High-Purity Nanopowders for Laser Applications

We have successfully developed high-quality laser-grade yttrium aluminum garnet (YAG), and lutetium oxide (Lu2O3), using a novel combustion chemical vapor condensation (CCVC) technique based on a proprietary NanoSpray Combustion process. The purity of the nanopowders was >99%. Nanopowders with different dopants have been synthesized over a 10–200 nm size range, with low-cost, high-purity precursors that are viable for large-scale production. Great strides have also been made in developing highly dense (>99% theoretical density) polycrystalline Nd-doped YAG pellets using vacuum sintering and hot isostatic pressing (HIP). This method is an alternative to the Czochralski method for making single-crystal ceramic bodies, which has several disadvantages including high cost, size, shape restrictions, and limitations in Nd concentrations (∼1 at %). Nanomaterials also enable higher percentages of Nd to be incorporated into the YAG lattice which improves laser efficiency and >85% near IR transmission, thereby reducing scattering losses associated with larger grain-size polycrystalline materials.