Er3+:Yb3+共掺磷酸盐玻璃激光器输出特性研究

Er3+:Yb3+共掺磷酸盐玻璃激光器能发射1.54μm附近的激光,这种激光器广泛应用于光通信、激光雷达和人眼安全激光测距等方面。文章以输出波长为975nm的半导体激光器为泵浦源,采用Er3+:Yb3+共掺磷酸盐玻璃为工作物质,成功地实现了平平腔、平凹腔常温下连续输出TEM00模的1.54μm激光。实验结果表明:随着谐振腔腔长的增加,输出激光能量减小,而阈值功率增大。最后采用弯月型输出镜改善光束质量,获得了最大功率为30mW的1.54μm信号光输出。     

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     

掺Nd3+混晶全固态激光器研究进展

基于钕离子掺杂(Nd³⁺)的石榴石激光增益介质,为固体激光器的发展带来了新的研究方向。本文结合相关工作,详细全面地叙述了近年来掺钕混晶全固态激光器在单波长激光输出、多波长激光输出和脉冲激光输出方面的研究现状。以Nd∶LuYAG、Nd∶GdYAG和Nd∶GdLuAG为主要研究对象,分析总结了这三种混晶的研究价值,展望了Nd³⁺掺杂石榴石混合晶体的发展前景。     

内置Yb3+…YAG的环形腔输出脉冲激光理论分析

分析了Yb3+…YAG的发射光谱,按照均匀展宽的机理,对发射截面按照波长进行了划分,使之对应于Stark子能级对之间的跃迁。在此基础上,提出了内置Yb3+…YAG的环形腔将连续注入种子激光转换为超短脉冲激光的理论模型。基于速率方程方法,推导得到了描述脉冲激光性能的方程。在此过程中,考虑了Yb3+激光的抽运饱和吸收和自吸收效应。最后利用该模型分析了不同情况下的超短脉冲激光性能。结果表明,要实现性能优良的脉冲激光输出,必须选择合适的种子激光频率、光强和晶体长度等。     

LD侧面泵浦Er3+,Yb3+∶glass波导被动调Q激光器

报道了一种LD侧面泵浦铒镱共掺磷酸盐玻璃波导被动调Q激光器。采用无胶键合技术，在波导芯层(原子数分数1%Er³⁺,21%Yb³⁺∶glass)的四侧键合厚度为0.1 mm的掺钴硼硅酸盐玻璃(Co²⁺∶glass)作为包层，阻断放大自发辐射(ASE)的形成通路，提高激光输出效率。波导两侧分别键合硼硅酸盐K9光学玻璃作为泵浦光传输层，改善泵浦均匀性，提高输出激光的光束质量。在自由运转模式下，激光器输出的最大脉冲能量为34.7 mJ，斜率效率为10.6%。被动调Q模式下，获得稳定输出单脉冲能量2.16 mJ、脉宽4.7 ns、峰值功率459 kW的1.535μm脉冲激光，光束质量因子M²=1.53。实验结果表明，在Er³⁺,Yb³⁺∶glass的四侧键合Co²⁺∶glass是抑制其内部ASE效应、提高激光器单脉冲能量输出的有效方法。     

环形掺Er3+光纤激光器输出特性分析与实验研究

理论分析了掺Er3+光纤环形腔激光器的输出特性，获得了稳态条件下激光器输出功率、阈值泵浦功率和斜率效率的解析表达式，分析了泵浦光波长、泵浦功率、Er3+光纤掺杂浓度、输出端耦合器分光比等的影响，推导了在特定输出波长处获得最大输出功率所需最佳掺Er3+光纤长度的解析表达式。进行了LD泵浦掺Er3+光纤环形腔激光器的实验工作，获得了斜率效率10%以上的激光输出。     

1.3 μm Nd3+:YAG脉冲激光器的特性与设计

对Nd3+:YAG 1.3 μｍ波段的脉冲激光器进行了特性分析和实验研制。尤其是输出腔镜的最佳透过率的选择,谐振腔类型的选择,以及与1.06 μm脉冲器件的比较和改造。文中给出了最佳透过率,1.32 μm,1.34 μm两波长激光能量与输出镜透过率的关系等实验数据。     

LD端面抽运1.5μm Er3+,Yb3+∶YAl3（BO3）4激光器

报道了一种基于Er3+,Yb3+∶YAl3(BO3)4晶体的1.5μm固体激光器。为了解决由晶体严重的热效应所导致的激光器转化效率较低以及无法连续运转的问题,对控温炉设计以及抽运光源参数,如调制频率、占空比和腰斑尺寸等,进行了实验优化,从而减小了晶体的热负载,提高了准连续激光器的输出性能。在抽运源调制频率为40Hz,占空比为10%,抽运光腰斑半径为80μm,注入功率为17.6W时,获得了2.6W的准连续1.5μm激光输出,斜率效率为18.1%;同时在抽运功率为5W时,实现了290mW的连续单横模1.5μm激光输出,斜率效率为8.5%。     

LD端面抽运Yb3+∶YAG激光器输出功率的理论分析

从准三能级速率方程出发, 模拟分析了940 nm LD端面抽运Yb3+∶YAG输出1030 nm激光的性能。着重考虑了抽运光的吸收饱和以及Yb3+的自吸收损耗。结果表明, 由于输出波长在1030 nm附近的Yb3+∶YAG晶体存在严重的自吸收损耗, 入射功率必须足够强才能有激光输出, 因此激光器的阈值较高; 同时, 自吸收损耗与Yb3+离子浓度、晶体厚度有关, 存在最佳的晶体厚度和Yb3+离子浓度, 使激光器的输出功率最大。抽运光的吸收饱和使激光器运转时激光下能级的粒子数减小, 吸收系数下降, 激光器的输出功率较低。     

Yb3+-Er3+玻璃光激射器

在硅酸盐玻璃中能量自Yb3+离子转移至Er3+离子时,可使Er3+离子产生受激振荡,在室温下为三能级机构,输出波长为1.5426微米。在此之前,曾报导过Er3+掺入CaWO4中,但是它是作为四能级系统,在77 °K时,输出波长为1.612微米。     

Er3+-Yb3+ and Er3+ doped fiberlasers

Single-mode fiber lasers operating at ~1.57 μm are described. Output powers of >2 mW are reported for laser diode pumped operation. Direct comparison is made between fiber lasers using sensitized erbium (Er³⁺ and Yb³⁺) and erbium on its own. The performance of Er³⁺-Yb³⁺ fiber lasers is analyzed in more detail as a function of fiber length. Both CW and Q-switched operations are studied and the results obtained demonstrate that practical sources at 1.5 μm are available from diode pumped Er³⁺ -Yb³⁺ systems     

Infrared cross-section measurements for crystals doped withEr3+, Tm3+, and Ho3+

The absorption and emission cross sections of the transition between the ground spin-orbit multiplet and the lowest excited multiplet were measured for Er³⁺, Tm³⁺, and Ho³⁺ ions in a variety of crystalline hosts. The materials that were investigated include LiYF₄, BaY₂F₈, Y ₃Al₅O₁₂, LaF₃, KCaF₃ , YAlO₃, and La₂Be₂O₅. The absolute magnitudes of the emission cross sections were determined from the absorption spectra, with the aid of the principle of reciprocity. The calculated radiative emission lifetimes derived from these measured cross sections agree well with the measured emission decay times for most materials. The potential use of these rare-earth-doped materials in pulsed laser applications requires that the ground state exhibit adequate splitting to minimize the detrimental effects of the ground state thermal population, and also that the emission cross section be sufficiently large to permit efficient extraction energy. The systems based on Ho³⁺ in the eightfold coordinated sites of LiYF₄, BaY₂F₈, and Y₃Al₅O₁₂ appear to be the most promising     

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     

Laser action from Ho3+, Er3+, and Tm3+in YAlO3

Laser action has been observed for the following rare-earth ions in YAlO3:Ho³⁺(sensitized with Er³⁺and Tm³⁺), Er³⁺, and Tm³⁺(sensitized with Er³⁺) at wavelengths of 2.123, 0.851, and 1.861 μm, respectively. Measurements of spectroscopic properties, fluorescence kinetics, and laser performance of these ions in YAlO3are reported.     

Er3+/Yb3+双掺光纤放大器理论模型

本文在分析一些文献的基础上,仿照掺Er3+光纤放大器的理论模型,尝试建立了一个Er3+/Yb3+双掺光纤放大器的理论模型。利用本模型,可以模拟双掺光纤中信号、泵浦及放大的自发辐射(ASE)的变化情形,并得到一些有意义的数值结果。     

Diode-array pumping of Er3+/Yb3+ Co-dopedfiber lasers and amplifiers

Single-mode double-clad Er³⁺/Yb³⁺ co-doped fibers are shown to be suitable for diode array pumping at around 960 nm. A fiber laser with 96-W output power at 1.53 μm and a power amplifier exhibiting a small signal gain of 24 dB and a saturated output power of +17 dBm are reported     

磷酸盐玻璃中稀土离子Ce~(3 )、Tb~(3 )、Er~(3 )和Tm~(3 )的能量转移和敏化过程的研究

本文报道了磷酸盐玻璃中Tb~(3 )和Ce~(3 )的浓度猝灭效应。在KrF激光(248毫微米,10毫微秒)激发下,测出磷酸盐玻璃中不同浓度Ce~(3 )或Tb~(3 )离子的荧光寿命。着重讨论了磷酸盐玻璃中Ce~(3 )→Tb~(3 )、Er~(3 )和Tm~(3 )的能量转移和敏化过程。     

Ag纳米颗粒对Er3+/Tm3+/Yb3+共掺铋锗酸盐玻璃上转换发光特性的影响

采用传统熔融淬冷法制备了系列Er³⁺/Tm 3+/Yb³⁺共掺复合Ag纳米颗粒的铋锗酸盐玻璃样品。从吸收光谱中 确定了Ag纳米颗粒表面等离子体共振(SPR)峰位于545nm附近;透射 电镜(TEM)图像中观察到均匀分布的Ag纳米颗粒,尺寸 约为6～18nm。研究了纳米Ag含量对Er3＋/Tm3＋ 共掺复合Ag纳米颗粒铋锗酸盐玻璃上转换发光特性的影响,结果表 明,Tm³⁺离子472nm处的上转换蓝光、Er³⁺离子525nm处的上转换绿光、543nm处的上转换 绿光和661nm处的上转换红光发光强度在AgCl含量的质量百分数为 1%时达到最大值,与未掺杂AgCl的基质玻璃相比,分别提高了约3.2、3.8、5.4倍。     

Anomalous dispersion in Er3+ and Yb3+-dopedfibers

In experimental and theoretical study of anomalous dispersion in Er³⁺and Er³⁺-Yb³⁺-doped fibers has been developed. Anomalous time delay caused by both absorption and emission at 1.535 μm has been theoretically calculated and experimentally measured. A pump power dependence of anomalous time delay in rare-earth-doped fibers has been theoretically calculated and experimentally investigated. It has been shown that pump power fluctuations lead to propagation time jitter in Er³⁺-doped fiber amplifiers. The pulse interaction due to refractive index change caused by gain saturation is predicted. It has been shown that for Er ³⁺-doped fibers with SiO₂-GeO₂ core composition, the anomalous dispersion per 1-dB gain is twice that of fibers with SiO₂-Al₂O₃ core, which is caused by gain curve form difference. A scheme of mutual compensation of intrinsic fiber dispersion and anomalous dispersion caused by Er³⁺ in the region 1.532-1.537 μm has been suggested     

Li-La磷酸盐激光玻璃Cr~(3+)→Nd~(3+)敏化

本文对Li-La磷酸盐玻璃单掺Cr~(3+)离子及双掺Cr~(3+)、Nd~(3+)离子的光谱性质进行了研究,测定了玻璃的吸收光谱、荧光光谱和荧光寿命。Li-La磷酸盐玻璃中Cr~(3+)→Nd~(3+)的能量转移效率为38％,最适当的钕离子浓度为2×10~(21)cm~(-3),Cr_2O_3含量≥0.1wt％。