve a nanostructured film with superior performance in x-ray imaging, a glass-ceramic imaging plate for computed radiography was synthesized via PLD for the first time. The imaging plate was comprised of Eu-doped BaCl2 crystallites and an amorphous matrix. Nanolayered films comprising of BaF2, Eu2O3, and Al2O3 were synthesized via PLD with differing layered configurations to manipulate the coordinate surrounds of the europium dopant and determine its effects on optical properties. TEM cross-section analysis was conducted to verify the desired nano-layering. Different post-deposition heat treatments were investigated, and the films were evaluated for applications as a phosphor layer for UV-pumped white light LEDs which can be used for solid-state lighting and biomedical light therapies. A Mn dopant was added to europium to discover the threshold for the amount of manganese necessary to optically influence the nanolayered films. Although Mn/Eu co-doping did not prove advantageous for white light LEDs, all nanostructures of Eu-doped films have the potential for the desired application. Nanoscale control of optically-active thin films was demonstrated using pulsed laser deposition. Determining the effects of differing nanostructures on optical properties can lead to improvements in certain biomedical applications.

Digital radiography (DR) is an important two-dimensional imaging technique in the field of medicine that utilizes x-rays to form a digital image. DR employs a flat panel detector that converts incident x-rays, that have passed through the subject, to an electrical signal, which is used to create a digital image. The conversion from x-rays to electrical signals can be done either directly or indirectly. The direct method involves the x-rays being converted to an electrical signal via an array of semiconductors. The indirect method utilizes scintillators to absorb the x-rays and produce light in the visible spectrum, which is then collected by photodiodes and converted to an electrical signal. One issue that many modern flat panel detectors have is reduced efficiency due to a significant percentage of the incident x-rays passing through the detector without being absorbed. In order to raise the efficiency of these flat panel detectors, rare earth-doped scintillating glass ceramics have been proposed to replace the traditional non-scintillating borosilicate substrates that support the detector electronics. Two series of glass-ceramic scintillators were investigated for this purpose. The first series investigated the potential of calcium fluoride as a scattering center, as well as how the calcium fluoride luminescence behaved when doped with europium. The second series investigated the use of cerium as a sensitizer to improve the scintillating efficiency of terbium. Both series showed that the scattering and luminescent properties of the materials can be controlled. Scintillating glass ceramic materials have the potential to become viable replacements for the un-doped borosilicate substrates that are used in modern flat panel detectors.