PROCEEDINGS ARTICLE | February 7, 2012
Proc. SPIE. 8236, Laser Resonators, Microresonators, and Beam Control XIV
KEYWORDS: Microresonators, Optical spheres, Waveguides, Glasses, Luminescence, Ceramics, Ions, Coating, Sol-gels, Spherical lenses
Coating of spherical microresonators is a very promising technique for optimizing their optical
properties. Optical coatings are constituted by glasses, polymer, and glass ceramics, passive or
activated by luminescent species, Glass ceramic activated by rare earth ions are nanocomposite
systems that exhibit specific morphologic, structural and spectroscopic properties allowing to
develop interesting new physical concepts, for instance the mechanism related to the transparency,
as well as novel photonic devices based on the enhancement of the luminescence. At the state of art
the fabrication techniques based on bottom-up and top-down approaches appear to be viable
although a specific effort is required to achieve the necessary reliability and reproducibility of the
preparation protocols. In particular, the dependence of the final product on the specific parent glass
and on the employed synthesis still remain an important task of the research in material science.
Looking to application, the enhanced spectroscopic properties typical of glass ceramic in respect to
those of the amorphous structures constitute an important point for the development of integrated
optics devices, including coating of spherical microresonators. Here we present a review regarding
spherical microresonators coated by glass and glass-ceramic film activated by Er3+ ions. Er3+ ions
appear to be embedded in a crystalline or amorphous environment and the lifetime dynamic is
influenced by the geometry and by the morphology of the system. Photoluminescence results and
morphologic properties are discussed for both amorphous and glass ceramic films.
