During Phase I, en-route to the development of eye-safe solid state ceramic lasers with enhanced thermal management capabilities, Photonics Innovations, Inc in collaboration with the University of Alabama at Birmingham will fabricate and characterize nano-scale powders of a wide bandgap semiconductors Er3+:GaN and Cr2+:ZnS. Micro-nano-scale powder doping with rare-earth Er or Cr ions will be performed either in situ during the powder synthesis process, via post-synthesis thermo-diffusion of dopants into the powder, or by laser ablation of doped crystals. Micro-nano-scale powders will be further reduced into nano-scale by means of mechanical grinding and laser ablation in liquid and gaseous environments. XRD, TEM, and near-field fluorescence imaging characterization will be performed to verify sub- micron size of the powders, uniform particle distribution, and low concentration of unwanted impurity. It will be followed by photo-luminescence (PL), PL kinetic spectroscopy, and gain-switched random lasing experiments overall demonstrating efficient near and mid-IR PL of developed powders. Technical pathways leading to further consolidation of the powders into transparent laser grade ceramic will be also formulated.
Keywords: Wide-Band Semiconductors, Nano-Scale Powders, Rare-Earth Ions, Transition Metal Ions, Random Powder Lasing, Ceramic Lasers