共查询到20条相似文献,搜索用时 682 毫秒
1.
The absorption and fluorescence spectra of Cr,Yb:YAG crystal were measured. There are two absorption bands at 940 nm and 968 nm although the absorption coefficient is lower than that of the absorption peak of Yb:YAG superimposed in Cr:YAG absorption peak. The emission peak intensity is 4 times lower than that of Yb:YAG, which may be caused by the existence of the ground state absorption of Cr4+ which quenches the Yb3+ emission intensity. Although the emission peak of Cr,Yb:YAG is lower than that of Yb:YAG, there is an advantage of this crystal which combines the saturable absorber and gain medium into one and can be a self-Q switching laser crystal if Cr,Yb:YAG crystal is pumped with high energy power. 相似文献
2.
3.
1lntroductionThsaturableabsotherswhichhavebeensucceSSfullyusedforpassiveQswitched1asersincludedye['],Lffi:F2colDcenterCrytals['],Cr -doPedcrysds['~'],etc.Amngthem,Cr -doPedCryStalsdevtheedinrecentyearssuchasCr :YAG,Cr :GSGG,andCr :WeSnyandsoon,havetheadVanageSofgoodphoto-chedcalandthermalstabillty,largabsorptbocross-section,besaturableintensityandhighdaInaethreshod.Inaddition,Cr canbedoPedintOgainmediumtoformselfQ-switchedl..,['J.Cr -dopedcrystalsbecomethemostprotalsingsatIJrable… 相似文献
4.
The absorption spectra characters of the (Cr,Yb):YAG,Cr:YAG and Yb:YAG crystals are reported. In the absorption spectra of the (Cr,Yb): YAG crystal,there are two absorption bands at 937 nm and 968 nm respectively,which are suitable for InGaAs diode laser pumping;and there is an absorption band of Cr4+ near 1030 nm,which is suitable for passive Q switch laser output at 1.03 μm. This Cr-Yb-codoped crystal may be a potential material for compact,diode laser pumped passive Q-switched solid-state laser with efficient,high-stable. 相似文献
5.
6.
Yb:YAG晶体的光谱性能 总被引:10,自引:0,他引:10
系统地研究了不同掺杂浓度的Yb:YAG晶体的光谱特性,通过吸收光谱的测量计算了晶体的吸收截面,用对易法计算了晶体的发射截面。在Yb:YAG晶体毛坯中发现Yb^2+和色心,其浓度随Yb:YAG晶体中Yb^3+的增加而增加。经1400℃氧气氛退火后消失。首次用光子激发和X射线激发研究了Yb:YAG晶体的荧光特性。 相似文献
7.
制备了纯的、掺0.005、0.01、0.2和0.5wt%Cr2O3的钛酸锶单晶.测量了不同退火条件下的室温透射光谱及6.5K以上的荧光光谱.对晶体的氧化和还原热处理诱导吸收及退火和掺杂浓度对晶体发光的影响进行了较为详细的研究. 相似文献
8.
Influence of Gamma-Ray Irradiation on Absorption and Fluorescent Spectra of Nd:YAG and Yb:YAG Laser Crystals 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We investigate the influence of gamma-ray irradiation on the absorption and fluorescent spectra of Nd^3+:Y3A15 O12 (Nd: YAG) and Yb^3+ : Y3A15 O12 (Yb: YAG) crystals grown by the Czochralski method. Two additional absorption (AA) bands induced by gamma-ray irradiation appear at 255nm and 340nm. The former is contributed due to Fe^3+ impurity, the latter is due to Fe^2+ ions and F-type colour centres. The intensity of the excitation and emission spectra as well as the fluorescent lifetime of Nd:YAG crystal decrease after the irradiation of 100 Mrad gamma-ray. In contrast, the same dose irradiation does not impair the fluorescent properties of Yb:YAG crystal. These results indicate that Yb: YA G crystal possesses the advantage over Nd: YA G crystal that has better reliability for applications in harsh radiant environment. 相似文献
9.
The Yb:YAG and Yb:YAP crystals have been grown by Czochralski method. The absorption spectra and the fluorescence spectra of Yb:YAG and Yb:YAP crystals have been investigated. It is shown that the Yb:YAG crystal has better laser properties and smaller threshold power than Yb:YAP crystal. In addition, the absorption cross-section of the Yb:YAP crystal is 2.16 times of that of the Yb:YAG crystal,so laser diode pumped Yb:YAG lasing can be easily realized. Because YAP single crystal is anisotropic, it is provided with polarization characteristics. 相似文献
10.
Yb3+离子掺杂浓度对Yb∶YAG晶体发光及荧光寿命的影响 总被引:3,自引:3,他引:0
研究了不同掺杂浓度Yb∶YAG晶体的发光特性和荧光寿命.Yb3+在YAG晶体中的掺杂浓度分别为5at%、10at%、20at%、30at%.Yb3+离子掺杂浓度越高,Yb∶YAG晶体的吸收系数越大.采用940 nm波长的LD泵浦源和TRIA X550荧光谱仪,对这一系列掺有不同浓度Yb3+的Yb∶YAG晶体进行了荧光光谱的测定.结果表明:在1030 nm主发光波段的荧光强度以10at%Yb∶YAG的为最强.同时发现它在450 nm-680 nm波段有明显的可见发光,其强度随Yb3+掺杂浓度的增加而迅速地增强.Yb∶YAG晶体的荧光寿命存在浓度猝灭现象,对猝灭机制进行了分析研究,指出浓度猝灭的主要原因是合作发光和痕量稀土离子的上转换发光. 相似文献
11.
12.
The emission and the lifetime data of Cr, Yb: YAG and Yb: YAG were reported. The effective peak stimulated-emission cross section of chromium and ytterbium-co-doped yttrium-aluminum garnets (Cr, Yb: YAG) has been determined to be 8.98 × 10-20 cm2 at room temperature. The luminescence spectrum of Cr, Yb: YAG is the same as that of Yb: YAG. The luminescence lifetime of Cr, Yb: YAG at room temperature is 0.3 ms (Yb: YAG, 1.48 ms ). The causes of the differences in the fluorescence spectra and the stimulated emission cross-section between Yb: YAG and Cr, Yb: YAG crystals were discussed. Also the potential of Cr, Yb: YAG as a self Q- switched laser crystal was discussed. 相似文献
13.
Investigation of the Emission Cross-sections and the Spectra of (Cr~(4 ), Yb~(3 ) ): YAG Crystal 总被引:2,自引:0,他引:2
l introductionIn recent years, Cr4 --doped crystals have attracted a great deal of attention aspassive Q--,wit,h.,[l~4]. These Cr4 --dOPed crystals include Cr4 : YAG[l'21 ) Cr4 :GSGG[s], Cr4 : YSO['] etc. They have a large absorption cross section and lOwsaturable intensity at the laser wavelength. In comparison with previously usedsaturable absorbers such as dyes['] and LiF: FZ-- [6] cOlor center crystals, Cr4 -dopedcrystals are more photO--chemically and thermally stable and h… 相似文献
14.
Laser crystal Yb3+-doped NaY(WO4)2 (Yb:NYW) with excellent quality has been grown by Czochralski technique. The rocking curves from (400) plane of as-grown
Yb:NYW crystal was measured and the full-width value at half-maximum was 19.92″. The effective segregation coefficients were
measured by the X-ray fluorescence method. The polarized absorption spectra and the fluorescence spectra of Yb:NYW crystal
were measured at room temperature. The fluorescence decay lifetime of Yb3+ ion in NYW crystal has been investigated. The spectroscopic parameters of Yb:NYW crystal are calculated and compared with
those of Yb:YAG crystal. A continuous wave output power of 3.06 W at 1031 nm was obtained with a slope efficiency of 42% by
use of diode pumping. 相似文献
15.
Y. Cheng X. B. Yang Z. Xin S. S. Cheng D. H. Cao X. D. Xu J. Xu 《Laser Physics》2009,19(12):2168-2173
Yb3+-doped NaGd(WO4)2 (Yb:NGW) crystal has been successfully grown by Czochralski method. The rocking curves from (400) plane of as-grown Yb:NGW
crystal was measured and the full-width values at half-maximum was 21″. The polarized absorption spectra, the fluorescence
spectra and the fluorescence decay lifetime of Yb:NGW crystal were measured at room temperature. The spectroscopic parameters
of Yb:NGW crystal are calculated and compared, with those of Yb:YAG crystal. A continuous wave output power of 3.01 W at 1048
nm was obtained with a slope efficiency of 71% by use of diode pumping. 相似文献
16.
Optical properties of Cr,Yb:YAG, Cr,Nd:YAG crystals, and composite Yb:YAG/Cr:YAG ceramics self-Q-switched solid-state laser
materials are presented. The merits of these self-Q-switched laser materials are given and the potentials of such lasers can
be chosen by the applications. Cr,Yb:YAG and composite Yb:YAG/Cr:YAG ceramics self-Q-switched laser are conducted. Although
several tens of kW peak power can be obtained with a monolithic microchip Cr,Yb:YAG laser, the experimental results show that
the performance of this laser is limited by the absorption of Cr4+ ions at a pump wavelength of 940 nm and strong fluorescence quenching at high Cr concentration. Composite Yb:YAG/Cr:YAG ceramics
are more suitable to realize high pulse energy and peak power (up to MW level) with optimized lasing and Q-switching parts.
In addition, the instabilities induced by the multi-longitudinal mode competition in Cr,Nd:YAG and Cr,Yb:YAG microchip lasers
are addressed. The different gain bandwidths of Yb:YAG and Nd:YAG play an important role in the instability of the output
laser pulse trains. Stable laser pulses from the Cr,Yb:YAG microchip laser were obtained due to the antiphase dynamics. For
the Cr,Nd:YAG microchip laser, the instability caused by the multi-longitudinal mode competition is an intrinsic property.
Different transverse patterns were observed in Cr,Nd:YAG microchip lasers when a pump beam with larger diameter was used.
Saturated inversion population distribution inside the gain medium plays an important role in the transverse pattern formation.
Different transverse patterns were reconstructed by combining different sets of the Hermite-Gaussian modes. 相似文献
17.
A high-quality Cr 3+:CdWO4 single crystal at a size of approximatelyΦ25×80 mm is grown using the Bridgman method with CdO,WO3,and Cr2O3 as raw materials and their molar ratio of 100:100:0.5.The temperature gradient of solid-liquid interface at growth is approximately 50?C/cm and the growth rate is 0.05 mm/h.The X-ray diffraction(XRD),absorption,excitation,and emission spectra of different parts of the as-grown and O2-annealed crystals are investigated.Two strong broad optical absorption bands of about 472 and 708 nm are observed,and they are associated with the transitions 4 A2→ 4 T1 and 4 A2→ 4 T2.The weak 4 T2→ 2 E transition(the R-line)at 632 nm is also observed.The crystal-field parameter Dq and the Racah parameters B and C are estimated to be 1 412.4,776.8,and 3 427.6 cm? 1,respectively,according to the absorption spectra and crystal-splitting theory.A broadband fluorescence at about 1 000 nm due to 4 T2→ 4 A2 transition is produced by exciting the samples at 675 nm.After being annealed in an O2 atmosphere,the crystals become more transparent,while the effective light absorption of Cr 3+ ions is evidently enhanced and the emission intensity is also strengthened due to the reduction of oxygen vacancies in the CdWO4 crystal after annealing. 相似文献
18.
Yb :YAG晶体的闪烁特性 总被引:1,自引:0,他引:1
通过不同Yb3+掺杂浓度(5%~30%,原子数分数)的Yb:YAG晶体的阴极射线发光谱、衰减时间、光输出及其温度依赖关系的测量,研究了Yb:YAG晶体的闪烁性能.不同Yb3+掺杂浓度的Yb:YAG晶体具有不同的光输出和猝灭温度,光输出随Yb3+掺杂浓度的增大而降低,猝灭温度则随掺杂浓度的增大而升高.室温下Yb:YAG晶体的发光衰减时间较短,均小于50ns.Yb3+掺杂浓度为5%的Yb:YAG晶体具有较高的光输出和较低的猝灭温度. 相似文献
19.
采用提拉法生长Y3A15O12(YAG)晶体和Yb^3+掺杂原子数分数分别为5%,10%,15%,20%,25%,50%N100%的Yb:Y3A15O12(Yb:YAG)晶体。系统表征和分析了Yb^3+掺杂浓度对拉曼光谱的影响。随着Yb^3+掺杂浓度的增加,晶体的振动模式没有明显的变化,晶体结构没有改变;在370cm^-1和785cm^-1附近,振动吸收峰的半峰全宽逐渐增大。分析得出,Yb抖掺杂浓度对晶体的晶格、对称性、荧光寿命均有影响,从而可能影响到晶体的光谱和激光性能。 相似文献
20.
YAG晶体中Cr~(3+)→Tm~(3+),Er~(3+)→Tm~(3+)的能量 总被引:1,自引:1,他引:0
研究了加入敏化离子Cr3+和Er3+的Tm:YAG晶体的吸收谱和荧光谱,计算了Cr3+、Er3+、Tm3+离子的2E、4I13/2、3F4能态的平均寿命及能量;转移效率、转移速率.得出Cr3+→Tm3+转移效率为80%,转移速率为2.1×103s-1.由(Er,Tm):YAG的荧光谱可见存在Er3+→Tm3+的有效的能量转移.讨论了Cr3+→Tm3+和Er3+→Tm3+能量转移的不同. 相似文献