双掺Er^(3+)/Yb^(3+)∶Sr_3La_2(BO_3)_4晶体的生长与光谱特性

采用提拉法生长了尺寸为20mm×30mm的Er3+/Yb3+∶Sr3La2(BO3)4晶体,研究了Er3+/Yb3+∶Sr3La2(BO3)4晶体的吸收光谱和荧光光谱。根据Judd-Ofelt理论分析并计算了辐射跃迁几率、辐射寿命、荧光分支比等光谱参数,获得的唯象参数为:Ω2=15.59×10-20cm2,Ω4=2.25×10-20cm2,Ω6=1.49×10-20cm2。在Er3+/Yb3+∶Sr3La2(BO3)4晶体中Er3+在1533nm处发射跃迁截面为7.88×10-21cm2,Er3+的4I13/2→4I15/2能级跃迁的荧光寿命和辐射寿命分别为0.728ms和4.24ms,结果表明Yb3+对Er3+有敏化作用,提高了对泵浦光的吸收能力,Er3+/Yb3+∶Sr3La2(BO3)4晶体可望作为1.55μm波段的一种有潜力的激光材料。

Er^3＋／Yb^3＋：Sr3Y2(BO3)4晶体的光谱和激光性质

采用提拉法生长了双掺Yb3+和Er3+离子浓度分别为18.63%和0.87%(原子分数)的Sr3Y2(BO3)4晶体。利用测量的偏振吸收谱结合Judd-Ofelt理论,拟合得到了该晶体中Er3+离子的偏振和有效J-O参数。测量了Er3+离子4I13/2能级和Yb3+离子2F5/2能级的荧光衰减曲线,并计算了4I13/2能级的荧光量子效率和Yb3+到Er3+的能量传递效率。利用Fuchtbauer-Ladenberg公式计算了Er3+离子4I13/2→4I15/2跃迁的偏振受激发射截面。在平-凹谐振腔中,利用970 nm波长光纤耦合准连续半导体激光端面泵浦1.12 mm厚的该晶体,当输出镜透过率为1.5%时,获得了最大输出功率为1.3 W和斜率效率为20%的1560 nm附近的激光输出。结果表明,Er3+/Yb3+:Sr3Y2(BO3)4晶体是一种优良的1.5～1.6μm波段激光的增益介质。

Growth and Spectroscopic Properties of Nd^(3+):Sr_3Gd_2(BO_3)_4 Crystal

This paper reports the growth, X-ray diffraction and spectroscopy of Nd3＋：Sr3Gd2（BO3）4 crystal. A Nd3＋：Sr3Gd2（BO3）4 crystal with dimensions of φ20 × 45 mm3 has been grown by the Czochralski method. Nd3＋：Sr3Gd2（BO3）4 crystal belongs to the orthorhombic system, space group Pnma （D2h） with a = 0.7401, b = 1.604 and c = 0.8755 nm. The absorption and emission spectra of Nd3＋：Sr3Gd2（BO3）4 were investigated. The absorption cross section oa is 3.11 × 10^-20cm2 at 808 nm. The absorption transition at 808 nm has an FWHM of 14 nm. The luminescence lifetime τf is 51.7 μs. The emission cross section oc at 1064 nm wavelength is 1.09 × 10^-19 cm2.

Growth and Structure of Sr_3Yb_2(BO_3)_4 Crystal

A Sr3Yb2（BO3）4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 （BO3）4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pnma with a=7.3750（8）, b=15.9265（14）, c=8.6776（9）, V=1019.25（18）3 , Mr=844.18, Z=4, Dc=5.501 g/cm3 , λ（MoKa）=0.71073, μ= 33.835 mm-1 , F（000）=1480, the final R=0.0339 and wR=0.0907 for 1090 observed reflections with I〉2σ（I）. The structure features a three-dimensional framework composed of isolated BO3 planar triangles bridged by YbO8 and SrO8 polyhedra. The Sr2＋ and Yb3＋ occupy statistically three independent sites with a Cm and two C1 local symmetries.

Polarized spectral analysis of Er^(3+) ions in Er^(3+)/Yb^(3+):LiLa(MoO_4)_2 crystal

Optical characteristics and upconversion dynamics of Er3+ in Er3+/Yb3+:LiLa(MoO4)2 crystals were investigated. The absorption spectra, fluorescence spectra and the fluorescence decay curves were analyzed at room temperature. The infrared emission at 1538 nm and visible emissions at 520–569 and 640–670 nm, corresponding to 2H11/2,4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+ ions, were simultaneously observed in Er3+/Yb3+:LiLa(MoO4)2 crystals under 976 nm excitation at room temperature. The maximal emiss...

NaY(WO_4)_2:Yb^(3+),Er^(3+)晶体的光学性质

用 Czochralski方法生长了 Yb3+ ,Er3+共掺的 Na Y(WO4) 2 晶体。测量了晶体在室温下的吸收谱 ,用 Judd- Ofelt理论计算了 Na Y(WO4) 2 :Er3+ ,Yb3+晶体中 Er3+的 3个唯象强度参量 Ω2 =18.10× 10 - 2 0、Ω4=2 .5 9× 10 - 2 0、Ω6 =1.2 1× 10 - 2 0和辐射跃迁特征参量。研究了晶体的荧光特性 ,并在 974nm的 L D泵浦下得到上转换绿色荧光。分析了晶体中 Yb3+向 Er3+传递能量的机制。

High-repetition-rate 1.5 μm passively Q-switched Er:Yb:YAl3(BO3) 4 microchip laser

End-pumped by a 976 nm diode laser,a high-repetition-rate Er:Yb:YAl3(BO3)4 microchip laser passively Q-switched by a Co2+:MgAl2 O4 crystal is reported.At a quasi-continuous-wave pump power of 20 W,a 1553 nm passively Q-switched laser with the repetition rate of 544 kHz,pulse duration of 8.3 ns,and pulse energy of 3.9 μJ was obtained.To the best of our knowledge,the 544 kHz is the highest reported value for the 1.5 μm passively Q-switched pulse laser.In the continuous-wave pumping experiment,the maximum repetition rate of 144 kHz with the pulse duration of 8.0 ns and pulse energy of 1.7 μJ was obtained at the incident pump power of 6.3 W.

基于a切Er,Yb:YAl_(3)(BO_(3))_(4)晶体被动调Q微片激光器

报道了基于a切Er,Yb:YAl3(BO3)4晶体的被动调Q微片激光器的性能。使用波长为976 nm的光纤耦合半导体二极管作为端面抽运光源,使用初始透过率为96%的Co^(2+)∶MgAl_(2)O_(4)晶体作为可饱和吸收体,耦合输出镜在1500~1600 nm波段范围的透过率为2.5%,整个微片激光器的腔长为2.7 mm。在注入功率为7.2 W时,激光器成功得到了发射波长为1530 nm、重复频率为127 kHz的稳定线性偏振的脉冲输出,对应的脉冲能量和脉冲宽度分别为1.8μJ和12 ns。