Investigation of gas temperature measurements using ultraviolet excitation

A high resolution spectrographic study has been made of the nitrogen first negative system as induced by ultraviolet radiation. The radiation used in this experiment was the neutral helium resonance radiation at 584 A. Nitrogen molecules at approximately 300 K and at a pressure of one torr were ionized by the ultraviolet radiation with the aid of a windowless experimental configuration. The resulting nitrogen fluorescence was analyzed with sufficient resolution to enable study of the intensities of the R branch rotational lines of the 0-0 vibrational band of the first negative system. The data indicate that the induced population of the upper levels approximates a Boltzmann Distribution at the ambient temperature of the gas

Orange emission in Pr3+-doped fluoroindate glasses

We synthesize and study the properties of praseodymium doped fluoroindate glasses. Glass compositions with praseodymium molar concentrations up to 5% were obtained with good optical quality. Thermal, optical, and luminescence properties are investigated. Judd–Ofelt analysis is used to determine radiative lifetime and emission cross-section of the orange transition originating from the 3P0 level. We find that these glasses are good candidates for the realization of blue diode laser pumped orange lasers for quantum information processing applications

Spectroscopy of high-energy states of lanthanide ions

We discuss recent progress and future prospects for the analysis of the 4f${N-1}$5d excited states of lanthanide ions in host materials. Ab-initio calculations for Ce$^{3+}$ in LiYF$_4$ are used to estimate crystal-field and spin-orbit parameters for the 4f$^1$ and 5d$^1$ configurations. We discuss the possibility of using excited-state absorption to probe the electronic and geometric structure of the 4f$^{N-1}$5d excited states in more detail and we illustrate these ideas with calculations for Yb$^{2+}$ ions in SrCl$_2$

Sum Rules for Multi-Photon Spectroscopy of Ions in Finite Symmetry

Models describing one- and two-photon transitions for ions in crystalline environments are unified and extended to the case of parity-allowed and parity- forbidden p-photon transitions. The number of independent parameters for characterizing the polarization dependence is shown to depend on an ensemble of properties and rules which combine symmetry considerations and physical models.Comment: 16 pages, Tex fil

Aggregation of Rare Earth Coordination Complexes in Solution Studied by Paramagnetic and DOSY NMR

The degree of aggregation of neutral, 9‐coordinate rare earth coordination complexes has been shown to affect their ligand field, as revealed by diffusion‐ordered NMR spectroscopy (DOSY‐NMR) measurements on Y(III) complexes, paramagnetic NMR analyses of Yb and Tb analogues and emission spectral studies with the EuIII systems. In non‐polar media a lipophilic tris‐isopropyl complex, [Ln.L2] tends to aggregate in chloroform and dichloromethane giving rise to oligomers, whereas in acetic and trifluoroacetic acid the more polar parent complex, [Ln.L1], also aggregates, profoundly affecting the pseudocontact shift and the form of the Eu emission spectrum. Such behaviour has important implications in the design of responsive spectral probes

Spectroscopic characterization of CaNb2O6 single crystal doped with samarium ions

Spectroscopic measurements of the calcium niobate CaNb2O6 single crystal doped with samarium ions were performed. Polarized absorption and emission spectra as well as luminescence decay curves of this material were recorded as a function of temperature in the 5–300 K temperature region. Analysis of low temperature spectra made it possible to determine energies of crystal field components of Sm3+ multiplets involved in the excitation and luminescence phenomena. Number of crystal field levels derived implies that Sm3+ ions in the CaNb2O6 host are accommodated in several different sites. Radiative lifetime of the 4G5/2 metastable level determined based on the Judd–Ofelt analysis of room temperature absorption spectra amounts to 777 μs, a value close to that of luminescence lifetime determined from luminescence decay curve. Energy transfer between the NbO6 group and samarium ions was observed in wide temperature range. Intense luminescence related to the 4G5/2→6H7/2 and 4G5/2→6H9/2 transitions centered at 610 nm and 660 nm, respectively, combined with strong absorption band near 404 nm that matches perfectly the pump light provided by commercial InGaN/GaN diode lasers points at a potential of CaNb2O6:Sm3+ for the design of all-solid-state visible lasers