ABSTRACT

This chapter focuses on the design and modeling of microsphere lasers based on rare-earth-doped glass materials, for emission in the visible or in the near-and mid-infrared wavelength regions. It briefly reviews important industrial applications of glass microspheres and nanospheres, including the exploitation of their reflective properties in signals and road markings and their use as a lightweight filler in composite materials or for storage and slow release of pharmaceuticals. Laser oscillation and signal amplification has been obtained in a variety of rare-earth doped microspheres constructed by employing different host glasses such as silica, phosphate, tellurite and ZBLAN glasses. The design of amplifiers and lasers based on rare-earth-doped microspherical resonators require the electromagnetic mode analysis of both the fiber and the microsphere; the coupled mode theory; the ion population rate equation formalism. Glass microspheres or glass beads, having diameter in the range from micrometer to millimeter, constitute one of the simplest optical elements, capable of refracting and focusing light beams.