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Focuses on a study which analyzed the nonmonotonic relation between the increasing wavelength and the noncritical phasematching temperature in a lithium triborate (LBO) crystal. Nonlinear optical characteristics and applications of LBO; Retrace in the second harmonic generation tuning curves; Beam walkoff and temperature acceptances in the vicinity of retracing positions; Conclusion.

Presents a study which discussed noncritical phase-matching (NCPM) properties for lithium triborate crystal. Measurement of second-harmonic generation with temperature-tuned phase matching; Comparison of the critical phase-matching temperature of the crystal with that of the NCPM temperature; Experimental conditions and results.

Provides information on a study investigating nonlinear optical materials on the basis of the anionic group theory. Methodology used to conduct the study; Information on anionic groups with no spontaneous polarization; Computer evaluation of microstructures by calculation of the C value; Findings of the study.

Focuses on a study which investigated general characteristics of dislocations in beta-barium metaborate bulk crystals via light-scattering tomography. Information on barium metaborate (BBO) materials; Benefits from a large birefringence contained in the material; Growth of BBO crystals; Cause of an optical loss due to light scattering.

Er3+:SrWO4 crystal of good optical quality was grown by Czochralski technique method. Polarized absorption and emission spectra of Er3+ ions in SrWO4 crystal have been investigated. The Judd-Ofelt (JO) theory was applied to the polarized absorption spectra of Er3+:SrWO4 to obtain the three JO parameters: Ω2=7.41×10-20 cm2, Ω4=0.25×10-20 cm2, and Ω6=1.71×10-20 cm2. The radiative probabilities, radiative lifetimes, and branch ratios of Er3+:SrWO4 were calculated. The stimulated emission cross sections of the potential laser transitions at 1535 nm were determined using the reciprocity method and the Fuchtbauer-Ladenberg formula, and the potential laser gain versus wavelength for the 4I13/2→4I15/2 transition has been estimated and discussed. [ABSTRACT FROM AUTHOR]

Presents information on a study which described the potassium fluoroboratoberyllate KBe[sub2]BO[sub3]F[sub2] as a novel ultraviolet nonlinear optical (NLO) crystal. Barrier to the development of NLO materials for the vacuum ultraviolet with second harmonic generation; Selection of anionic group; Conclusions.

Abstract: Single crystal Tm3+:SrMoO4 was grown successfully by Czochralski technique along the (001) orientation in N2 atmosphere. The refractive index of SrMoO4 crystal was measured at room temperature. The linear thermal expansion coefficients along c- and a-axes were measured to be 1.70×10−5 °C−1 and 0.59×10−5 °C−1, respectively. Its polarized absorption spectra, fluorescence spectra and fluorescence decay curve have also been investigated at room temperature. Based on the Judd–Ofelt theory, the intensity parameters have been determined as: Ω 2 =7.875×10−20, Ω 4 =2.797×10−20 and Ω 6 =0.92×10−20 cm2. The radiative probabilities, radiative branching ratios, radiative lifetimes and stimulated emission cross sections of Tm3+ in SrMoO4 were obtained. The quantum efficiency of the 3 H 4 level is determined to be approximately 88.56% for this material. [Copyright &y& Elsevier]

Abstract: The polarized absorption and emission spectra have been measured for the Tm3+ doped NaY(MoO4)2 crystal and spectral parameters have been estimated from the absorption data based on the Judd–Ofelt theory. The effective intensity parameters (t =2, 4, 6) are 11.67×10−20, 2.21×10−20, 1.74×10−20 cm2, respectively. From the intensity parameters, the radiative transition probabilities, radiative lifetimes, branching ratios and the emission cross-section have been calculated. In comparison with other Tm3+ doped laser crystals, Tm3+:NaY(MoO4)2 crystal has potential as a promising laser crystal. [Copyright &y& Elsevier]

Abstract: Large crystals of pure and Y b3+ doped NaY (MoO4)2 have been grown using the Czochralski method. The major problem with these crystals is that they are black in colour, causeing total absorption in the visible range, this was resolved by annealing and the nature of the colour defect was discussed. Measurements such as DTA, thermal expansion in different crystallographic directions, and refractive index as a function of wavelength were investigated. The broad absorption band at about 980 nm and high value of the absorption cross-section are obtained for the Y b3+ doped crystal. The results show that Y b3+:NaY (MoO4)2 crystal has potential as a promising laser crystal. [Copyright &y& Elsevier]

Abstract: The Dy3+-doped NaY(MoO4)2 single crystals were grown successfully by the Czochralski technique. The main spectroscopic properties (absorption, luminescence, decay curve) of Dy3+-doped NaY(MoO4)2 have been determined for both the σ and π polarizations. By using the Judd–Ofelt theory, the measured room temperature absorption spectra were applied to determine the intensity parameters, spontaneous transition probabilities, branching ratios, and radiative lifetimes of Dy3+ transitions. The results show that the Dy3+-doped NaY(MoO4)2 crystal may realize the yellow laser operation. [Copyright &y& Elsevier]

Abstract: Yb3+ doped SrWO4 crystal has been grown by the Czochralski method. Polarized absorption and emission spectra together with fluorescent decay curve were measured at room temperature. The stimulated emission cross sections of the potential laser transitions were determined using the reciprocity method and the Fuchtbauer–Ladenberg formula. The potential laser gain versus wavelength for the 2F5/2 → 2F7/2 transition was also estimated and discussed. This material is a potential candidate for a 1.0μm laser media. [Copyright &y& Elsevier]

Abstract: Tm doped NaBi(WO4)2 of good optical quality with sizes of about 20mm×20mm×40mm was grown successfully by the Czochralski technique. The absorption spectra for both σ- and π-polarizations were recorded at room temperature. Based upon these data, the oscillator strengths and radiative transition rates were evaluated. The σ- and π-polarized emission spectra together with the fluorescence decay curve were also obtained. The emission cross-section of the potential laser transition at 1460nm was determined to be 1.49×10−19 cm2. The results show that Tm3+:NaBi(WO4)2 crystal is a promising laser material. [Copyright &y& Elsevier]

Abstract: The polarized absorption, emission spectra and the fluorescence decay curve of Er3+ ions in the anisotropic NaY(MoO4)2 crystal were investigated at room temperature, and spectral parameters have been calculated from the absorption data based on the Judd–Ofelt theory. The experimental oscillator strengths for the transitions from the ground state to excited states were compared with the theoretical oscillator strengths calculated from the Judd–Ofelt theory. The emission cross-section and gain cross-section for the π- and σ-spectrum were determined for the 4H13/2 → 4H15/2 transition of special interest for laser application. [Copyright &y& Elsevier]

Abstract: Ca3Gd2(BO3)4:Er3+ crystals of high optical quality with a large size up to ∅25mm×60mm were grown by Czochralski method. The absorption spectra of the crystal in three mutually perpendicular arbitrary directions at room temperature were measured. Based on Judd–Ofelt theory and a least square fit of calculated three perpendicular directions and averaged results of the absorption line intensity (referred to as TPM method), the intensity parameters Ω t (t =2,4,6), the radiative transition rates, the radiative lifetimes, the fluorescence branching ratios, the experimental and theoretical oscillator strengths were obtained. The fluorescence spectrum and decay curve under the excitation of 530nm were presented too. The stimulated emission cross-section and radiative quantum efficiency were also diplayed. [Copyright &y& Elsevier]

Abstract: This paper reports the growth of Nd3+:NY(WO4)2 crystal with high optical quality and large size. Nd3+:NY(WO4)2 crystal with the dimension Φ30×75mm2 and optical homogeneity 4×10−5 was grown by Czhchoralski method: the seed used was [100] orientation, the pulling rate and rotating rate were 0.5–1.25mm/h and 15rpm, respectively. The growing processes and characteristics of Nd3+:NY(WO4)2 crystal was discussed. Its unpolarized absorption spectra and emission spectra were measured. The absorption cross-section and emission cross-section were presented. Based on the Judd–Ofelt theory, we obtained the three intensity parameters: , , and . The radiative probabilities, radiative lifetimes, branch ratios and quantum efficiency of Nd3+:NY(WO4)2 were calculated too. [Copyright &y& Elsevier]

Abstract: Dy3+: Ca3(BO3)2 crystal was grown successfully by the Czochraski technique. The absorption spectrum was measured and its absorption peaks were assigned. The Judd–Ofelt intensity parameters were found to be Ω 2=5.216×10−20, Ω 4=1.858×10−20, Ω 6=0.623×10−20 cm2. The spectroscopic parameters of this crystal such as the oscillator strengths, radiative transition probabilities, radiative lifetime as well as the branching ratios were calculated. Also, room temperature luminescence decay curve in correspondence with the emission line 4F9/2→6H13/2 centered at 575nm was measured. [Copyright &y& Elsevier]

Abstract: Large novel birefringent pure and rare earth-doped calcium borate crystals (Ca3(BO3)2) have been grown successfully by Czochralski technique. Thermal expansion coefficients of pure Ca3(BO3)2 have been obtained for the first time. Trivalent rare earth ions (RE3+), such as Dy3+- and Nd3+-doped calcium borate crystal, have been grown for optic application. Absorption and fluorescence spectra as well as fluorescence decay curves of Dy3+-, Nd3+-doped Ca3(BO3)2 crystals are measured at room temperature. Optical spectra show that there are obvious absorptions at ultraviolet to IR region. The strong emissions in visible and infrared region show that calcium borate is a suitable for rare earth-doped laser crystal. [Copyright &y& Elsevier]

Abstract: Tm3+:SrWO4 crystal of good optical quality with sizes of 15mm×60mm was grown successfully by Czochralski technique method. The orientation procedure of this crystal was discussed. The principal coefficients of thermal expansion along (001), (010), (100) directions were precisely measured to be 2.73×10−5, 1.00×10−5, 1.05×10−5 °C−1, respectively. Based on the Judd–Ofelt theory, we obtained the three intensity parameters: Ω 2=7.41×10−20, Ω 4=0.25×10−20, and Ω 6=1.71×10−20 cm2. The radiative probabilities, radiative life times, and branch ratios of Tm3+:SrWO4 were calculated. The room temperature polarized fluorescent spectra and fluorescent decay curve were measured. The luminescent quantum efficiency of the 3H4 level was investigated and the quantum efficiency is determined to be approximately 69.84% for this material. [Copyright &y& Elsevier]

Abstract: Pure and rare-earth (Nd3+, Tm3+ and Er3+)-doped strontium tungstates of good optical quality with sizes of about 20mm×50mm were grown successfully by the Czochralski technique. The (001) orientation was found to be the favorable direction for crystal growth. X-ray powder diffraction (XRD), differential thermal analysis (DTA) and differential scanning calorimeter (DSC) of pure strontium tungstate were measured. The concentrations of Nd3+, Tm3+ and Er3+ were measured and their segregation coefficients were also calculated. The absorption and emission spectra of rare-earth-doped crystals as a function of the and polarizations were presented and discussed. Favorable values of the absorption cross section centered at about 800nm suggest that Nd3+- and Tm3+-doped strontium tungstates are promising candidates for laser diode (LD) pumping. [Copyright &y& Elsevier]

Abstract: Nd3+ doped LaB3O6 single crystal with the size up to Φ20×35 mm was grown successfully by the Czochralski technique. The absorption and luminescence spectra of trivalent neodymium in LaB3O6 crystal were measured at room temperature. Also, room temperature luminescence decay curve in correspondence with the emission line 4F3/2→4I11/2 centered at 1062 nm was measured. In the framework of the Judd–Ofelt (J–O) theory, the intensity parameters were calculated to be: Ω2=0.54×10−20 cm2, Ω4=2.31×10−20 cm2, Ω6=6.94× 10−20 cm2. The calculated radiative probabilities, radiative branching ratios and radiative lifetime for the emissions from the 4F3/2 level of Nd3+ ions in LaB3O6 single crystal were presented. The luminescent quantum efficiency was also displayed. [Copyright &y& Elsevier]

The absorption and fluorescence spectra of Nd3+:Gd0.2Y0.766Al3(BO3)4 crystal have been measured. Basing on Judd–Ofelt and TPM theory, intensity parameters Ωt (t=2,4,6), radiative lifetime, experimental and theory oscillation strength, fluorescence branching ratios and stimulated emission cross-sections were obtained and related to the laser action of this crystal. A laser output of 48 mW at 1060 nm and of 78 mW at 1300 nm with the optical to optical efficiency of 20% and of 9.75% respectively were obtained under a Ti–sapphire laser pumping. Meanwhile, a laser output of 26.7 mW at 532 nm with an optical to optical efficiency of 10.68% was obtained when it was pumped by a AlGaAs diode laser. [Copyright &y& Elsevier]

Nd3+:LaB3O6 crystals with the size up to ∅20 mm×35 mm were grown by the Czochralski technique. The absorption spectrum was measured and its absorption peaks were assigned. The absorption cross section σa at about 799 nm was measured to be 3.37×10-20 cm2. An emission spectrum was obtained from 799 nm wavelength pumping. [Copyright &y& Elsevier]

The Ca3Gd2(BO3)4:Yb3+ crystal with a size up to ∅ 20 mm×50 mm was grown by the Czochralski method. The absorption and emission spectra were measured. There is a broad absorption band ranging from 850 to 1000 nm in the absorption spectrum. A broad emission spectrum from 930 to 1100 nm was exhibited from 895 nm wavelength pumping. This crystal is promising as a tunable infrared laser crystal. [Copyright &y& Elsevier]

The GdAl3(BO3)4:Tm3+ crystal with size up to 15 mm×15 mm×25 mm was grown from the K2O3–MoO3–B2O3 solvent system by the top seed solution growth (TSSG) method. The absorption spectrum was measured and its absorption peaks were assigned. The emission spectrum ranging from 500 to 1800 nm was obtained from 468 nm wavelength pumping. The absorption cross section σa at 800 nm was determined. [Copyright &y& Elsevier]

Pure and Nd3+-doped Cd3Y(BO3)3 crystals with sizes up to 20 mm were grown from a Li6B4O9 solvent system by using the top seeded solution growth method. The second harmonic generation coefficients of the crystals were measured to be about two times larger than that of KH2PO4 (KDP). The Absorption spectra were measured and the absorption peaks were assigned. The emission spectrum of Nd3+:Cd3Y(BO3)3 crystal was obtained under an excitation of 808 nm. [Copyright &y& Elsevier]

The Ca3Y2(BO3)4:Er3+ crystal with a size up to ϕ 20 mm×30 mm was grown by the Czochralski method. The absorption spectrum was measured and its absorption peaks were assigned to the corresponding transitions between the Er3+ energy levels. A broad emission spectrum from 1429.4 to 1662.8 nm was exhibited from 530 nm wavelength pumping. This crystal is promising as a tunable infrared laser crystal. [Copyright &y& Elsevier]

The absorption spectra of Tm3+:KGd(WO4)2 crystal in three mutually perpendicular arbitrary directions at room temperature were measured. Based on Judd–Ofelt theory and TPM method, the intensity parameters Ωt (t=2,4,6), the radiative lifetimes, the experimental and theoretical oscillation strengths, and the fluorescence branching ratios were obtained. The broad emission spectrum from 1650 to 2000 nm was obtained under 800 nm excitation. Also, the fluorescence spectra at 455 and 665 nm were measured under 360 nm excitation. Their stimulated emission cross-sections were also calculated. [Copyright &y& Elsevier]

The Tm3+:KGd (WO4)2 crystal with the size up to 50 mm was grown from the K2O–WO3–BO3 solvent system by using the top seeded solution growth method. The absorption spectrum was measured and its absorption peaks were confirmed. The emission spectra of the crystal at 455 and 665 nm were obtained when a light of 360 nm excited this crystal. A broad emission spectrum from 1650 to 2000 nm was obtained when a light of 800 nm excited this crystal. It is expected that this crystal may be useful as a tunable infrared laser crystal. [Copyright &y& Elsevier]

The Ca3Y2(BO3)4:Tm3+ crystal with the size up to ∅ 15 mm×35 mm was grown by the Czochralsky method. The absorption spectrum was measured and its absorption peaks were assigned to the corresponding transitions between the Tm3+ energy levels. A broad emission spectrum ranging from 1332.6 to 1429.1 nm was exhibited from 800 nm wavelength pumping. This crystal is promising as a tunable infrared laser crystal. [Copyright &y& Elsevier]

We demonstrate the simultaneous generation of the three basal red–green–blue colors from a lone GdAl[sub 3](BO[sub 3])[sub 4]:Nd[sup 3+] bi-functional laser and optical nonlinear crystal. The laser works in a dual-wavelength operation in the two [sup 4]F[sub 3/2]→[sup 4]I[sub 11/2] (near 1062 nm) and [sup 4]F[sub 3/2]→[sup 4]I[sub 13/2] (near 1338 nm) channels, under a fixed wavelength pumping (at 744.7 nm) and with a fixed crystal orientation. Red and green results from self-frequency doubling of the two laser channels, blue results of self-sum frequency mixing of the pump and the 1338 nm laser. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]