高功率高重复频率全固态激光器热透镜效应补偿与分析

将kHz高功率固体激光器增益介质当作厚透镜处理，建立了热透镜效应分析的理论模型，使用矩阵的方法对等效热透镜腔进行分析。对增益介质抽运均匀性进行了改善，通过分析模拟计算结果。设计了混合非稳腔结构，选择了最佳凸面镜曲率半径对热透镜效应进行补偿。试验结果表明，补偿效果明显，kHz高功率全固态激光器的光束发散角优于1．3mrad。

板条激光放大器中寄生振荡的研究

寄生振荡的存在使得放大器在信号光到达之前消耗了大量的反转粒子数,降低了放大器的激光增益和储能效率,严重地影响了激光放大器的性能,尤其对高功率激光放大器。在理论分析和实验研究的基础上,以Nd∶YAG晶体板条为例,用8条半导体激光阵列对晶体进行双侧抽运,研究了高功率激光放大器的寄生振荡现象,分析了板条晶体寄生振荡产生的原因,并详细比较了晶体在不同的抽运功率和表面处理下的放大效果,得到了2倍的单程放大,当输入能量为140 mJ时,获得了278 mJ的激光输出。

Yb：Y2O3透明陶瓷的光学性能研究

介绍了一种基于纳米粉末真空烧结技术的新型固体激光材料——Yb：Y2O3多晶陶瓷的制备工艺、物理化学特性、能级结构和光谱特性，并与Yb：YAG单晶进行了对比．采用紧凑型有源镜激光器（CAMIL）的抽运方式，验证了Yb：Y2O3透明陶瓷的激光输出性能．在35W的最大抽运功率下，得到波长1078nm，功率10．5w的连续激光输出，斜率效率达到37．5％．实验中还观察到激光输出波长随抽运功率增加而红移以及随输出耦合镜变化而漂移的现象．Yb：Y2O3多晶陶瓷是一种理想的激光材料，不仅具有与Yb：YAG单晶同样优秀的

高功率脉冲双包层光纤激光器的新进展

对高功率脉冲双包层光纤激光器的国内外研究进展进行评述，通过建立了小信号瞬态增益模型，对脉冲激光信号经过双包层光纤放大后的波形进行了数值模拟。分析了基于MOPA方式脉冲双包层光纤激光器的几个问题，报道了中科院上海光机所采用振荡-放大（MOPA）方法获得133．8W平均功率脉冲放大输出的实验结果。

两微米瓦级掺铥短光纤激光器

以短的高掺杂浓度的掺铥硅基光纤为增益介质，采用790 nm波长的激光二极管(LD)为抽运源，得到了波长为2 μm的高功率激光输出。当光纤长度为7 cm时，激光器的阈值泵浦功率为135 mW，最大输出功率为1.09 W，斜率效率为9.6%(相对于耦合进光纤的抽运功率)。该激光器的输出稳定性在5%以内。此外，我们还观察分析了工作温度和其他腔结构参量对该激光器工作性能的影响。

千瓦级双包层光纤激光器冷却方案设计理论和实验研究

尽管双包层光纤激光器的散热性能好于传统的固体激光器的散热性能,光纤激光器中的热沉积仍然是限制提高其输出功率的重要因素.以双端抽运的400W双包层光纤激光器为实例,定量分析了光纤内的热沉积分布.根据所建立的散热模型,为了确保千瓦级双包层光纤激光器安全稳定的运行,抽运端附近的对流换热系数应大于2.8×10-2W·cm-2K-1.据此设计出高功率双包层光纤激光器抽运端冷却装置并成功应用在激光系统中,获得了千瓦级的激光输出.

瓦级双包层光纤超荧光光源的实验研究

采用大功率半导体激光器抽运25m掺Yb双包层光纤，在单程装置中，前向(SPF)和后向(SPB)分别获得了1．46w和1．82w最大超荧光功率，斜度效率分别为23．4％0和29．2％，3dB带宽最大为11nm。采用特定范围波长双色镜作为前腔镜，形成双程前向(DPF)装置，获得最大超荧光输出功率2．12W，此时斜度效率为43．2％，中心波长在1070nm，输出光谱平坦性较好，3dB带宽从单程的11nm提高到42nm。

Self-formation of quasiperiodic void structure in CaF2 induced by femtosecond laser irradiation

We report the self-formation of quasiperiodic void structure with the length of several hundred micrometers inside the CaF2 crystal. The quasiperiodical voids along the propagation direction of the laser beam were formed spontaneously after the irradiation of a single femtosecond laser beam which was focused at a fixed point inside the crystal sample. The length of the void array varied with the focal depth beneath the sample surface. The possible mechanism of the self-formed void structure was discussed. (c) 2007 American Institute of Physics.

高硅氧发光玻璃的制备及其荧光性能

abstract {Silica glass is an attractive host matrix for the emission ions of rare earth and transition metal ions because it has small thermal expansion coefficient, strong thermal resistance, large fracture strength and good chemical durability and so on. However, a major obstacle to using it as the host matrix is a phenomenon of concentration quenching. In this paper, we introduces a novel method to restrain the concentration quenching by using a porous glass with SiO₂ content > 95% (in mass) and prepare intense fluorescence high-SiO₂ glasses and high-SiO₂ laser glass. The porous glass with high-SiO₂ content was impregnated with rare-earth and transition metal ions, and consequently sintered into a compact non-porous glass in reduction or oxidization atmospheres. Various intense fluorescence glasses with high emission yields, a vacuum ultraviolet-excited intensely luminescent glass, high silica glass containing high concentration of Er³⁺ ion, ultrabroad infrared luminescent Bi-doped high silica glass and Nd³⁺-doped silica microchip laser glass were obtained by this method. The porous glass is also favorable for co-impregnating multi-active-ions. It can bring effective energy transferring between various active ions in the glass and increases luminescent intensity and extend range of excitation spectrum. The luminescent active ions-doped high-SiO₂ glasses are potential host materials for high power solid-state lasers and new transparent fluorescence materials.}

钕离子掺杂和钕铝共掺高硅氧玻璃的光谱性质研究

Nd-doped and Nd-Al-codoped high silica glasses were obtained by sintering porous glass impregnated with Nd3+ and Al3+ ions. The absorption, fluorescence spectra and fluorescence lifetime of Nd-doped and Nd-Al-codoped high silica glasses were measured. The intensity parameters Omega(1), ( t = 2, 4, 6), fluorescence lifetime, radiative quantum efficiency and stimulated emission cross section were calculated by Judd-Ofelt theory. The effect of aluminum codoping on the fluorescence and structural properties of Nd-doped silica glass has been discussed. By comparing the spectroscopic properties with other Nd-doped oxide glasses and commercial silicate glasses, this Nd-doped high silica glass is likely to be a promising laser material for use in high power and high repetition rate lasers.

Thermal analyses, spectral characterization and structural interpretation of Yb3+ doped TeO2-ZnO-ZnCl2 glasses

Bulk-lasses have been prepared in the TeO2-ZnO-ZnCl2 systems. Their characteristic temperatures were determined and analyzed. Raman and FT-IR spectra were used to analyze the effect of ZnCl2 on the structure and spectral properties of tellurite glasses and OH- groups in this glass system. The spectroscopic properties including absorption spectra, emission cross-sections and fluorescence lifetimes of Yb3+ in TeO2-ZnO-ZnCl2 were measured and calculated. It is demonstrated that the progressive replacement less than 20 mol% of TeO2 by ZnCl2 improves the thermal stability, removes the OH- groups, turns TeO4 bipyramidal arrangement into TeO3 (and/or TeO3+1) trigonal pyramids structures and results in the decrease of the symmetry of the structure, which increases the emission cross-sections and lifetimes. But when the content of ZnCl2 up to 30 mol%, the glass system becomes more hygroscopic and introduces more OH- groups, which decrease the emission cross-sections and shorten the lifetimes. The results show that the glass system with (TeO2)-Te-69-(ZnO)-Zn-10-20ZnCl(2)-1Yb(2)O(3) is a desirable component for active laser media for high power generation. (c) 2005 Elsevier B.V. All rights reserved.

Effect of F- ions on emission cross-section and fluorescence lifetime of Yb3+-doped tellurite glasses

The effects of F- ions in Yb3+-doped tellurite glass systems on the emission cross-section and measured fluorescence lifetime are investigated. The results show that both the emission cross-section and the fluorescence lifetime of Yb3+ ions increase from 1.32 to 1.39 pm(2) and from 0.93 to 1.12 ms respectively with the increase of F- ions from 0 to 10 mol% and that such oxyfluoride tellurite glass system is a promising laser host matrix for high power generation. FT-IR spectra were used to analyze the effect of F- ions on the structure of tellurite glasses and the change of OH- groups in this glass system. Analysis demonstrates that the addition of fluoride decreases the symmetry of the structure of tellurite glasses resulting in increasing of the emission cross-section and removes the OH- groups resulting in increasing of the measured fluorescence lifetime of Yb3+ ions. (c) 2005 Elsevier B.V. All rights reserved.

Effect of F- ions on physical and spectroscopic properties of Yb3+-doped TeO2-based glasses

The effects of F- ions on physical and spectroscopic properties of the Yb3+ in tellurite glass system are investigated. The results show that the glass system takes on good thermal stability with the content of ZnF2 lower than 15 mol%, both the emission cross-section and the fluorescence lifetime of Yb3+ ions increase evidently which indicate that such oxyfluoride tellurite glass system is a promising laser host matrix for high power generation. FT-IR spectra were used to analyze the effect of F- ions on the structure of tellurite glasses and OH- groups in this glass system. Analysis demonstrates that addition of fluoride decreases the symmetry of the structure of tellurite glasses which increases the emission cross-section and removes the OH- groups, and which improves the measured fluorescence lifetime of Yb3+ ions. (c) 2004 Elsevier B.V. All rights reserved.

Fluorescence lifetime increasing with F- ions into ytterbium-doped germanium-lead-tellurite glasses

The effects of F- ions in a germanium-lead-tellurite glass system oil the spectral and potential laser properties of the Yb3+ are investigated. The absorption spectra, lifetimes, the emission cross-sections and the minimum pump intensities of the glass system with and without F- ions have been measured and calculated. The results show that the fluorescence lifetime and the minimum pump intensity of Yb3+ ions increase evidently, which indicates that germanium lead-oxyfluoride tellurite glass is a promising laser host matrix for high power generation. FT-IR spectra were used to analyse the effect of F- ions on OH- groups in this glass system. Analysis demonstrates that addition of fluoride removes the OH- groups and results in improvement of fluorescence lifetime of Yb3+.

Fluorescence lifetime increase by introduction of F- ions in ytterbium-doped TeO2-based glasses

this paper was retracted