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The crystal growth, polarized spectral properties, Judd-Ofelt (JO) analysis and lifetime of Sm:CaGdAlO 4 (Sm:CGA) crystal were reported for the first time. Sm:CGA crystal with size of Φ4 × 33 mm 3 was grown by the floating zone (FZ) method. The peak absorption cross-sections at 407 nm were calculated to be 3.41 × 10 −20 cm 2 and 3.20 × 10 −20 cm 2 for the σ and π polarization, and the largest stimulated emission cross-sections at 601 nm were 5.10 × 10 −21 cm 2 and 4.66 × 10 −21 cm 2 , respectively. The absorption and emission cross-sections were several times larger than that of Sm:LiYF 4 . The JO intensity parameters of Ω 2 , Ω 4 and Ω 6 were calculated to be 3.0 × 10 −20 cm 2 , 6.1 × 10 −20 cm 2 and 6.5 × 10 −20 cm 2 , respectively. The lifetime of the 4 G 5/2 level was obtained to be 0.69 ms. All the results indicate that Sm:CGA crystal is a potential laser host for the reddish-orange laser operation. [ABSTRACT FROM AUTHOR]

The crystal growth, optical spectra and lifetime of Dy:CaGdAlO 4 crystal were investigated for the first time to our best knowledge. Single Dy:CaGdAlO 4 crystal with size of Φ4 × 40 mm 3 was grown by floating zone method. The peak absorption cross-sections were calculated to be 2.43 × 10 −21 cm 2 and 1.28 × 10 −21 cm 2 at 453 nm for σ and π polarizations. The Judd-Ofelt (JO) parameters of Ω 2 , Ω 4 and Ω 6 were calculated to be 1.8 × 10 −20 cm 2 , 1.0 × 10 −20 cm 2 and 0.5 × 10 −20 cm 2 , respectively. The emission cross-sections were calculated to be 0.51 × 10 −20 cm 2 and 0.55 × 10 −20 cm 2 for σ and π polarizations. The fluorescence decay time is 222 μs. The results indicate that the Dy:CaGdAlO 4 crystal is a potential candidate for yellow laser operation. [ABSTRACT FROM AUTHOR]

The growth, XRD patterns, spectral properties, and fluorescence decays of Yb:Ca 0.28 Ba 0.72 Nb 2 O 6 (Yb:CBN) with doping concentration of 1 at.% and 5 at.% were studied. The peak absorption cross-section and the emission cross-section were calculated. Larger Stark splitting of Yb:CBN offers the prospect of the quasi-four level laser operation. The fluorescence lifetimes are 0.64 and 0.73 ms for 1 at.% and 5 at.%, respectively. The FWHM of absorption and fluorescence spectra of 5 at.% Yb:CBN are 62 and 68 nm, which are broader than other ultrashort laser media. The results prove that Yb:CBN crystal is a good candidate as an ultrashort laser medium. [ABSTRACT FROM AUTHOR]

Highlights: [•] Spectroscopic properties and crystal growth of Tm:LYSO single crystal were studied for the first time. [•] The large absorption and emission cross-section and broad FWHM make Tm:LYSO a promising media for tunable and ultrashort pulses. [•] The J–O parameters and gain spectra reveal that the excellent properties for laser applications. [Copyright &y& Elsevier]

Abstract: Pr3+, Yb3+ co-doped CaYAlO4 (Pr, Yb: CYA) single crystal was grown using the Czochralski (CZ) method. For near-infrared quantum-cutting system, a quantum efficiency of 145% for Pr3+, Yb3+-codoped CYA crystal has been obtained by ignoring the nonradiative losses. Under excitation at 940nm, high intensities of 502nm, 555nm, 628nm, 661nm and 729nm emissions turn up. Fluorescence decay time of 3P0→3F2 emission of Pr3+ ions and 2F5/2→2F7/2 transition of Yb3+ ions were also studied as evidences for energy transfer. [Copyright &y& Elsevier]

Abstract: Sm:CaNb2O6 single crystal has been grown by the Czochralski method. Its high-temperature X-ray powder diffraction, optical absorption, emission spectroscopic as well as lifetime have been studied. Thermal expansion coefficients (α), J–O parameters (Ω i ), radiative lifetime (τ rad), branching ratios (β) and stimulated emission cross-sections (σ e) were calculated. The quantum efficiency (η) was calculated to be 97%. The intense peak emission cross section at 610, 658nm were calculated to be 2.40×10−21, 2.42×10−21 cm2. These results indicate that Sm:CaNb2O6 crystal has potential use in visible laser and photonic devices area. [Copyright &y& Elsevier]

Abstract: Crystals of Ce3+-doped (Lu x Y1−x )3Al5O12 (LuYAG) have been grown and studied by X-ray powder diffraction, emission spectroscopy, excitation spectroscopy and X-ray excited fluorescence spectroscopy. The X-ray powder diffraction pattern revealed that the as-grown LuYAG:Ce crystal possessed the garnet structure. Compared with Ce3+-doped Y3Al5O12 (YAG), the absorption bands associated with the 4f–5d transition shifted to shorter wavelengths, the emission band that originated from a transition from the lowest 5d level to the 2F ground state of the Ce3+ ions shifted to the blue, which was probably due to a larger Stokes shift of the emission, and the reduction of relative intensity of antisite defect emission in the X-ray excited fluorescence spectra revealed that introducing Lu ions into YAG could reduce the antisite defect. [Copyright &y& Elsevier]

Abstract: Yb3+-doped (Lu0.5Y0.5)3Al5O12 (Yb:LuYAG) single crystal has been grown by the Czochralski method. The segregation coefficient of Yb3+ was studied by the inductively coupled plasma atomic emission spectrometry (ICP-AES) method. The crystal structure has been determined by X-ray diffraction analysis. The absorption and emission spectra and fluorescence lifetime of Yb:LuYAG crystal were measured at room temperature. The spectroscopic parameters of Yb:LuYAG crystal were compared with those of Yb:YAG and Yb:LuAG crystals with the same doping level. The results indicate that Yb:LuYAG crystals are potential candidates for high-power ultrashort pulse lasers. [ABSTRACT FROM AUTHOR]

Abstract: A Yb3+-doped CaYAlO4 laser crystal has been grown by the Czochralski technique. The segregation coefficient was measured by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The cell parameters were analyzed with X-ray diffraction experiments. Color defects in Yb:CaYAlO4 have been evidenced to be similar to those in undoped CaYAlO4. The polarized absorption spectra and the fluorescence spectrum of the Yb:CaYAlO4 crystal were measured at room temperature. The fluorescence decay time of the Yb3+ ion was investigated. The results show that Yb:CaYAlO4 has potential as a laser gain medium for an ultrashort laser system. [Copyright &y& Elsevier]

Abstract: The YAG crystal codoped with Yb3+ and Tm3+ has been grown by Czochralski (Cz) method. The crystal structure of the crystal has been determined by X-ray diffraction analysis. The absorption and emission spectra of Yb,Tm:YAG crystal at room temperature have also been studied. The emission cross-sections have been calculated by Fuechtbauer-Ladenburg formula and reciprocity method. [Copyright &y& Elsevier]

Abstract: Sheaf-like CuO consisting of nanoplatelets were synthesized by a hydrothermal method at 100 °C from Cu(NO3)2·3H2O and NaOH in the presence of an ionic liquid 1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM]BF4). The XRD indicated the high crystal quality of CuO with monoclinic crystal structure. FESEM and TEM images showed the nanoplatelets with lengths of 4–5 μm, thickness of 65–80 nm and end angle of 60°. FTIR spectra and TG/DSC curves confirmed the adsorption of [BMIM]BF4 on the surface of CuO. The morphology of CuO could be controlled by the feeding manner of [BMIM]BF4. It was demonstrated that [BMIM]BF4 served as a cosolvent and modifiers in the reaction system. Further, the possible growth mechanism of the sheaf-like CuO was proposed. [Copyright &y& Elsevier]

The Czochralski crystal growth of 50 at.% Yb:YAG single crystal was reported. The absorption spectrum, emission spectrum and fluorescence lifetime of Yb:YAG crystal were measured at room temperature. The spectroscopic parameters of nominal 50 at.% Yb:YAG crystal were compared with that of Yb:YAG crystal with low doping level. The results indicate that Yb:YAG crystals with high doping level are potential candidates used for compact, efficient thin chip lasers. [Copyright &y& Elsevier]

The stoichiometric laser crystal Yb3Al5O12 has been grown by the Czochralski method. The structure of the YbAG crystal has been determined by X-ray diffraction analysis. The absorption and emission spectra of YbAG crystal at room temperature have also been studied. The absorption, emission cross-section and fluorescence lifetime have been estimated as 0.64×10−20, 1.96×10−20 cm2 and 270 μs, respectively. The spectroscopic parameters of Yb:YAG and YbAG crystal have been compared, and the results indicate that YbAG is a promising stoichiometric laser crystal. [Copyright &y& Elsevier]

Cr4+:Yb3Al5O12 (Cr4+:YbAG) single crystal of high quality has been grown by the Czochralski method. X-ray powder diffraction (XRPD) experiments showed that the Cr4+:YbAG crystal had the same structure as YAG (Y3Al5O12) crystal. The data of thermal expansion and specific heat of the crystal have been measured. The thermal expansion coefficient is α=8.63×10-6/K. The specific heat is 131.8 cal/mol·K at 320.5 K. The results show that Cr4+:YbAG crystal is a promising self-Q-switched laser crystal. [Copyright &y& Elsevier]

Yb:CaYAlO 4 (Yb:CALYO) shaped crystal fibers with different Yb3+ doping concentration were successfully grown by the micro-pulling-down (μ -PD) method. The effect of the Yb3+ concentration on the structure, absorption, emission and lifetime was systematically studied. The strongest absorption peaks of Yb:CALYO crystal fibers are located at 977 nm for σ and π polarization. The micro-photoluminescence indicate that Yb3+ ions in CALYO single crystal fiber grown by the μ -PD method distributed evenly across a cross-section. The emission cross-section of 5 at.% Yb:CALYO crystal fiber was calculated to be 0.86 × 10−20 and 1.08 × 10−20 cm2 at 983 nm for σ and π polarizations. Benefited from the disordered structrure of CaYAlO 4 crystal, the full width at half maximum (FWHM) at 978 nm was 68.9 nm and 80.9 nm, respectively. The fluorescence lifetime of 2F 5/2 energy level of Yb:CALYO crystal fibers with concentration of 0.5 at.%, 1 at.%, 2 at.% and 5 at.% was calculated to be 435 μs, 484 μs, 514 μs and 453 μs, respectively. The experimental results show that Yb:CALYO crystal fiber is a potential laser medium for ultrashort laser operation. • Yb:CaYAlO 4 shaped crystal fibers were grown by the micro-pulling down method. • The crystal structure, polarized spectra were investigated. • The effect of Yb3+ concentration on the spectroscopic properties was evaluated. [ABSTRACT FROM AUTHOR]

Abstract: A high optical quality erbium doped Lu2SiO5 single crystal has been grown by the Czochralski method. The distribution coefficient of Er3+ was measured to be ∼0.926. The absorption and emission spectra as well as the fluorescence decay curve of the excited state 4I13/2 were measured at room temperature. The spectroscopic parameters were calculated using the Judd–Ofelt theory, and the J–O parameters Ω 2 , Ω 4 and Ω 6 were found to be 4.451×10-20, 1.614×10-20 and 1.158×10-20 cm2, respectively. The room-temperature fluorescence lifetime of the Er3+ 4I13/2→4I15/2 transition was measured to be 7.74ms. The absorption and emission cross-section as well as the gain cross-section in the eye-safe regime of 1400–1700nm were also determined and discussed. [Copyright &y& Elsevier]

Abstract: In this paper, single crystal of ytterbium (Yb) doped Ca5(PO4)3F (FAP) has been grown along the c-axis by using the Czochralski method. The segregation coefficients of Yb3+ in the Yb:FAP crystal has been determined by ICP-AES method. The absorption spectrum, fluorescence spectrum and fluorescence lifetime of the Yb:FAP crystal has been also measured at room temperature. In the absorption spectra, there are two absorption bands at 904 and 982nm, respectively, which are suitable for InGaAs diode laser pumping. The absorption cross-section (σ abs) is 5.117×10−20 cm2 with an FWHM of 4nm at 982nm. The emission cross-section (σ em) is 3.678×10−20 cm2 at 1042nm. Favorable values of the absorption cross-section at about 982nm are promising candidates for laser diode (LD) pumping. [Copyright &y& Elsevier]

Abstract: A large and transparent Yb:FAP crystal with dimensions up to ∅30mm×85mm has been grown by the Czochralski method. The preparation of the raw material has been investigated. X-ray power diffraction studies of Yb:FAP crystal confirm that the as-grown crystal is isostructural with the FAP crystal. The crystalline quality has been studied using X-ray rocking curve analysis. The segregation coefficient of Yb3+ in the Yb:FAP crystal has been also determined. Linear thermal expansion coefficients in [001] and [100] directions have been measured in the 30–800°C temperature range. [Copyright &y& Elsevier]

Sm:YAlO 3 (Sm:YAP) crystal with size of Φ28 × 80 mm3 was grown by Czochralski (Cz) method. Polarized absorption spectra and fluorescence spectra of Sm:YAP crystal were discussed for the first time. The peak emission cross-sections were calculated to be 0.80 × 10−21 cm2 (604 nm for a-polarization), 1.82 × 10−21 cm2 (604 nm for b-polarization) and 1.63 × 10−21 cm2 (610 nm for c-polarization), respectively. The Judd-Ofelt (JO) intensity parameters were calculated to be Ω 2 = 2.59 × 10−20 cm2, Ω 4 = 1.78 × 10−20 cm2 and Ω 6 = 2.98 × 10−20 cm2, respectively. The decay lifetime of 4G 5/2 energy level was measured to be 2.51 ms. All above results indicate the Sm:YAP crystal may be a potential candidate of reddish-orange laser pumped directly by the GaN/InGaN laser diode. • Sm:YAlO 3 crystal was grown by Cz method. • Polarized optical spectra of Sm:YAlO 3 crystal were investigated. • The transitions of 4G 5/2 → 6H 7/2 have the highest branching ratio value, which is suitable for reddish-orange laser. [ABSTRACT FROM AUTHOR]

Abstract Nd3+-doped Bi 4 Ge 3 O 12 (Nd:BGO) single crystals have been successfully grown by the micro-pulling-down (μ-PD) method. The absorption spectra, fluorescence spectra and fluorescence decay curve have been measured at room temperature. The absorption cross section is about 1.39 × 10–20 cm2 at around 808 nm for 0.3 at% Nd:BGO. The Judd–Ofelt theory has been applied to calculate the intensity parameters, and three spectroscopic parameter Ω t (t = 2,4,6), radiative transition probabilities, radiative lifetime and branching ratios were calculated. The stimulated emission cross-section of 4F 3/2 →4I 11/2 transition at 1064 nm was obtained to be 3.29 × 10–20 cm2 for 0.3 at% Nd3+-doped BGO crystal. The fluorescence lifetimes of 0.3 at% and 1.0 at% neodymium-doped BGO crystals were measured to be 288 μs and 242 μs, respectively. Those results indicate that Nd3+-doped BGO crystal grown by the μ-PD method would be a potential laser medium. [ABSTRACT FROM AUTHOR]

In this paper, the Floating zone technique was used to grow high-quality Cr3+:YScO 3 crystals. The absorption cross-sections of the 4A 2 →4T 1 transition and 4A 2 →4T 2 transitions were calculated to be 1.71 × 10−20 cm2 at 488 nm and 0.72 × 10−20 cm2 at 666 nm, respectively. The crystal field strength Dq, Racah parameters B, and C were calculated to be 1502 cm−1, 533 cm−1, and 3362 cm−1, respectively. In the Cr3+:YScO 3 crystal, the effective phonon energy and Huang-Rhys factor S were calculated to be 284 cm−1 and 8.62, respectively. The emission cross-section at 988 nm corresponding to the 4T 2 →4A 2 transition was calculated to be 1.44 × 10−20 cm2 with full width at half maximum (FWHM) of 318 nm. All the results show that Cr3+:YScO 3 crystal has the potential to be a tunable and ultrafast laser crystal. • Cr:YScO 3 crystals were successfully grown by the Floating zone technique(FZ) method. • Broad emission spectrum with full width at half maximum (FWHM) of 318 nm in Cr:YScO 3 crystals was observed. • Spectral properties and crystal field parameters of Cr:YScO 3 crystals were investigated and analysed. [ABSTRACT FROM AUTHOR]

Tb 3+ -doped YAlO 3 (YAP) single crystal was grown by Czochralski (Cz) method. Based on the polarized absorption spectra, the spectroscopic parameters were calculated to be Ω 2 = 3.49 × 10 −20 cm 2 , Ω 4 = 5.87 × 10 −20 cm 2 and Ω 6 = 2.55 × 10 −20 cm 2 , and then the spontaneous transition rate, fluorescent branching ratio and radiative lifetime of 5 D 4 multiplet were obtained. The yellow emission cross sections of 5 D 4 → 7 F 4 transition were calculated to be 1.72 × 10 −22 cm 2 , 2.73 × 10 −22 cm 2 and 2.65 × 10 −22 cm 2 for a, b and c polarization, respectively. The fluorescence lifetime of the 5 D 4 multiplet was fitted to be 1.72 ms. All the data indicate that Tb:YAP crystal is a promising candidate for yellow laser operation. [ABSTRACT FROM AUTHOR]

Tm-doped (Sc 0.5 Y 0.5 ) 2 SiO 5 (SYSO) crystals were grown by Czochralski method. The UV-VIR-NIR absorption spectra and the near-infrared emission spectra were measured and analysed by the Judd-Ofelt approach. Temperature influence on both absorption and emission spectra has been determined from the data recorded at room temperature and 10 K. It has been found that the structural disorder resulting from dissimilar ionic radii of Sc 3+ and Y 3+ in the solid solution (Sc 0.5 Y 0.5 ) 2 SiO 5 crystal brings about a strong inhomogeneous broadening of Tm 3+ ions spectra. However, it affects the excited state relaxation dynamics inherent to thulium-doped Y 2 SiO 5 and Sc 2 SiO 5 hosts weakly. [ABSTRACT FROM AUTHOR]

Pr 3+ -doped YAlO 3 (YAP) single crystal was successfully grown by the Czochralski (Cz) method. Polarized absorption and polarized fluorescence spectra were measured at the room temperature. The spectroscopic parameters based on the polarized absorption spectra were calculated by Judd-Ofelt (J-O) theory for the first time. The fluorescence lifetime of 3 P 0 energy level was fitted to be 19.16 μs with the quantum efficiency of 95.8%. Through the analyzing of the spectroscopic properties, Pr:YAP crystal was demonstrated to be a promising candidate for solid state laser operation. [ABSTRACT FROM AUTHOR]

High optical quality Dy:Y 3 Al 5 O 12 (Dy:YAG) crystal has been grown by the Czochralski method. Absorption spectra, fluorescence spectra and fluorescence decay curve of Dy:YAG have been recorded at room temperature. The strongest emission of Dy:YAG crystal is near 583 nm, corresponding to the 4 F 9/2 → 6 H 13/2 transition. The Judd-Ofelt parameters Ω 2 , Ω 4 and Ω 6 were calculated to be 1.49 × 10 −20 cm 2 , 0.94 × 10 −20 cm 2 and 3.20 × 10 −20 cm 2 , respectively. The radiative transition rates, branching ratios and the emission cross sections were calculated. The fluorescence and radiative lifetimes are 0.40 ms and 1.02 ms, respectively, resulting in a quantum efficiency of 39.2%. The results indicate that the Dy:YAG crystal would be a promising yellow solid state laser material. [ABSTRACT FROM AUTHOR]

Dy 3+ -doped YAlO 3 single crystal has been successfully grown by Czochralski technique. The spectroscopic parameters were determined by Judd-Ofelt theory based on the measured polarized absorption spectra. Dy:YAP crystal exhibits a yellow emission centered at 574 nm which can be used for pumping of the forbidden 1 S 0 - 3 P 0 ytterbium clock transition. The decay lifetime of the 4 F 9/2 level was measured to be 185 μs. [ABSTRACT FROM AUTHOR]

Ho3+-doped CaY 0.9 Gd 0.1 AlO 4 single crystal was successfully grown by the Czochralski technique for the first time. The polarized absorption spectra, polarized luminescence spectra and fluorescence decay curve of the crystal were investigated at room temperature. The spectroscopic parameters are calculated based on Judd–Ofelt theory, the values of Ω 2,4,6 were calculated to be 3.16 × 10−20 cm2, 3.93 × 10−20 cm2, 0.91 × 10−20 cm2, respectively. The Ho:CaY 0.9 Gd 0.1 AlO 4 crystal exhibits strong emission at 2013 nm for π- and 2032 nm for σ-polarizations with stimulated emission cross section of 6.64 × 10−20 cm2 and 1.90 × 10−20 cm2, respectively. The fluorescence lifetime of the 5I 7 level was measured to be 6.60 ms. The continuous-wave (CW) laser operation of Ho:CaY 0.9 Gd 0.1 AlO 4 crystal around 2 μm was demonstrated. • Ho3+-doped CaY 0.9 Gd 0.1 AlO 4 single crystal was successfully grown by the Czochralski technique for the first time. • The emission cross-section at 2013 nm and 2032 nm are 6.64 × 10−20 cm2 and 1.90 × 10−20 cm2 for π- and σ-polarizations respectively. • The continuous-wave (CW) laser operation of Ho:CaY 0.9 Gd 0.1 AlO 4 crystal around 2 μm was demonstrated. [ABSTRACT FROM AUTHOR]

Ho3+ and Eu3+ co-doping GdScO 3 crystal was successfully grown by special EFG method. The spectroscopic properties of the crystal were measured and analyzed. The absorption cross section was calculated to be 2.027 × 10−20 cm2 at 1161 nm. The J-O theory intensity parameters Ω t (t = 2, 4, 6), radiative transition rates, fluorescence branching ratios and radiative lifetimes were calculated. The Ho,Eu:GdScO 3 crystal has very strong emission at 2869 nm and the emission cross section was 13.524 × 10−21 cm2. The fluorescence lifetimes of the 5I 7 and 5I 6 levels were measured to be 4.457 ms and 1.265 ms. Confirmed that Eu3+ can be used as an effective deactivation ion of Ho3+ in GdScO 3 crystal. All those results show that the Ho,Eu:GdScO 3 crystal would be a potential laser material for ∼3 μm mid-infrared region. • Ho,Eu:GdScO 3 crystal was successfully grown. • The spectroscopic properties of the Ho,Eu:GdScO 3 crystal were analyzed. • J-O theory was applied to analyze fluorescence properties of the Ho,Eu:GdScO 3 crystal. • The energy transfer between Ho3+ and Eu3+ ions, spectroscopic characteristic of ∼3 μm emission were calculated and analyzed. [ABSTRACT FROM AUTHOR]

Ho:Lu 2 O 3 crystal was successfully grown by TGT method. The spectroscopic properties of the crystal were analyzed. The absorption cross section of Ho:Lu 2 O 3 were 0.307 × 10−20 cm2 at 1147 nm and 1.076 × 10−20 cm2 at 1929 nm. J-O theory was applied to analyze fluorescence properties of the Ho:Lu 2 O 3 crystal. The intensity parameters Ω t (t = 2,4,6), radiative transition rates, branching ratios and radiative lifetime were calculated. The Ho:Lu 2 O 3 crystal had very strong emission at 2027 nm and 2849 nm and emission cross sections were calculated to be 3.271 × 10−21 cm2 and 8.852 × 10−21 cm2, respectively. The fluorescence lifetimes of the Ho3+5I 7 and 5I 6 levels were measured to be 12.400 ms and 0.622 ms. All those results show that the Ho: Lu 2 O 3 crystal would be a potential laser material for mid-infrared region. • Ho: Lu 2 O 3 crystal was successfully grown by TGT method. • The spectroscopic properties of the Ho: Lu 2 O 3 crystal were analyzed. • J-O theory was applied to analyze fluorescence properties of the Ho:Lu 2 O 3 crystal. • The gain cross-section of Ho:Lu 2 O 3 crystal for ∼2 μm region and ∼3 μm region were calculated. [ABSTRACT FROM AUTHOR]

Abstract: Praseodymium and cerium co-doped yttrium silicate (Pr,Ce:YSO) crystal with high optical quality was grown by the Czochralski method. The segregation coefficient of Pr3+ and Ce3+ is measured to be 0.547 and 0.136, respectively. The polarized absorption bands centered at 268nm, 299nm and 356nm were assigned to 4f (2F5/2)→5d inter-configuration transitions of Ce3+, while bands centered at 220nm and 250nm were assigned to 4fn–4fn−15d transitions of Pr3+. The VUV–UV excitation spectra for monitoring Pr3+ emissions centered at 610nm (1D2→3H4) and 489nm (3P0→3H4), as well as Ce3+ emission centered at 450nm were recorded at T=8K in the range of 100nm–320nm. Polarized excitation spectra for Ce3+ emission centered at 424nm and Pr3+ emission centered at 611nm were recorded at T=300K. Polarized emission spectra were obtained upon excitation at 365nm and 456nm at T=300K. Lifetimes were estimated to be 170μs for Pr3+ (1D2), 3μs for Pr3+ (3P0) and 39ns for Ce3+ (5d1). [Copyright &y& Elsevier]

Highlights: [•] Ce doped Al2O3−YAG eutectic has been successfully grown by the Czochralski method. [•] The eutectic has a higher segregation coefficient of Ce3+ than YAG single crystal. [•] Photoluminescence properties of Ce-doped Al2O3–YAG eutectic were investigated. [•] Variouswhitecolourscouldbeobtainedasrequired,byvaryingtheeutecticphosphorthickness. [•] The distinctive structure of eutectic made it have a better performance in LED than particle-dispersed system. [ABSTRACT FROM AUTHOR]

Abstract: Spectroscopic properties of lutetium aluminum garnet Lu3Al5O12 (LuAG) single crystal doped with 1at.% of Pr3+ were investigated. The crystal was grown by the Czochralski method. Optical absorption, emission, excitation spectra and luminescence decay curves were recorded for this system in 5–500K temperature range. Excitation spectra in VUV–UV range (150–330nm) were also measured exploiting synchrotron radiation. It has been found that among bands of luminescence related to the 3PJ, 1D2 → 3HJ, 3FJ transition of Pr3+ in the visible region the 3P0 → 3H4 one, occurring ca. 488nm, is the most prominent. Luminescence lifetimes for the 3P0,1 and 1D2 levels were estimated to be 13 and 200μs respectively (at room temperature). VUV-excited emission spectrum stretches over the whole visible region. It has been concluded that the material under study is a promising phosphor that can be efficiently pumped by broad absorption bands centered at 240 and 280nm. [Copyright &y& Elsevier]

Abstract: A laser crystal Er3+:YbVO4 has been grown by the Czochralski method with excellent quality. The rocking curve from the (004) diffraction plane of the as-grown Er3+:YbVO4 crystal was measured and the full-width at half-maximum value was found to be 19.80in. for the (004) face. The effective segregation coefficient of Er3+ was studied by X-ray fluorescence and the crystal structure was determined by means of X-ray diffraction analysis. The polarized absorption spectra and the fluorescence spectra of Er3+:YbVO4 were measured at room temperature. The spectral parameters were calculated based on the Judd–Ofelt theory, and the intensity parameters Ω 2, Ω 4 and Ω 6 are found to be 5.50×10−20, 1.96×10−20 and 2.34×10−20 cm2, respectively. The emission cross-section has been calculated by the Fuechtbauer–Ladenbury method. The spectroscopic parameters of Er3+:YbVO4 are compared with other typical laser hosts. [Copyright &y& Elsevier]

Ho3+-doped GdScO 3 crystal was successfully grown by the edge-defined film-fed growth (EFG) method. The spectroscopic properties of Ho:GdScO 3 crystal were investigated at room temperature. The peak absorption cross-sections were 0.33 × 10−20 cm2 and 1.24 × 10−20 cm2 at 1160 nm and 653 nm with full widths at half maximum of 171.7 nm and 11.5 nm. The peak emission cross-sections of 5I 7 →5I 8 and 5I 6 →5I 7 transitions for the crystal were 0.49 × 10−20 cm2 and 1.24 × 10−20 cm2, respectively. The fluorescence lifetimes of the 5I 6 and 5I 7 multiplets were measured to be 1.12 ms and 6.13 ms, respectively. The results show that Ho:GdScO 3 crystal is a very promising material for 3 μm laser operation. • Ho:GdScO 3 crystal was successfully grown by the edge-defined film-fed growth (EFG) method. • The structure parameters of Ho:GdScO 3 crystal were studied by X-ray diffraction (XRD). • Spectral properties and Judd-Ofelt parameters of Ho:GdScO 3 crystal were investigated and compared. [ABSTRACT FROM AUTHOR]

Abstract: For the first time, a high optical quality Yb3+-doped lutetium pyrosilicate laser crystal Lu2Si2O7 (LPS) was grown by the Czochralski (Cz) method. The segregation coefficient of ytterbium ion in Yb:LPS crystal detected by the inductively coupled plasma atomic emission spectrometer (ICP-AES) method is equal to 0.847. X-ray powder diffraction result confirms the C2/m phase monoclinic space group of the grown crystal and the peaks corresponding to different phases were indexed. The absorption and fluorescence spectra, as well as fluorescence decay lifetime of Yb3+ ion in LPS have been investigated. The absorption and fluorescence cross-sections of the transitions 2F7/2↔2F5/2 of Yb3+ ion in LPS crystal have been determined. The advantages of the Yb:LPS crystal including high crystal quality, quasi-four-level laser operating scheme, high absorption cross-sections (1.33×10−20 cm2) and particularly broad emission bandwidth (∼62nm) indicated that the Yb:LPS crystal seemed to be a promising candidate used as compact, efficient thin chip lasers when LD is pumped at 940 and 980nm due to its low-symmetry monoclinic structure and single crystallographic site. [Copyright &y& Elsevier]

GdScO 3 single crystal codoped with Tm3+ and Tb3+ ions was successfully grown by the Edge-defined Film-fed Growth Method (EFG) for the first time. Absorption, fluorescence spectrum and fluorescence lifetimes of the grown crystal at room temperature were measured. The absorption cross-section at 789 nm was calculated to be 8.20 × 10−21 cm2. The emission cross-section was 1.35 × 10−21 cm2 at 1504 nm with the FWHM of 95.3 nm. The fluorescence lifetimes of the 3H 4 state and the 3F 4 state were fitted to be 253 μs and 1460 μs, respectively. Compared with Tm3+ single doped GdScO 3 crystal, the codoping of Tb3+ successfully depopulated the 3F 4 energy level and enhanced the emission at 1.5 μm region. It indicated that Tm,Tb:GdScO 3 could be favorable laser medium for 1.5 μm-laser operation. • Tm3+ and Tb3+ co-doped GdScO 3 crystal was successfully grown by the edge-defined film-fed method (EFG) for the first time. • Spectral parameters and Judd-Ofelt parameters of Tm,Tb:GdScO3 crystal were obtained and compared. • The fluorescence mechanism of Tm3+ and Tb3+ co-doped GdScO 3 crystal has been studied. [ABSTRACT FROM AUTHOR]

Tm3+- doped GdScO 3 single crystal was successfully grown by the edge-defined film-fed method (EFG) for the first time. The spectroscopic properties of the crystal were investigated at room temperature. The absorption cross section of Tm:GdScO 3 at 795 nm is 1.58 × 10−20 cm2. By applying the Judd–Ofelt approach, the intensity parameters Ω 2,4,6 , radiative transition rates, branching ratios and radiative lifetime were calculated. Tm:GdScO 3 exhibits strong emission at 1460 nm and 2300 nm with stimulated emission cross section of 1.8 × 10−21 cm2 and 2.7 × 10−21 cm2, respectively. The fluorescence lifetime of the 3H 4 level was measured to be 265 μs. All the results indicated that the Tm:GdScO 3 crystal is a potential laser material. • Tm:GdScO 3 crystal was successfully grown by the edge-defined film-fed method (EFG) for the first time. • The structure parameters of Tm:GdScO 3 crystal were investigated by XRD. • Spectral parameters and Judd-Ofelt parameters of Tm:GdScO 3 crystal were obtained and compared. [ABSTRACT FROM AUTHOR]

LaMgAl 11 O 19 (LMA) crystal with nominal Sm3+ concentrations of 8 at.% was grown by the Czochralski method. Polarized absorption spectra, polarized emission spectra and fluorescence decay curve of Sm:LMA crystal were recorded at room temperature. The absorption cross-sections at 404 nm were calculated to be 2.33 × 10−20 cm2 and 0.86 × 10−20 cm2 for σ and π polarization, respectively. The spontaneous transition rates, branching ratios and the radiative lifetime of the 4G 5/2 multiplet, were calculated. The Judd-Ofelt theory has been applied to evaluate the Ω t (t = 2, 4, 6) intensity parameters. The highest stimulated emission cross-sections for the 4G 5/2 → 6H 7/2 transition around 594 nm were calculated to be 1.67 × 10−21 cm2 for σ polarization and 1.15 × 10−21 cm2 for π polarization, with full width at half maximum (FWHM) of 7.68 nm and 7.27 nm, respectively. The fluorescence lifetime of the 4G 5/2 manifold was 1.84 ms. All the results show that Sm:LMA crystal would be a promising orange-red solid state laser material. • The most intensive absorption line of Sm3+ ion, suitable for 405 nm InGaN laser diode. • The rigidity of Sm:LMA crystal is higher than some host crystals. • The value Ω 2 of Sm:LMA crystal is comparable to Sm:LiYF 4. • The large parameter σ em τ of Sm3+ in LMA is beneficial for the solid state laser. [ABSTRACT FROM AUTHOR]