Effect of Nd3+ Concentration on the Laser Performance of a New Laser Crystal∶Nd∶NaY(WO4)2

The transmission and emission spectra of a new crystal, Nd∶NaY(WO4)2 (Nd∶NYW) have been measured. Using a Ti∶Sapphire laser as the pump source, the laser performances of Nd:NYW crystals with different concentrations are compared for the first time. The Nd3+ concentrations used are 1, 2, 4 and 5 at.-%. The experiments show that 2 at.-% is the optimum concentration. When the incident pump power is 575 mW, the 1.06 μm output can reach 184 mW, corresponding to an optical to optical efficiency of 32%. The experimental results show that the work is significant to the further research and praction application of this promising laser crystal.     

Effect of Nd concentration on the laser performance of a new laser crystal: Nd : NaY(WO4)2

We have measured the transmission and emission spectra of a new crystal, Nd : NaY(WO₄)₂ (Nd : NYW). Using a Ti : sapphire laser as the pump source, the laser performances of Nd : NYW crystals with different concentrations are compared for the first time. The Nd³⁺ concentrations used are 1, 2, 4 and 5 at%. Our investigation shows that 2 at% is the optimum concentration. When the incident pump power is 575 mW, the 1.06 μm output can reach 184 mW, corresponding to an optical-to-optical efficiency of 32%. We believe that our work is significant for the further research and actual application of this promising laser crystal.     

Nd∶NaR(WO_4)_2晶体生长(R=Bi,Y)

采用提拉法生长出了掺钕钨酸铋钠[Nd∶NaBi(WO4)2,简称Nd∶NBW]和掺钕钨酸钇钠[Nd∶NaY(WO4)2,简称Nd∶NYW]晶体,并给出了制备无开裂优质Nd∶NBW和Nd∶NYW晶体的最佳生长工艺参数。从XRD分析得到Nd∶NBW和Nd∶NYW晶体的晶胞参数,并分析了晶体的拉曼光谱,认为二者结构基本相同,为四方晶系、白钨矿结构、I41/a空间群。由吸收光谱可以看出,Nd∶NBW在802nm有较强的吸收峰,Nd∶NYW在804nm、752nm、586nm附近有较强、较宽的吸收峰,二者均适合于LD泵浦;计算了晶体中Nd3+的吸收截面积。     

Passive Q-switching of a laser-diode-pumped intracavity-frequency-doubling Nd:Nd<Superscript>3+</Superscript>:NaY(WO<Subscript>4</Subscript>)<Subscript>2</Subscript>/KTP laser with Cr<Superscript>4+</Superscript>:YAG saturable absorber

Nd³⁺:NaY(WO₄)₂, known as Nd:NYW, is a new type crystal. By using laser-diode as pump source, a passive Q-switching of intracavity-frequency-doubling Nd:NYW/KTP laser has been realized with Cr⁴⁺:YAG saturable absorber. The dependence of pulse repetition rate, pulse energy, pulse width, and peak power on incident pump power for different small-signal transmissions of Cr⁴⁺:YAG are measured. The coupled rate equations are used to simulate the Q-switched process of laser, and the numerical solutions agree with the experimental results.     

激光二极管端泵微片固体激光器的研究

本文介绍了一种用波长为809nm的激光二极管(LD)端面泵浦厚度为1mm的微片Nd:YVO4全固化固体激光器。器件结构上采用了一种独特的光学系统,该系统由分别用于LD激光束的耦合和聚焦的两部分组成。由Nd:YVO4的一个平面与一个曲率半径为21mm的球面镜组成半共焦腔,以获得高的转换效率。文中详细讨论了单横模运转时的泵浦光与激光腔模之间的匹配问题。当泵浦光功率为400mW时,获得152mW的1064nm波长的TEM00模激光输出。器件阈值功率为48.3mW,总的光-光转换效率为38%,斜效率为43%.     

Laser–diode-pumped passively Q-switched Nd:NaY(WO4)2 laser with GaAs saturable absorber

A laser–diode-pumped passively Q-switched new type crystal Nd³⁺:NaY(WO₄)₂ (known as Nd:NYW) laser with GaAs semiconductor saturable absorber has been realized. The dependence of pulse repetition rate, pulse energy, pulse width, and peak power on pump power for different output coupler reflectivities are measured. The coupled rate equations are used to simulate the Q-switched process of laser, and the numerical solutions agree with the experimental results.     

Characteristics of a passively Q-switched Nd:NaY(WO4)2 laser with Cr:YAG saturable absorber

By using xenon flash lamp as pump source and Cr⁴⁺:YAG as passive Q-switcher, we have performed the Q-switched laser operation at 1.06 μm with an Nd³⁺:NaY(WO₄)₂ (known as Nd:NYW) crystal. Meanwhile, the pulse width, the single pulse energy and the repetition rate under different small-signal transmissions of Cr⁴⁺:YAG and different reflectivities of output reflector are measured, and the numerical solutions of the coupling wave rate equations agree with the experimental results.     

New green self-frequency-doubling diode-pumped Nd:Ca4GdO(BO3)3 laser

3+ :Ca₄GdO(BO₃)₃ (Nd:GdCOB). 21 mW of green cw laser emission for an absorbed pump power of 820 mW were achieved under laser diode-pumping. 64 mW of green cw laser output were obtained with 1 W of absorbed pump power under titanium-sapphire pumping. Its availability in large-size crystals with good optical quality makes Nd:GdCOB a true challenger to the best SFD laser crystal reported so far: Nd:YAl₃(BO₃)₄ (Nd:YAB or NYAB). Received: 2 March 1998/Revised version: 20 May 1998     

激光二极管直接耦合泵浦的高效率Nd：YVO4／KTP腔内倍频激光器

使激光二极管的发光光面紧贴Ｎｄ：ＹＶＯ４激光晶体，“面对面”直接耦合泵浦，采用ＫＴＰ晶体腔内倍频，在５０３ｍＷ的泵浦功率下，获得５３２ｎｍ基横模绿光输出约７３ｍＷ，光光总体转换效率为１４．５％。     

激光二极管端面抽运Nd:YVO4实现1386 nm连续波激光输出

在Nd:YVO4晶体的4F3/2-4I13/2跃迁带内,除了1342 nm激光辐射之外,其它的跃迁谱线由于小的受激发射截面和强的寄生振荡,很难形成激光振荡.通过调整谐振腔损耗,获得了光纤耦合激光二极管端面抽运1386 nmNd:YVO4激光器激光连续输出.在抽运功率达到4.24 W时,得到了305 mW的1386 nm激光连续输出,最高输出功率下的斜效率为13.9%.实验中还观察到了1342 nm和1386 nm的双波长运转.根据抽运阈值能量和实验数据,计算得到了Nd:YVO4晶体中1386 nm激光辐射处的受激发射截面大约为(3±1)×10-19cm2.     

Experimental Study on Flashlamp Pumped Nd3+:KGd(WO4)2 Laser

The lasing properties of Nd:KGW crystal in free-running mode with different transmission of the output couplers are reported. The best results have been obtained with the output coupler of 24% transmission. The slope efficiency is 1.0% and the extrapolated energy threshold is 0.54 J. A comparative experiment of Nd:KGW and Nd:YAG laser crystals has been cavried out under identical experimental conditions in both free-running and Q-switched modes. The much higher efficiency and the lower threshold for Nd:KGW (Nd: 2.2 at. -%) compared to Nd:YAG (Nd: 1.1 at. -%) at 1.064 μm are demonstrated in both operation mode.     

连续锁模Nd：YVO4激光器实现1 GHz高频输出

LD抽运全固体Nd:YVO4激光器在连续锁模状态运转下获得了高达1 GHz的重复频率.实验中采用半导体可饱和吸收镜作为锁模元件.利用透过率只有0.8%的输出镜以及可获得较小抽运光斑的2 W LD作为抽运源来优化激光器设计,有效地抑制了调Q锁模状态的运转.低的激光器振荡阈值（35 mW）和连续锁模阈值(0.8 W)显示了饱和吸收体低的插入损耗和激光器合理的设计.在最大抽运1.6 W时获得了210 mW的平均输出功率.     

LD抽运Nd:Gd1-xYxVO4连续波激光器的实验研究

报道了一种半导体二极管(LD)抽运Nd:Gd1-xYxVO4晶体,采用简单、结构紧凑的平-平腔设计,实现了1.06 μm连续波激光输出,在8 W的注入功率下,获得3.25 W的1.06 μm连续波激光输出,光-光转换效率为41%,斜效率为45%.KTP腔内倍频实现了稳定的连续波532 nm绿光激光运转,当注入功率为8 W时,单向获得了621 mW的单模绿光输出.     

Continuous-wave Nd:KGd(WO4)2 single-longitudinal-mode laser

A continuous-wave Nd:KGd(WO₄)₂ single-longitudinal-mode laser is demonstrated with Fabry-Perot etalons in a simple linear cavity. The thermal lens effect is dramatically lowered by propagating the laser beam along the ‘athermal’ direction inside the laser crystal, which is very beneficial to removing the heat generated in the mode selection process. The maximum single-longitudinal-mode output power obtained is 64.8 mW at incident pump power of 4.7 W, corresponding to an optical conversion efficiency of 1.3% and a slope efficiency of 1.7%.     

LD泵浦Nd:YAG/LBO结构660 nm红光激光器

采用国产LD泵浦Nd:YAG晶体,通过谐振腔镜的膜系选择获得了Nd³⁺离子中波长为1319 nm的受激辐射振荡,首次用I类临界位相匹配LBO进行腔内倍频,实现了660 nm红色激光的高效倍频输出.当泵浦注入功率为800 mW时,660 nm激光基横模(TEM₀₀)输出功率为46 mW,光光转换效率高达5.75%.     

二极管泵浦1064nm单频Nd∶YVO_4激光器的研究

报道了一种用国产激光二极管泵浦的1064nm单频Nd∶YVO4红外激光器的设计。利用布氏片和石英晶体组合构成的双折射滤光片技术,在泵浦功率为800mW时,实现了功率为360mW的1064nm红外单频输出。测量结果表明,偏振比超过了1000∶1,功率稳定性优于0 5%,振幅噪声小于0 1%。     

LD抽运Nd:LuVO4微片激光器性能研究

报道了一类新型的LD端面抽运Nd:LuVO4微片激光器,讨论了在不同掺杂浓度,不同厚度和不同透过率下的激光性质,测定了在不同抽运功率下,微片最佳激光输出功率与LD抽运温度的关系.在2W抽运功率下获得923mW的1064nm激光输出,阈值为48mW,斜效率为52%.对微片制冷后斜效率提高到59%.     

Analytical and Experimental Studies on Nd:YVO4/KTP Lasers Pumped by High-brightness Laser Diodes

We report analytical and experimental studies on the characteristics of a high-brightness laser diode endpumped Nd:YVO₄/KTP laser. A simple model was developed to optimize the cavity parameters and estimate the green output power of intracavity frequency doubled lasers. Using a 1 W high-brightness laser diode as the pump source, high efficiency operation was realized. The second-harmonic output power at 532 nm was measured to be 286.5 mW at an incident pump power of 881.4 mW, corresponding to an optical to optical efficiency of 32.5%.     

LD泵浦全固态608.1nm和频激光器

本文报道了一种全固态腔内和频608.1 nm激光器。在激光谐振腔两个分臂中,两支激光二极管分别泵浦Nd: YVO₄和Nd: YAG晶体,分别选择1 342 nm波长(Nd: YVO₄晶体的⁴F_3/2-⁴I_13/2谱线)与1 112 nm波长(Nd: YAG晶体的⁴F_3/2-⁴I_11/2谱线)振荡并进行腔内和频。通过优化谐振腔设计,腔内两个波长获得了较好的模式匹配。在两个分臂的交叠部分,利用LBO I类相位匹配进行和频,获得和频608.1 nm激光输出。实验表明,当Nd: YVO₄与Nd: YAG晶体泵浦功率分别为600和740 mW时,获得了功率为23.8 mW、波长为608.1 nm激光输出,激光输出稳定、噪声低。利用本文提出的和频结构是获得608.1 nm激光输出较为有效的方法。     

Efficient dual-wavelength operation of Nd:LYSO laser by diode pumping aimed toward the absorption peak

By aiming the pump wavelength of the laser diode to the absorption peak at 811 nm of the (Nd 0.005 Lu 0.4975 Y 0.4975 ) 2 SiO 5 (Nd:LYSO) crystal, an efficient dual-wavelength operation at 1 075 and 1 079 nm is obtained. The maximum output power is 702 mW when the incident pump power is 2.53 W, corresponding to an optical conversion efficiency of 27.7% and a slope efficiency of 37.0%