Optical Properties and Laser Operation of Yb:Y3Sc2Al3O12 Crystal

Optical properties of Yb:Y(3)Sc(2)Al(3)O(12) crystal were investigated and compared with those from Yb YAG crystals Laser-diode pumped continuous-wave and passively Q-switched Yb Y(3)Sc(2)Al(3)O(12) lasers with Cr(4+) YAG crystal as saturable absorber has been demonstrated for the first tim

Optical properties of LaSr2Ga11O20 crystals containing Cr3+

The optical properties of trivalent chromium ions in LaSr2Ga11O20 crystals have been investigated by means of absorption, emission, excitation, and lifetime measurements for various temperatures of the sample. The data so obtained allow us to determine the values of the crystal-field parameters in the framework of the Tanabe-Sugano model for the transition-metal ion in insulating crystals and glasses. In particular, the relatively narrow emission lines indicate a high value of the crystal field. Polarized absorption and excitation measurements have allowed the assignment of the electric dipole character to the two lowest-energy transitions. From polarized excitation measurements it was possible to infer the Cr3+-ion site distortion visible in a splitting of the otherwise degenerate 4T1 level. Moreover, the effect of tempeature on the emission bands' intensities and lifetimes reveals the simultaneous presence of different competitive phenomena during the deexcitation of Cr3+ ion. © 1995 The American Physical Society

Optical properties of Cr3+-ions in LaSr2Ga11O20

The optical properties of Cr3+ ions in the disordered LaSr2Ga11O20 crystal have been investigated through absorption, emission, excitation spectra. Polarized excitation measurements allows us to evaluate the crystal field parameters and to infer the distortion of the octahedral site of Cr3+. In spite of the relatively low value of the crystal field (Dq/B = 2.26) obtained from optical data, the emission spectra are constituted by two narrow lines. This behavior, typical of strong field material, is explained by an even lower value of the crystal field corresponding to the 2E, 4T2 crossing point obtained by means of the Tanabe-Sugano diagram. The value of the splitting and the width of the emission lines, intermediate between crystals and glasses, confirm the disordered structure of this crystal

Optical spectroscopy of La3Ga5SiO14:Cr3+ crystals

The optical properties of trivalent chromium ions in La3Ga5SiO14 crystals have been investigated by means of absorption, emission, excitation, and lifetime measurements. The particular intermediate value of the octahedral crystal field Dq/B∼2.5 causes the overlapping of the 4T2 with the 2E and 2T1 levels. This overlap is the origin of Fano resonances in the absorption spectrum and of the simultaneous presence of broadband and narrow-line emissions. Polarized measurements have allowed the determinations of second-order effects such as the tetragonal or orthorhomic distortion of the octahedron of oxygen ions around the chromium ion. Moreover the temperature shift of the peak and the nonexponential decay of the broad emission band are indications of the disorder present in the crystal lattice. All these results produce a fairly complete picture of the energy levels of Cr3+ ions in a typical crystal of the Ca-gallogermanate family. © 1994 The American Physical Society

Optical absorption spectroscopy of Nd3+ in the Ca3Ga2Ge3O12 laser garnet crystal

A systematic investigation of the optical absorption of the Nd3+ ion in the Ca3Ga2Ge3O12:Nd3+ garnet (CCGG:Nd) crystal is presented. An assignment of the Stark energy levels was carried out assuming a D-2 symmetry site for the Nd3+ ions in CGGG:Nd, Some relevant spectroscopy parameters for laser applications: radiative lifetime, branching ratios and quantum efficiency from the F-4(3/2) emitting state were estimated using the Judd-Ofelt theory. (C) 1999 Elsevier Science B.V. All rights reserved