Materials World Network: Infrared Glass and Glass-Ceramics with New Optical and Mechanical Functionalities.

University Of Arizona, Tucson AZ

Investigators

Abstract

An international research team of students and faculty in the Materials Science Department at the University of Arizona and the Chemistry Department at the University of Rennes, France, develops high-efficiency luminescent glass-ceramics by incorporating active rare-earth ions within a very low phonon nanocrystalline environment. Low phonon environments are known to strongly reduce electron-phonon coupling which results in high radiative-emission rates and high fluorescence intensity. Chalcogenide glass-ceramics systems offer the possibility of tuning the environment of active rare-earth ions by incorporating them into a range of heavy alkali-halide or metal-halide nanocrystalline environments. The project builds upon joint expertise in the US and France in the chemistry and thermodynamics of these systems to synthesize and characterize nano-composite materials with high-efficiency fluorescent properties. Another notable advantage of these glass-ceramic is the ability to optimize the optical properties while retaining the formability of the glassy matrix in order to produce fibers. Chalcogenide glass-ceramics posses an extensive transparency over the infrared domain which opens the way for many applications such as telecom amplifiers and mid-infrared laser sources. The chalcogenide glass matrix is then selected such as to offer optimal transparency in the range of rare-earth emission considered for specific applications in the near- and mid-infrared. This research has the potential to induce a leap forward in infrared photonic technology. High-efficiency luminescent materials open the possibility to develop miniature laser source for lab-on-chip applications or amplifiers for fiber-to-the-home telecom delivery. In particular, with the recent development of OH-free SiO2, the telecom band has opened up from 1.2 to 1.7 microns and consequently requires a wider range of rare-earth emission wavelengths than the conventional Er3+. However, most rare-earth emitters in that critical range such as Pr3+, Tm3+ and Dy3+ are highly inefficient in oxide glasses. Hence the development of low phonon matrixes for these ions will permit to widely improve the capacity of information-carrying telecommunication networks. In addition, this research effort is fully integrated with an international educational program designed to benefit PhD students. Graduates students perform course work and research activities alternately at both universities and obtain a double PhD diploma.