Suppressing the preferential o-polarization oscillation in a high power Nd：YVO4 laser with wedge laser crystal

We observe the phenomenon of priority oscillation of the unexpected a-polarization in high-power Nd：YVO4 ring laser. The severe thermal lens of the a-polarized lasing, compared with the n-polarized lasing, is the only reason for the phenomenon. By designing a wedge Nd：YVO4 crystal as the gain medium, the unexpected a-polarization is completely suppressed in the entire range of pump powers, and the polarization stability of the expected zc-polarized output is enhanced. With the output power increasing from threshold to the maximum power, no a-polarization lasing is observed. As a result, 25.3 W of stable single-frequency laser output at 532 nm is experimentally demonstrated.     

Nd:YVO4-KTP环形倍频激光器中KTP晶体温度与倍频输出波长关系的研究

采用Nd：YVO4-KTP环形倍频激光器,在精确控制泵浦源电流与YVO4晶体温度的条件下,得到KTP的温度变化与倍频输出波长的关系。     

激光二极管泵浦Nd∶YVO4/YVO4复合晶体绿光激光器

采用一种新型的Nd∶YVO4/YVO4复合晶体,利用V型折叠腔,研究了高功率激光二极管端面泵浦的Nd∶YVO4/YVO4复合晶体激光器基频1.06 μm及倍频532 nm激光的输出特性.当泵浦功率为24.6 W时,获得1.06 pm激光的最大输出功率为11.7 W,光-光转换效率为48%.当泵浦功率为17 W时,获得了5.32 W的绿光输出,光-光转换效率达到31.3%.     

激光二极管泵浦Nd:YVO4/YVO4复合晶体绿光激光器

采用一种新型的Nd:YVO4/YVO4复合晶体,利用V型折叠腔,研究了高功率激光二极管端面泵浦的Nd:YVO4/YVO4复合晶体激光器基频1.06 μm及倍频532 nm激光的输出特性.当泵浦功率为24.6 W时,获得1.06 μm激光的最大输出功率为11.7 W,光-光转换效率为48%.当泵浦功率为17 W时,获得了5.32 W的绿光输出,光-光转换效率达到31.3%.     

LD抽运的折叠腔Nd∶YVO4/KTP倍频红光激光器

对LD端面抽运的Nd∶YVO₄/KTP腔内倍频激光器的三镜折叠腔结构进行优化设计,研究了总腔长、输入镜曲率半径和Nd∶YVO₄和KTP晶体的热效应对激光谐振腔的稳定区域、Nd∶YVO₄晶体内基模光束半径的影响。实验结果表明:该方法所得出的结论与理论相吻合。在实验中比较了折叠腔不同折叠角度的红光输出功率,并获得了最佳折叠角度为25°,其有效倍频效率为10.8%。最后使用基频光的偏振特性与KTP的相位匹配之间的关系对实验结果进行理论解释。     

Efficient and high-power laser-diode single-end-pumped Nd：YVO4 continuous wave laser at 1342nm

A compact, efficient and high-power laser diode （LD） single-end-pumped Nd：YVO4 laser with continuous-wave emission at 1342 nm is reported. With a single crystal single-end-pumped by fibre-coupled LD array, an output power of 7.36W is obtained from the laser cavity of concave-convex shape, corresponding to an optical-to-optical efficiency of 32.8%. The laser is operated in TEM00 mode with small rms amplitude noise of 0.3%. The influences of the Nd concentration, transmissivity of the output mirror and the cavity length on the output power have been studied experimentally.     

YVO4晶体及其掺Nd的喇曼光谱

本文报道了对YVO4晶体及其掺Nd的喇曼光谱的测量结果,用这些结果可以了解到这种材料的声子能谱情况,在与其它基质材料比较中可以看出它的特点是：分立的低声子在500－800cm^-1之间有一个间隙,主要部分分布在800－900cm^-1附近,根据群论分析可以得出各喇曼谱线相应的对称性,而且可看出这些喇曼谱线主要来源于VO4^3-的振动,对这种不均匀分布的声子能变对于其光谱性能可能产生的影响也作了分析讨论,测量结果还发现掺杂能抑制原有的高能声子。     

高稳定LD泵浦腔内倍频Nd∶YVO4/KTP连续绿光激光器

设计出一种能够较好地补偿激光晶体热效应的激光谐振腔,实现了高稳定LD单端泵浦KTP腔内倍频Nd∶YVO4连续绿光激光器·当晶体吸收的泵浦功率为24.56W时,532nm激光功率达到5.3W,光-光转换效率达到21.6%,激光模式为TEM00模·在输出功率5W左右时,激光器1h功率不稳定度优于0.6%·     

Sixth Harmonic of A Nd：YVO4 Laser Generation In KBBF for ARPES

We report that a deep ultraviolet （DUV） laser from the sixth harmonic of a 1064nm laser has been firstly used as light source in an ultrahigh energy-resolution angle-resolved photoemission spectroscopy （ARPES）. The wavelength is 177.3nm obtained by using the second harmonic KBe2BO3F2 crystal with a frequency tripled 1064nm Nd：YVO4 laser. The large flux （10^14 - 10^15 photons/s） and narrow line width （0.26 meV） are suitable for the ultrahigh-energy resolution ARPES. The laser-ARPES can be a powerful tool to study the electronic structure at and near the Fermi level of the superconductor and correlated materials. The laser-ARPES has worked more than 500 h already.     

A Laser-Diode-Pumped 7.36 W Continuous-Wave Nd：YVO4 Laser At 1342 nm

An efficient and high-power diode-laser single-end-pumped Nd：YVO4 laser with cw emission at 1342nm is presented. With a crystal single-end-pumped by a fibre-coupled diode laser, an output power of 7.36 W is obtained from the laser cavity of concave-convex, eorresponding to an optical-to-optical conversion efficiency of 32.8%. The laser is operated in TEM00 mode with small rms noise amplitude of 0.3%. This represents, to the best of our knowledge, the highest power obtained from a diode-laser single-end-pumped Nd：YVO4 cw laser at 1342nm 80 far.     

高功率Nd∶YVO4/KTP腔内倍频晶体温度分布的半解析热分析

非线性晶体KTP采用Ⅱ类相位匹配腔内倍频时,不仅要求晶体满足基频光的偏振匹配条件,而且所选用的晶体要求符合λ/2波片的条件,才能使晶体的谐波转换效率达到最佳.由于倍频晶体吸收基频光能量引起晶体内部非均匀温升,改变晶体内部各点的折射率,也会使晶体产生不应有的热形变,破坏晶体初始的位相匹配条件,严重影响输出激光的品质和倍频效率.减弱、改善这种情况的关键是准确得出在实际工作条件下晶体内部温度场.利用半解析热分析方法得出了KTP晶体内部温度场的计算方法,分析了各种热参量变化对KTP晶体内部温度场的影响.得出的结果具有一定的普适性,可以应用到具有轴对称形式内热源的其它热模型温度场的计算分析中,对连续波腔内倍频激光系统的设计将起到指导作用.     

激光二极管端面抽运的1.34μm Nd:YVO4平凹腔型激光器

理论上分析了端面抽运的1.34μm Nd:YVO4平凹腔型激光器的各项参数;实验上实现了LD端面抽运的1.34μm Nd:YVO4平凹腔型激光器的运转.     

Simulation of Patterns and Qualitative Analysis of Pattern Rotation in an End-Pumped Nd：YVO4 Laser

We simulate some laser output patterns observed in our previous experiment employing superposition of Laguerre- Gaussian modes. The rotating pattern is qualitatively analysed from the point of contemporary spatial burning hole effect of the lasing crystal.     

Comparison between Two Kinds of Semiconductor Absorbers for Mode-Locking in Nd：YVO4 Laser

We have demonstrated passive mode-locking in a diode-end-pumped Nd：YV04 laser using two kinds of semiconductor absorbers whose relaxation region comes from Ino.2sGao.75As grown at low temperature （LT） and GaAs/air interface respectively. Mode-locking, using absorbers of the GaAs/air interface relaxation region, has the characteristics of less Q-switching tendency and higher average output power than that using absorbers of LT In0.25Ga0.75As relaxation region, but is not as stable as the latter.     

激光二极管抽运的高输出单频稳频Nd∶YVO4激光器

研制了光纤耦合的激光二极管抽运的单频稳频Nd∶YVO4激光器。在输入抽运功率为 6W的情况下 ,获得 2W稳定单频红外输出 ,光光转换效率为 33 3% ,电光转换效率为 10 %。通过边带稳频系统将输出激光频率锁定在法布里珀罗共焦参考腔的中心频率上 ,频率稳定性优于 40 0kHz     

激光二极管抽运的高输出单频稳频Nd：YVO4激光器

研制了光纤耦合的激光二极管抽运的单频稳频Nd:YVO4激光器。在输入抽运动率为6W的情况下,获得2W稳定单频红外输出,光－光转换效率为33．3％,电－光转换效率为10％。通过边带稳频系统将输出激光锁定在法布里－珀罗共焦参考腔的中心频率上,频率稳定性优于400kHz。     

大功率LD抽运的Cr^4＋：YAG被动调Q Nd：YVO4激光器

在LD端面抽运的Nd：YVO4激光器中插入Cr^4＋：YAG晶体,获得了稳定的1．06μm波长的高重复率被动调Q脉冲激光输出。实验研究了抽运功率、腔长、输出镜透过率对输出功率的影响,以及不同抽运功率下脉冲重复频率和脉冲宽度的变化,并对结果进行了理论分析。当腔长为8cm,抽运功率为27W时,得到重复率37．8kHz、平均功率3．5W的调Q脉冲序列;单个脉冲能量为93μJ、脉宽为24ns、峰值功率为3．9kW。     

Laser diode end-pumped Nd：YVO4 regenerative amplifier for picosecond pulses

A diode dual-end-pumped Nd:YVO4 regenerative amplifier is reported. The influence of the cavity stability on the performance of the regenerative amplifier is studied. The experimental results match well with the analysis at high pump power. The mode locking seed pulses with 15 ps pulse width and 10 nJ single pulse energy at 86 MHz are amplified up to 4.7 mJ at 1 kHz, corresponding to the maximum amplification about 0.5 × 106 , by our regenerative amplifier. And an average power of 4.7 W is obtained at the repetition rate from 1 kHz to 10 kHz.