Yb掺杂原子数分数为0．5％的Yb：Y3Al5O12晶体的光谱分析

采用提拉法生长了Yb掺杂原子数分数为0．5％的Yb：Y3Al5O12。（Yb2YAG）晶体，对晶体的吸收光谱和荧光光谱进行了分析。与Yb掺杂原子数分数为5％的Yb：YAG晶体进行了对比，得出采用940nm激光二极管（LD）抽运晶体最为合适。原子数分数为0．5％的Yb：YAG晶体相对于原子数分数为5％的Yb：YAG晶体白吸收效应的影响要小。测量了原子数分数为0．5％的Yb：YAG晶体的荧光寿命为0．95ms，与理论值很接近。因此采用原子数分数为0．5%的Yb：YAG晶体作为激光工作物质将有利于高效、小型集成

不同Yb掺杂量的Yb：Y3Al5O12晶体的光谱分析

采用提拉法生长了Yb^3＋掺杂量分别为5．4at％，16．3at％，27．1at％，53．6at％和100at％的Yb：Y3Al5O12晶体．系统地表征和分析了Yb^3＋掺杂量对晶体吸收光谱和荧光光谱的影响．随着Yb^3＋掺杂量的增加，各峰值吸收系数呈线性增加的趋势．应用Smakula公式计算了各吸收峰对应的振荡强度，并分析了Yb^3＋掺杂量对振荡强度的影响．当Yb^3＋掺杂量增加到27．1at％时观察到了荧光猝灭现象；当Yb^3＋掺杂量增加到53．6at％时，荧光光谱的线形发生了很大的变化。

Characterization of diode-pumped laser operation of a novel Yb : GSO crystal

We report what is believed to be the first demonstration of the laser action of Yb3+ -doped Gd2SiO5 (Yb:GSO) crystal pumped by a 940-nm laser diode at room temperature. The threshold of laser generation is only 0.85 kW/cm(2), which is smaller than the theoretic threshold of Yb:YAG (1.54 kW/cm(2)). The laser wavelength is 1090 mn. With a 2.5% output coupler, the maximum output power is 415 mW under a pump power of 5 W. By using the SESAM, the Q-switched mode locking and CW mode-locked operations are demonstrated.

Color centers and charge state recharge in gamma-irradiated Yb : YAP

Gamma-ray irradiation induced color centers and charge state recharge of impurity and doped ion in 10 at.% Yb:YAP have been studied. The change in the additional absorption (AA) spectra is mainly related to the charge exchange of the impurity Fe2+, Fe3+ and Yb3+ ions. Two impurity color center bands at 255 and 313 nm were attributed to Fe3+ and Fe2+ ions, respectively. The broad AA band centered at 385 nm may be associated with the cation vacancies and F-type center. The transition Yb3+ -> Yb2+ takes place in the process of gamma-irradiation. Oxygen annealing and gamma-ray irradiation lead to an opposite effect on the absorption properties of the Yb:YAP crystal. In the air annealing process, the transition Fe2+ -> Fe3+ and Yb2+ -> Yb3+ take place and the color centers responsible for the 385 nm band was destroyed. (c) 2005 Elsevier B.V. All rights reserved.

Color centers in Yb : YAG crystals grown by temperature-gradient techniques

Yb: YAG (Yb: Y3Al5O12) crystals have been grown by temperature-gradient techniques (TGT) and their color centers and impurity defects were investigated by means of gamma irradiations and thermal treatment. Two color centers located at 255 and 290 nm were observed in the as-grown TGT-Yb: YAG. Analysis shows that the 255 nm band may be associated with Fe3+ ions. Absorption intensity changes of the 290 nm band after gamma irradiation and thermal treatment indicate that this band may be associated with oxygen-vacancy defects. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

不同Yb掺质浓度的Yb：Y3Al5O12晶体激光性能的比较

采用提拉法生长了Yb^3＋掺质浓度为5％原子分数、50％原子分数和100％原子分数的Yb：Y3Al5O12（Yb：YAG）晶体。系统地分析了不同Yb^3＋掺质浓度晶体的吸收光谱和荧光光谱。从吸收峰和吸收系数可以看出采用940nm LD泵浦三种不同浓度的Yb：YAG晶体都比较合适。随着Yb^3＋离子掺质浓度的增高，晶体中出现的自吸收现象越为明显。通过对三种不同Yb掺质浓度晶体激光性能参数的计算，得出高掺质浓度Yb：YAG和YbAG晶体是有前景的激光增益介质。

半导体激光器抽运新型高效、调谐Yb：LYSO激光器

报道了以掺Yb介质硅酸镥钇晶体为增益介质的激光行为。在自由运转的条件下，在1086nm的中心波长处用2．5％的输出耦合镜得到7．8W的连续激光输出，相应的斜效率为64％。利用SF14棱镜作为腔内调谐元件，激光输出的调谐范围为1014-1091nm。

半导体激光器抽运新型Yb：GYSO混晶实现连续锁模激光输出

掺杂Yb^2＋离子的激光材料具有能级结构简单、抽运波长与振荡波长相近、量子效率高等优点，十分适合作为半导体激光器（LD）直接抽运的高功率激光光源。近年来，随着高性能InGaAs激光二极管的发展和成本的降低，掺Yb抖激光介质的研究受到人们的极大关注，并已研制出了许多新型激光晶体，如Yb：YAG，Yb：KYW，Yb：KGW，Yb：YAB，Yb：GGG和Yb：CaF2等。但是这些晶体还有很多不足之处，譬如生长比较困难、发射谱带相对窄和晶伙执导忡能相对姜等．

激光二极管抽运的高效率低阈值Yb：GSO激光器

近年来，掺Yb离子的晶体备受关注：掺Yb离子晶体能级结构简单，可以避免激发态再吸收、频率上转换、弛豫振荡和浓度猝灭等效应。此外，掺Yb离子晶体的吸收光谱位于900～1000nm，无需严格的温度控制即可与InGaAs激光二极管有效耦合，并且具有很宽范围的荧光发射谱，因此这种晶体很有潜力成为1gm波段的宽调谐及超快激光光源。

激光二极管抽运的Yb：GSO连续锁模激光

作为发射在1μm波段的二极管抽运全固态激光器的增益介质，掺Yb离子的晶体备受关注。掺Yb晶体具有能级结构简单，量子缺陷低（〈0．1），量子效率高等优点。目前成功使用掺Yb的晶体作为增益介质的飞秒激光振荡器已有很多报道，如Yb：BOYSE，Yb：KYW，Yb：SYSE等。

激光二极管抽运的Yb：GSO飞秒激光器

作为1μm附近由激光二极管直接抽运的高效、紧凑固体激光器的增益介质，掺Yb^3＋离子的激光材料越来越受到人们的关注。掺Yb的晶体具有能级结构简单，荧光寿命长，量子缺陷低等优点。掺Yb离子的激光晶体作为增益介质的飞秒激光振荡器国际上已有报道，实现全固态飞秒激光器件的实用化是国内外科学家追求的目标。

半导体可饱和吸收镜调Q的Yb：LSO激光器

报道了一个激光二极管（LD）抽运多波长连续输出的激光器和一个被动调Q的固体激光器。该激光器的增益材料是一种新型掺Yb^3＋的晶体Yb^3＋：Lu2SiO5（Yb^1LSO）。当吸收的抽运功率为2．57W时，连续输出的最大功率为490mW，斜率效率为22．2％，光-光转换效率为14．2％，激光阈值为299mW，输出激光波长为1084nm。多波长输出时，波长调谐范围为1034～1085nm。利用InGaAs可饱和吸收镜实现调Q输出时，斜率效率为3．0％，激光波长为1058nm。脉冲重复频率为25～39kHz，

Cr,Yb:YAG晶体的自调Q激光性能

用光纤耦合激光二极管抽运Cr,Yb:YAG晶体获得了1.03 μm的自调Q激光输出,输出的调Q脉冲非常稳定,抽运阈值功率为680 mW,脉冲宽度为3.3 ns,获得的平均功率为156 mW,斜率效率为18.5%。随着抽运功率的增大,重复频率成线性增长,而脉宽略有减少,单脉冲能量和峰值功率都始终呈增大趋势。光束质量因子M2为1.17。

Defect analysis in Czochralski-grown Yb : FAP crystal

Growth-induced defects in Yb:FAP crystals grown by the Czochralski method have been investigated by optical microscopy, chemical etching, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Anisotropic etching features have been observed on two FAP crystal planes: (0001) and (1010). The shape of etch pits on the (0001) plane is hexagonal, while the etch pits on the (1010) plane have a variety of irregular shapes. It is also found that the density of etch pit varies along the boule. Based on the experimental observations, the formation mechanisnis of growth defects are discussed, and methods for reducing the growth-induced defect concentration is proposed. (c) 2005 Elsevier B.V. All rights reserved.

Yb：FAP晶体的生长及光谱性能

应用中频感应提拉法生长出不同掺杂浓度的Yb：FAP激光晶体，运用电感耦合等离子体原子发射光谱仪（ICP-AES）测定了Yb^3＋离子存Yb：FAP晶体中的分凝系数约为0．03。随着晶体的生长，晶体中Yb^3＋离子的轴向浓度逐渐增大。研究Yb：FAP晶体在77K和300K温度下的吸收光谱发现，振动谱的变化主要是由电子-声子近共振耦合作用引起的。系统地研究了不同Yb^3＋离子掺杂浓度Yb：FAP晶体的吸收光谱和荧光光谱。通过吸收光谱的测量计算了晶体的吸收截面。Yb：FAP晶体在904nm和982nm处存在Yb