The E3Σ1+ (63S1)←A3Π0+(53P1) transition in CdAr revisited: The spectrum and new analysis of the E3Σ1+ Rydberg state interatomic potential.

Revisited study of the E3Σ1+ (63S1)←A3Π0+(53P1) transition in CdAr using both theoretical and experimental approach is presented. Systematic detection of the E3Σ1+in,υ'←A3Π0+,υ″=6 transition frequencies with higher accuracy and spectrally narrower laser extended and improved analysis and simulation of the LIF excitation spectrum. More consistent characterization of the E3Σ1+in-Rydberg state inner well using inversed perturbation approach methodology was achieved. Free←bound transitions in the E3Σ1+in←A3Π0+,υ″=6 excitation were taken into account in the analysis and simulation of the recorded spectrum. The updated spectroscopic characterization of the A3Π0+ state was also revisited.

Broadband anti-Stokes white emission of Sr2CeO4 nanocrystals induced by laser irradiation.

The laser induced white emission (LIWE) from Sr2CeO4 nanocrystals upon irradiation with a focused IR laser beam was investigated. It was observed to be a threshold phenomenon with its intensity increasing exponentially with the excitation power density. This process was investigated under double laser beam simultaneous excitation in the UV range leading to Stokes emission in the visible range and in the IR range leading to anti-Stokes LIWE. With increasing LIWE intensity, the Stokes emission intensity strongly decreased. The LIWE is accompanied by efficient photocurrent generation depending on laser excitation density followed by multiphoton absorption and ionization processes. Photoimpedance measurements showed a sharp increase of the dielectric constant by several orders of magnitude in the Sr2CeO4 nanocrystals during the LIWE process demonstrating a metallic-like behaviour. The mechanisms of LIWE include multiphoton absorption and ionization that lead to the creation of a coupled pair of Ce3+ and Ce4+ ions that allow for the intervalence charge transfer (IVCT) emission transitions in the white light range. A strong decrease of absorption band intensity of Sr2CeO4 with increasing LIWE intensity confirms the creation of (Ce3+, Ce4+) pairs.

Pressure-induced phase transition in LiLuF4:Pr3+ investigated by an optical technique.

The luminescence and luminescence kinetics of LiLuF(4) doped with 1.5 at.% of Pr(3+) obtained at high hydrostatic pressure changing from ambient to 220 kbar applied in a diamond anvil cell are presented. It has been shown that pressure causes shift of the emission lines toward the red with rates of the order of single cm(-1) kbar(-1). The pressure-induced phase transition from tetragonal to fergusonite structure for pressure above 100 kbar was observed. The crystal field calculations performed showed that this phase transition reduces the point symmetry of the Pr(3+) site from the S(4) to the C(2) point group.

Potentials of the D¹0u⁺ (6¹S0) and F³1u(6³P2) electronic Rydberg states of Cd2 from ab initio calculations and laser-induced fluorescence excitation spectra.

The method of supersonic free-jet expansion beam combined with techniques of laser spectroscopy was used in an investigation of vibronic and isotopic structures in the D¹0(u)⁺ (6¹S0) and F³1(u)(6³P2) electronic energy Rydberg states of Cd2. Laser-induced fluorescence excitation spectra recorded using the D¹0(u)⁺ ← X¹0(g)⁺(5¹S0) and F³1(u) ← X¹0(g)⁺ transitions in the region of 206-218 nm provided spectroscopic characteristics of the excited states and allowed constructing of their intratomic potentials. Isotopic structures recorded in the (υ',υ'') bands of the D¹0(u)⁺ ← X¹0(g)⁺ transition were used in determination of the D¹0(u)⁺ state vibrational characteristics (ω'(e)x'(e), ω'(e)x'(e)) and υ' assignment. The ν(0,0) recorded directly in the F³1(u) ← X¹0(g)⁺ transition enabled determination of the bottom of the F³1(u) state potential well. Valence ab initio calculations of Cd2 interatomic potentials were performed with relativistic and spin-orbit effects taken into account. The experimental results were compared with results of the ab initio calculations. A free-jet expansion of Cd2 as a source of entangled atoms for a test of Bell's inequality was analyzed.

Theoretical prediction of A(3)0+ <-- X(1)0+ and B(3)1 <-- X(1)0+ spectra of the Zn-rare gas van der Waal's molecules.

Excitation spectra arising from A(3)0+ <-- X(1)0+ and B(3)1 <-- X(1)0+ electronic transitions in the Zn-rare gas (RG) van der Waal's molecules are calculated using the newly obtained ab initio potential curves for these species. The radial Schrödinger equation for nuclear motion was solved numerically with the calculated potentials to evaluate the corresponding vibrational levels and radial wavefunctions for the ground X(1)0+ and excited A(3)0+ and B(3)1 states of the Zn-RG complexes. The wavefunctions have been subsequently used in the calculation of the appropriate Franck-Condon factors to yield information on relative intensities of the vibrational bands produced by A(3)0+ <-- X(1)0+ and B(3)1 <-- X(1)0+ transitions.