Trivalent zirconium and hafnium ions in yttria-based transparent ceramics
Electron paramagnetic resonance spectra of transparent yttria-based ceramics with zirconium and hafnium additives contain signals with close parameters due to paramagnetic Zr3+ and Hf3+ ions, which have similar ground-state electron configurations of [Kr]4d1 and [Xe]5d1, respectively.
Improved polycrystalline ceramic lasers
Improved polycrystalline ceramic laser rods, composed of cubic solid solutions of 89–96.5 mole% Y2O3, 10–2.5% ThO2, and 1% Nd2O3, were synthesized by a conventional sintering process. This material, called Nd‐doped Yttralox (NDY) ceramic, was produced with laser threshold energies lower than that of the best commercially available Nd:glass laser rod and with a lasing efficiency ∼94% that of laser glass at 40 J of input energy under pulsed mode conditions. In a similar operating mode a NDY rod, containing 5 mole% ThO2 and having dimensions 7.6×0.46 cm, delivered 0.41 J of optical energy when using an input energy of 162 J, a pump pulse of 150 μsec, and output mirror reflectivity of 70%. The lasing efficiencies depended strongly on the method of powder preparation and processing, composition, and the cooling rate from the sintering temperature. The dependence of the fluorescent linewidth on the NDY composition provides a means of appreciably varying the material gain coefficient. Active attenuation coeffici...
LASERS, ACTIVE MEDIA: Numerical simulation of a CO laser pumped by a medium-pressure combined discharge
A model of a pulsed CO laser pumped by a medium-pressure combined discharge at room temperature is discussed. The optimum parameters of the active medium (pressure, specific energy input, and the ratio E/p for different mixtures) at which the calculated efficiency for a mixture with the composition CO:He=1:3 amounts to 14% are calculated. The dependence of the output parameters on the additions of nitrogen and xenon to the working mixture is analysed.