Section Of Nd Research Articles

Proton and alpha particle induced L-shell ionization of rare earth and heavy eleme nts

The L-shell X-ray production cross sections of Ta, Au and Bi by proton and alpha particle projectiles and the L-subshell ionization cross sections of Nd, Dy and Ho bombarded by incident alpha particles are reported. Comparison of these results with ECPSSR calculations are also reported.

L- and M-shell x-ray production cross sections of Nd, Gd, Ho, Yb, Au, and Pb by 25-MeV carbon and 32-MeV oxygen ions.

Article discussing research on L- and M-shell x-ray production cross sections of Nd, Gd, Ho, Yb, Au, and Pb by 25-MeV carbon and 32-MeV oxygen ions.

L-subshell ionization of Nd, Gd, and Er by 0.40 to 2.00 MeV incident deuterons

Subshell X-ray production cross sections of Nd, Gd and Er were measured for incident deuterons with energies between 0.40 and 2.00 MeV. These measurements are compared to theoretical X-ray production cross sections (obtained from the theoretical ionization cross sections by the use of theoretical values of fluorescence yields and Coster-Kronig transition probabilities) predicted by the Plane Wave Bom Approximation and Perturbed Stationary State theories (including relativistic and Coulomb deflection effects). No one theory provides a best fit to the experimental data. However, there is a marked improvement in the fit as the Z of the target atom increases.

1.064- and 1.32-µm Nd:YAG single crystal fiber lasers

We report the development of CW 1.06- and 1.32-μm fiber lasers made of short sections of Nd:YAG single crystal fibers optically end-pumped either with an Argon-ion laser ( \lambda = 0.5145\mu m) or a single laser diode ( \lambda = 0.817\mu m). High conversion efficiencies, a few milliwatt thresholds and 10-20 mW output powers are reported, as well as a good coupling efficiency to a standard single-mode fiber. Loss mechanisms and means of reduction are also investigated for a variety of fiber lasers in either guided or unguided configurations.

Induced emission cross section of Nd:Y3Al5O12 grown by floating zone method

Optical spectra and emission lifetimes are measured for three Nd:Y3Al5O12 crystals grown by the floating zone method. The properties are almost the same as those of crystals grown by the conventional Czochralski method. The induced emission cross sections obtained for the three samples are 7.4, 5.3, and 7.0×10−19 cm2. These values are comparable to those reported so far.

Tailoring stimulated emission cross sections of Nd3+ laser glass: Observation of large cross sections for BiCl3 glasses

The stimulated emission cross sections of rare-earth transitions depend strongly on the host. The properties that influence the cross sections—line strength, linewidth, and refractive index—are reviewed, and rules for tailoring cross sections are discussed. To illustrate the application of these rules, the largest stimulated emission cross section for the 4F3/2→4I11/2 transition of Nd3+ observed for any oxide or halide glass was obtained for a new class of bismuth-chloride-based glasses. Spectroscopic and physical properties and laser parameters of these and other halide glasses are presented.

CW laser operation of Nd:YLF

CW laser operation of Nd:YLF is reported for the first time and, in a comparison to Nd:YAG, exhibits a lower threshold and higher single-mode average power. The TEM 00 mode volume of Nd: YLF was observed to be a factor of four larger than Nd:YAG, resulting in twice the TEM 00 mode average power. This result is attributed to the substantially lower thermal lensing of YLF with respect to YAG. In comparative measurements the stimulated emission cross section of Nd:YLF was found to be 1.8 \times 10^{-19} cm2for the π oscillation and 1.2 \times 10^{-19} cm2for the σ oscillation, as compared to 2.4 \times 10^{-19} cm2for Nd:YAG. The spectroscopic and lasing parameters of Nd:YLF indicate a potential for this material in high peak and average power Q -switched applications.

Stimulated emission cross sections of Nd:YVO4 and Nd:La2Be2O5 (BeL)

The stimulated emission cross sections σ of the 4F3/2→4I11/2 transitions have been measured for a-axis Nd:YVO4 (1064.1 nm, σ = 19.0×10−19 cm2), x-axis Nd:BeL (1079.2 nm, σ = 1.54×10−19 cm2), and y-axis Nd:BeL (1070.1 nm, σ = 2.31×10−19 cm2).

Laser emission cross section of Nd:YAG at 1064 nm

The stimulated emission cross section of Nd:YAG (yttrium aluminum garnet) (4F3/2→4I11/2) was compared to the known cross section of Nd:ED-2 glass at 1060 nm. Small samples of Nd:YAG and ED-2 glass were end pumped with a chopped cw 514.5-nm argon-ion laser in an identical geometrical arrangement. The stimulated emission cross section obtained for Nd:YAG at 1064 nm was found to be 7.6 ×10−19 cm.

Large stimulated emission cross section of Nd 3+ in chlorophosphate glass

We have investigated the spectroscopic properties of Nd 3+ in a series of sodium chlorophosphate glasses. Glasses with 30–40 mol.% ZnCl 2 have the largest stimulated emission cross section for the 4 F 3/2 → 4 I 11/2 transition we have measured for any glass. The large cross section in this mixed anion glass is attributed to a combination of a large line strength, narrow emission bandwidth, and favorable nephelauxetic shift.

Nd : Y2O3 single-crystal fiber laser: Room-temperature cw operation at 1.07- and 1.35-μm wavelength

Single-crystal fibers have been grown from high-purity 1.5 wt% Nd2O3 : Y2O3 powder mixtures, and short lengths of the fiber in dielectric mirror resonators have been evaluated as lasers at both 1.07- and 1.35-μm wavelength. The laser transition cross sections were approximately equal at the two wavelengths, and they were about two-thirds the cross section of Nd : YAG at 1.31 μm. The fluorescence lifetime of the laser samples was 340 μsec. Loss in the material was approximately 3% per cm. The absorption spectrum from 0.7 to 1.0 μm and fluorescence spectra for the 4F3/2→4I9/2, 4F3/2→4I11/2, and 4F3/2→4I13/2 manifolds of Nd3+ in Y2O3, taken with fiber samples, are reproduced in detail. The resultant energy levels are given. With a Kr laser operating at 0.7525 μm as the end pump, minimum observed laser threshold was 0.57 mW absorbed pump power for a 100-μm-diam 2.5-mm-long fiber operating cw in room-temperature air at 1.07 μm. The lasers operated in one or two transverse modes and had active linewidths of approximately 2 Å.