BeAl_2O_4:Cr~(3 )晶体的激光性能实验

获得了BeAl_2O_4:Cr~(3 )晶体的电子—振动激光输出。自由振荡阈值170焦耳,输出激光能量140毫焦耳,激光中心波长为7526埃。激光具有与结晶学b轴相平行的线偏振特性。用石英双折射滤光片作调谐元件,看到了激光的调谐输出。     

BeAl_2O_4:Cr~(3+)晶体激光性能的改进

报道了改进BeAl_2O_4:Cr~(3+)晶体激光性能的几项措施。得到的晶体的激光振荡阈值大大降低,而激光器输出能量及调谐范围提高。     

BeAl_2O_4:Cr~(3+)晶体激光性能的改进

通过对BeAl_2O_4:Cr~(3+)晶体生长工艺的改进及精密退火处理,晶体的光学均匀性及内耗有了较大改进。通过对激光系统的参数选择,转换效率、聚光效率及腔内损失也为之改善。在此基础上,已将激光振荡阈值降低到34J,输出能量增加到593mJ(输入196J),斜率效率达到0.6%。调谐范围从735.7～796.1nm。用LiF:R~-心调Q,输出线宽大约为0.001nm。不     

BeAl_2O_4:Cr~(3 )晶体已得到电子-振动激光输出

BeAl_2O_4:Cr~(3 )(Alexandrite)晶体是近几年来新发展的激光材料。用光泵激励,既可实现R线激光(6804(?))运转,也可以实现可调谐的电子-振动激光(调谐范围7010～8180(?))运转。因而在国内外颇受人们重视。美国联合化学公司对这种材料的生长与激光性能研究作过较全面的报导。苏联地质与地球物理研究所也对此作过多年的研究并报导过所获得的结果。     

引上法生长可调谐激光晶体BeAl_2O_4:Cr~(3+)

掺铬铝酸铍晶体作为可调谐激光晶体,在近几年来颇受国内外重视。这种晶体激光器能室温运转,可调谐范围宽,结构简单,输出功率高。目前在民用或军事应用上已开始应用,有可能会有更广泛的应用。我们的工作表明,铬酸铍晶体生长的研究中主要存在着防毒、铝酸铍相形成动力学以及熔体老化等特殊问题。 (1)我们在配料过程中,为防铍尘毒害,改革了操作设备、工艺条件,使配料间内的空气中铍含量降至0.5微克/米~3,符合国家劳保条例的要求。 (2)由于我们配料条件不同,铝酸铍相形成条件与粉末混匀料不同。实验表明,铝酸铍相     

金绿宝石BeAl_2O_4∶Cr~(3 )中高压荧光动力学

本文报道了金绿宝石BeAl_2O_4∶Cr~(3 )在高压下的荧光动力学行为。这是一种新型激光材料,利用它已制成第一个室温运转的固体可调谐声子态激光器。实验结果表明:(1)R_1和R_2线随压力线性地红移,但和红宝石不同,其红移速度不相等,分别为0.62 cm~(-1)/kbar和0.71 cm~(-1)/kbar。因此,R_1和R_2线将逐步随压力升高而靠     

BeAl_2O_4:Cr~(3+)激光泵浦的NaF:F_2~+心的受激发射

本文报道首次用工作在755nm的BeAl_2O_4:Cr~(3+)重复率脉冲激光器泵浦NaF:F_2~+心,得到了波长为950nm的受激发射(谱宽20nm)。有趣的是,尽管泵浦光是一系列的自由振荡脉冲,而得到的NaF:F_2~+心的950nm受激发射却总是只有一个很窄的脉冲,其脉宽为20ns。BeAl_2O_4:Cr激光器输出的自由振荡脉冲系列分布在大约140μs的时间里,每个脉冲的宽度都在1μs的量级。因此,获得宽度不大于20ns的单个脉冲这一事实说明,对于产生这样的受激发射,只有第一个超过阈值的泵浦脉冲     

BeAl_2O_4:Ni~(2 )晶体光谱性能的研究

本文首次报道了BeAl_2O_4:Ni~(2 )晶体的吸收光谱和荧光光谱,在近红外获得了半宽度大于2000的荧光峰,室温荧光寿命为190μs。根据晶体场理论研究了光谱特性,初步确定出Ni~(2 )在BeAl_2O_4晶体中的能级结构,讨论了BeAl_2O_4:Ni~(2 )晶体成为终端声子可调谐激光晶体的可能性。     

BeAl_2O_4:Cr~(3 )单晶的熔盐法生长及其光谱特性的研究

采用熔盐法从PbF_2—PbO—B_2O_3三元系高温溶液中生长出掺Cr~(3 )的BeAl_2O_4单晶,通过严格控制降温速率(约2℃/小时)和熔剂成份的摩尔比值(45P_bF_2:45P_bO:10B_2O_3)获得了尺寸达10×4.5×4.5mm~3的块状透明晶体。 在5K.77K和300K不同温度下测量了Cr~(3 ):BeAl_2O_4单晶的非偏振吸水谱、荧光谱和激发谱(T=300K),首次由实验确定出在C_(1h)低对称场微扰下Cr~(3 )离子的~2T_1和~2T_2能级分裂出的三个亚能级的位置。     

Ni~(2 ):BeAl_2O_4晶体的红外荧光及其寿命研究

本文首次报道用激光诱导荧光法测量Ni~(2 );BeAl_2O_4晶体~3T_2→~3A_2电子振动跃迁的荧光及其寿命的结果。测得室温下荧光的中心波长为1.33μm,带宽(FwHM)为0.14μm(1.26～1.40μm),荧光谱中心相对于吸收谱中心的红移为0.225μm,~3T_2态的辐射寿命为198μs。     

Flashlamp-pumped Cr3+:GSAG laser

Flashlamp-pumped vibronic lasing has been demonstrated at room temperature with the garnet Cr³⁺: GSAG. Continuous wavelength tuning was observed from 765 to 801 nm in preliminary experiments. An energy output of 110 mJ/pulse was obtained at 784 nm with a slope efficiency of 0.12 percent. Wavelength dependent gain and loss data are presented and are discussed with reference to Cr³⁺: GSGG measurements.     

BHA:Cr~(3+)(BeO·3Al_2O_3:Cr~(3+))晶体的荧光特性

本文对新晶体BHA:Cr~(3+)(BeO·3Al_2O_3:Cr~(3+))的荧光谱进行了仔细辨认,发现晶体中存在着几种不同的发光中心。提出了不同Cr离子中心之间的能量传递模型。     

Ni~(2+):BeAl_2O_4激光晶体的红外荧光光谱及能级热移位特性的研究

文献[1]报道了Ni~(2+):BeAl_2O_4晶体的晶场能级与Ni~(2+)离子在晶体中择位与电荷补偿机理的研究结果,指出该晶体的红外荧光来源于处于具有C_2对称畸变的八面体格值上的Ni~(2+)离子~3T_(2g)→~3A_(2g)跃迁发光.但未能考虑谱宽、能级位置与低对称劈裂对于发光的影响.为了研究用Ni~(2+):BeAl_2O_4晶体制成激光器的工作稳定性与调谐功能等工作特性的需要,进一步研究温度对于该晶体发光特性的影响是十分必要的,     

Investigation of the laser properties of Cr3+:LiSrGaF6

A boule of Cr:LiSGAF (Cr³⁺:LiSrGaF₆), the Ga analog of Cr:LiSAF, was grown, a laser sample was fabricated, and its efficiency was measured using a laser-pumped laser configuration. The laser performance near 820 nm and related properties of Cr:LiSGAF are reported. The use of Sr instead of Ca results in a red shift of the absorption and emission band (along with an increase in the emission cross section). Insight into the effect of a change in the identity of the substitutional site on the properties of the laser is provided     

Er3+,Yb3+:glass/Co2+:MgAl2O4复合材料LD泵浦被动调Q微型激光器

报道了一种应用于激光测距的Er³⁺,Yb³⁺:glass/Co²⁺:MgAl₂O₄复合材料LD泵浦的被动调Q微型激光器。 采用玻璃与晶体复合技术,将增益介质Er3＋/Yb3＋共掺 磷酸盐玻璃和被动调Q可饱和 Co²⁺:MgAl₂O₄晶体进行了光学热复合,复合材料会降低增益介质内部的温度梯度 ,使热焦距变长,模体积 增加,激光光束质量提高;另外,复合材料使腔内损耗减小,腔内的粒子数密度提高,脉宽 变窄,输出能 量增加,从而激光器性能得到提高。在重复频率为10Hz情况下,采 用中心波长为940nm的单管LD作为泵 浦源,获得单脉冲能量为210μJ、脉冲宽度为2.8ns,峰值功率大于70kW的波长为1.5 μm的被动调Q激光输出,光束质量为1.2     

Cr3+→Nd3+ energy transfer and Nd3+ laser action studies of La3Ga5SiO14:Cr3+,Nd3+ co-doped crystal

Energy transfer between Cr³⁺ and Nd³⁺ ions has been investigated in the 4.2-300-K temperature range by using steady-state and site-selective time-resolved laser spectroscopy. Radiative and nonradiative energy transfer has been studied from the time-resolved emission spectra and the donor fluorescence decays. The transfer efficiency was calculated as a function of temperature by using the Cr³⁺ lifetimes of the single doped and co-doped samples. Laser experiments were carried out in a diffusive cavity by pumping a co-doped rod 54 mm long and 5 mm in diameter with xenon flashlamps. The laser spectral emission shows a complex structure which varies as a function of pump energy. The temporal evolution of the laser spectrum is discussed in terms of a simple four-level spectral rate-equation laser model which takes into account the existence of two main broad Nd³⁺ site distributions with a large spectral overlap     

激光晶体Y3Ga5O12:Cr3+的MS-Xα计算

本文报道了具有D3d格位对称性的过渡金属络合离子团[CrO6]9-的自旋非限制MS-Xα计算结果.给出了单电子本征值与本征函数.讨论了激光晶体Y3Ga5O12:Cr3+的电子结构.用Slater过渡态方法计算了晶场分裂参数10Dq及晶场低对称畸变引起的电子能级分裂值及一些反映局域电子结构的参数.计算结果与实验符合较好.     

Tunable Cr4+:YSO Q-switched Cr:LiCAF laser

Tunable passive Q-switching (781 nm to 806 nm at 300 K) of a flash-lamp pumped Cr³⁺:LiCaAlF₆ (Cr:LiCAF) laser with a Cr⁴⁺:Y₂SiO₅ (Cr⁴⁺:YSO) broad-band solid-state saturable absorber has been realized. Typical pulse widths of the Q-switched laser output ranged from 40 ns to 80 ns, depending on the lasing wavelength. Spectral narrowing and reduced beam diameter with the use of the saturable absorber were observed. The ground state and the excited state absorption cross sections of the Cr⁴⁺:YSO absorber were found by bleaching experiments to be (7.0±1.4)×10^-19 cm² and (2.3±0.5)×10^-19 cm² at 694 nm, respectively. Numerical simulation was utilized to simulate the Cr:LiCAF passive Q-switching with Cr⁴⁺ :YSO solid-state saturable absorber     

Sub-100 fs Kerr lens modelocked Cr4+:YAG laser

Sub-100 fs pulse generation from a Kerr lens modelocked Cr⁴⁺ :YAG laser has been demonstrated for the first time, yielding femtosecond pulses tunable from 1.49 to 1.56 μm with pulses as short as 90 fs obtained at 1.53 μm