Search

We demonstrated an efficient and controllable dual-wavelength continuous-wave (CW) laser of Nd:Lu 2 SiO 5 (Nd:LSO) crystal. The maximum output power was 3.02 W at wavelength of 1075 nm and 1079 nm, and with increasing of absorbed pump power, the ratio of 1079 nm laser rose. The slope efficiency of 65.6% and optical-to-optical conversion efficiency of 63.3% were obtained. The passively Q-switched laser properties of Nd:LSO were investigated for the first time. The shortest pulse, maximum pulse energy and peak power were 11.58 ns, 29.05 μJ and 2.34 kW, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Yb:Y3Al5O12 (Yb:YAG) single crystals with Yb doping concentration 0.5at.%, 5at.%, 15at.%, 25at.%, 50at.%, 100at.% and Yb:YAlO3 (Yb:YAP) single crystals with Yb doping concentration 0.5at.%, 5at.%, 15at.%, 30at.% were grown by the Czochralski process. The fluorescence spectra of these crystals and the effects of self-absorption on the shape of the fluorescence spectra were studied. Through comparing the fluorescence spectra of Yb:YAG and Yb:YAP, all results indicate that the effects of self-absorption on the fluorescence spectra of Yb:YAP are remarkably stronger than that of Yb:YAG at the same Yb concentration. [Copyright &y& Elsevier]

Ho,Pr:CaYAlO 4 (Ho,Pr:CYA) crystal doped with 1 at.% Ho3+ and 0.1 at.% Pr3+ was successfully grown using the Czochralski method. Polarized absorption spectra, emission spectra, and fluorescence lifetime measurements were performed. The impact of Pr3+ co-doping on the ∼3 μm emission of Ho3+ ions was analyzed. The energy transfer efficiency from Ho3+:5I 7 to Pr3+:3F 2 energy level was calculated to be 60.66 %, indicating that Pr3+ effectively mitigated the self-termination effect in Ho,Pr:CYA crystals. The absorption cross-section at 645 nm was found to be 1.53 × 10−20 cm2 for σ polarization and 2.62 × 10−20 cm2 for π polarization. The emission cross-section at 2842 nm was calculated to be 0.86 × 10−20 cm2 for σ polarization and 1.33 × 10−20 cm2 for π polarization at 2908 nm, with a full width at half maximum (FWHM) of 139 nm and 88 nm, respectively. The fluorescence lifetimes of the 5I 6 and 5I 7 levels were measured to be 0.17 ms and 2.01 ms, respectively. These results collectively suggest that Ho,Pr:CYA crystals hold great potential as a candidate for 2.8 μm laser applications. • Ho3+,Pr3+ co-doped CaYAlO 4 crystal was grown by the Czochralski method. • The crystal structure, polarized absorption and emission spectra were investigated. • The intensity parameters were obtained using J-O theory. [ABSTRACT FROM AUTHOR]

Abstract: The Cr(0.1%),Yb(10%):GGG crystals have been grown by the Czochralski method. The chemical composition is: Yb0.33Gd2.47Cr0.005Ga5.2O12. There are no observed Yb3+ ions substituting Ga3+ ions, just like that of Yb:GGG crystals. The defects in Cr,Yb:GGG crystal were also investigated. The absorption and emission spectra of Cr,Yb:GGG crystal at room temperature have been measured. The O2 and H2 annealing effect of Cr,Yb:GGG crystal have been compared. Cr3+ can greatly weak the visible luminescence of this crystal. The Cr–Yb-codoped crystals may be potential materials for compact, efficient, high stability LD pumped solid state lasers. [Copyright &y& Elsevier]

Abstract We report on the growth, spectroscopic properties and visible laser operation of Pr3+-doped LaMgAl 11 O 19 (LMA) crystal. The absorption and emission spectra were recorded in visible wavelength range and the decay time of 3P 0 manifold was measured to be about 34.5 μs at room temperature. Using an InGaN laser diode as pump source, continuous-wave laser operation of Pr:LMA crystal have also been demonstrated in red at about 645 nm and deep red at about 725 nm, which provide new linearly polarized sources for various potential applications. Highlights • A Pr:LMA crystal was successfully gown by using the Czochralski method. • Spectral parameters of Pr:LMA crystal were obtained. • Using a blue laser diode as pump source, red and deep red laser were demonstrated from Pr:LMA crystal. [ABSTRACT FROM AUTHOR]

Ce,Tb,Gd:YAG-Al 2 O 3 eutectic crystal phosphor plates (ECPPs) were grown by the micro-pulling-down (μ-PD) method to adjust correlated color temperature (CCT) and color rendering index (Ra) for high-power warm white LED applications. Tb3+ and Gd3+ ions in Ce:YAG-Al 2 O 3 play a positive role in spectra adjustment based on the structural and luminescent properties investigations. Tb3+ ions enhance the fluorescence lifetime of Ce3+ ions from 61.1 to 63.8 ns and improve the luminescence efficiency, and the highest optical-optical conversion efficiency (OCE) is 270.56 lm/W. Corresponding luminescence shift from cold white to greenish yellow. Gd3+ ions increase the peak wavelength from 554 to 564 nm and improve the Ra value, and the maximum Ra is 75.5. Corresponding luminescence is shifted from cold white to reddish violet. In addition, the luminescence of Ce,Tb,Gd:YAG-Al 2 O 3 ECPPs is adjusted to warm white with CIE coordinate (0.374, 0.364) and CCT of 4102 K, and Ra of 73.0, which is of great significance for realizing the high-power warm white LED lighting. • Tb3+ ions increased the fluorescence lifetime of Ce3+ ions by ∼17%， and improved the luminescence efficiency with the highest OCE of 270.56 lm/W. And Gd3+ ions increased the peak wavelength of emission from 554 nm to 564 nm and improved the Ra from 65.5 to 75.5. • The Ce,Tb,Gd:YAG-Al 2 O 3 ECPP has excellent performance with a low CCT of ∼4100 K and a CIE coordinate of (0.374, 0.364). • The CRI of Ce,Tb,Gd:YAG-Al 2 O 3 ECPP reached 73.0. [ABSTRACT FROM AUTHOR]

We report on the comparative growth and spectroscopy of Eu3+-doped Y 3 Al 5 O 12 (YAG) and Y 3 ScAl 4 O 12 crystals grown by the micro-pulling-down (μ-PD) method. The structure of the as-grown crystals was determined by X-ray diffraction (XRD) and Raman spectroscopy. The absorption spectra of the crystals are dominated by a strong line centered at 395 nm, matching well with the emission of commercial ultraviolet laser diodes. The Eu:YAG and Eu:Y 3 ScAl 4 O 12 crystals exhibit strongest red emission centered at 710 nm and the full width at half maximum (FWHM) was calculated to be 2.03 and 3.19 nm, respectively. The fluorescence decay curves of 5D 0 levels were measured and discussed. All the results indicate that the Eu:YAG and Eu:Y 3 ScAl 4 O 12 crystals are promising candidates for red luminescent/laser materials. • Eu:YAG and Eu:Y 3 ScAl 4 O 12 crystals were successfully grown by the micro-pulling-down technique for the first time. • The structure parameters of Eu:YAG and Eu:Y 3 ScAl 4 O 12 crystals were investigated by XRD. • Spectral parameters of Eu:YAG and Eu:Y 3 ScAl 4 O 12 crystals were obtained and compared. [ABSTRACT FROM AUTHOR]

High quality 7 at%Er:Y 2 O 3 crystal was successfully grown by Fz method. Judd-Ofelt theory was applied to analyze spectroscopic properties at 2.7 μm. The larger value of Ω 2 shows low local environment symmetry exists in Er:Y 2 O 3 crystal, and the large Ω 4 /Ω 6 indicates better spectral quality. The larger absorption cross-section and FWHM are beneficial to efficient absorption of pump source. The fluorescence spectra and lifetimes of Er:Y 2 O 3 crystal were measured and studied at 2.7 μm. The emission cross-sections at 2723 nm was calculated to be 1.41 × 10−20cm2. Compared with other Er3+ doped crystals, the large spectral quality factors Q and low fluorescence lifetime ratio illustrate that Er:Y 2 O 3 crystal has excellent laser properties at 2.7 μm. In addition, the low inversion ratio also indicates great potential of Er:Y 2 O 3 crystal for laser generation at 2.7 μm. • A high quality 7%Er:Y 2 O 3 laser crystal was successfully grown by Fz method. • Judd-ofelt (J-O) parameterization scheme was applied to analyze the spectroscopic properties of 7%Er:Y 2 O 3 laser crystal at 2.7 μm. • The large spectral quality factors Q with low fluorescence lifetime ratio illustrates that Er:Y 2 O 3 crystal has excellent laser properties at 2.7 µm. • The low inversion ratio indicates great potential of Er:Y 2 O 3 crystal for laser generation at 2.7 μm. [ABSTRACT FROM AUTHOR]

Nd3+ doped Y 3 Sc x Al 5-x O 12 (x = 0.05, 0.5, 1) single crystals were successfully grown by the micro-pulling-down (μ-PD) technique. The effect of compositional parameter x on the structure, absorption, emission and fluorescence lifetime of Nd:Y 3 Sc x Al 5-x O 12 crystals was studied. The Nd3+ concentration in the core increased with increasing of compositional parameter x. The full width at half maximum (FWHM) of the emission band centered at 1064 nm was calculated to be 6.1, 7.1, and 7.3 nm for x = 0.05, 0.5 and 1, respectively. The fluorescence lifetimes of 4F 3/2 levels are 259.3, 269.6, and 276.9 μs for x = 0.05, 0.5, and 1, respectively. The results indicate that the Nd:Y 3 Sc x Al 5-x O 12 crystals are promising materials for laser output. • Nd:Y 3 Sc x Al 5-x O 12 crystals were successfully grown by the micro-pulling-down technique. • Spectral parameters of Nd:Y 3 Sc x Al 5-x O 12 crystals were obtained. • The effect of composition on the structure and spectral parameters was discussed. [ABSTRACT FROM AUTHOR]

High optical quality Er3+ doped Lu 2 O 3 single crystal with optimum doping concentration was grown by Floating zone (Fz) method. The spectral properties and Judd-Ofelt (JO) analysis were reported. The emission cross-section at 2772 nm was calculated to be 2.47 × 10−20 cm2 with FWHM of 188 nm. The fluorescence lifetime of 4I 11/2 and 4I 13/2 energy level was fitted to be 1.62 ms and 4.02 ms. Optimum lifetime ratio (τ low /τ up) is beneficial to laser operation. Compared with reported Er3+ doped crystal, the larger spectral quality factors Q and low inversion ratio P of 7 at.% Er:Lu 2 O 3 crystal indicate that it has a favorable laser performance for 2.8 μm laser operation. • In our work high optical quality 7 at.% Er3+ doped Lu 2 O 3 single crystal with optimum doping concentration was grown by Floating zone method. • The spectroscopic properties were reported by Judd-Ofelt theory. • In order to weaken the influence of reabsorption phenomenon, we grind sample of Er:Lu 2 O 3 crystal into powder to measure fluorescence lifetime of 4I 13/2. • The measured fluorescence lifetime of 4I 13/2 is close to actual value. • We compare the optical characteristics of 7at.% Er:Lu 2 O 3 crystal with other materials in Mid-infrared. [ABSTRACT FROM AUTHOR]