Influence of processing variables on the properties of polycrystalline YAG fibers

Abstract

Yttrium aluminum garnet (YAG) is a candidate host material for high power lasers, and the advantages of polycrystalline forms of YAG relative to single crystal (in terms of production cost, mechanical/optical properties, and feasible dopant concentrations) have been demonstrated. In addition, novel gain media in fiber form have attracted attention because of the potential for enhanced cooling efficiency, vibration resistance, and elimination of free space optics. Consequently, our work focuses on the development and characterization of optical-quality polycrystalline YAG fibers. Utilizing robust ceramic processes, we can readily produce highly transparent YAG fibers of ~30 μm diameter. We have recently begun characterizing both the mechanical properties and optical loss of these polycrystalline YAG fibers. In this report, the experimental setups for these measurements will be described and the effects of processing variables on the properties of polycrystalline YAG fibers will be discussed.