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

侧面抽运板条激光介质动态热畸变测量方法

研究了基于干涉测量激光介质热畸变的原理,利用CCD摄像机记录干涉条纹并通过计算机图像处理,来测量板条激光介质动态热畸变的方法。对采集得到的干涉条纹进行图像处理,提出了一种简单快速提取条纹中心的算法。通过分析、计算干涉条纹的移动,得到抽运过程中板条激光介质的动态热畸变情况,为动态补偿激光介质热效应提供了可能。实验采用了N31磷酸盐激光玻璃作样品,得到了加热过程中激光玻璃内部的温度分布,误差约为3%,验证了该测量方法的可行性。

Nd：Y3Sc（1．5）Al（3．5）O（12）透明陶瓷的光谱性能以及激光输出

采用燃烧法制备了Nd：YSAG粉体,经过成型、素烧,最终在氢气气氛中烧结制备了Nd：YSAG透明陶瓷.测试结果表明,Nd：YSAG透明陶瓷具有荧光谱线较宽,荧光寿命较长的特点.激光实验得到的激光输出,斜率效率为23.6%,输出功率为0.36W,输出激光的谱线分布较宽.

侧面抽运国产Nd∶YAG陶瓷棒的激光特性

实验研究了激光二极管阵列(LDA)侧向抽运国产Nd∶YAG陶瓷棒的准连续及被动调Q激光输出特性。该陶瓷激光器采用LDA侧面紧密环绕均匀排布的抽运结构,陶瓷棒抽运区域长度为20 mm,其总尺寸为3 mm×35 mm,掺杂原子数分数为~1%。在千赫兹准连续运转条件下,当平-平谐振腔的输出耦合镜透过率为47.3%时,获得最大平均功率23 W的1064 nm激光输出,光束发散角为4.5 mrad,斜率效率达12%。在谐振腔内插入Cr4+∶YAG晶体作为被动调Q开关,成功地实现了陶瓷激光器千赫兹重复频率调Q激光脉冲输出,当Cr4+∶YAG晶体初始透过率为60%时,输出激光脉冲宽度(半峰全宽)可窄至14.5 ns,调Q动静比约为40%。

高重复率窄脉宽Nd∶YVO_4板条激光器

部分端面抽运的混合腔板条激光器是一种新型的全固态激光器,采用这种结构,实现了高重复率调Q运转。在脉冲抽运情况下,1kHz运转时,得到脉宽4.6ns,单脉冲能量4.5mJ的激光输出。在连续抽运调Q输出情况下,5kHz高重复率运转时,获得了脉宽6ns,单脉冲能量3.1mJ的脉冲序列输出,平均功率超过15W;当重复率高达25kHz时,得到脉宽9.5ns,单脉冲能量1.2mJ的激光输出,平均功率达30W。实验结果表明,输出水平还有很大的提升空间。

传导冷却的全固态zigzag板条激光器

报道了激光二极管泵浦的被动传导冷却的Q开关Nd:YAG zigzag 板条激光器，谐振腔采用平平腔和非稳腔。在20Hz运转时，得到脉宽均为10ns的150 mJ，光光效率19%的多模输出和100 mJ、13%光学效率的单模输出，并进行了相关的热效应测试，结果表明该激光器具有效率高、结构紧凑、光束质量好，在空间环境应用具有很好的发展潜力。

双包层光纤侧面耦合器

研究了一种侧面抽运双包层光纤的方法，从被剥除了外包层、端面为350μm×400μm的D型双包层光纤内包层上切下长度为3mm的一段柱体，并胶合在相同的双包层光纤内包层的侧面上，构成了柱体-光纤侧面耦合器。半导体激光器的抽运光从该柱体的一端入射并通过它耦合进入双包层光纤的内包层，实验测得耦合器最大耦合效率为85％。该方法适用于输出功率为数瓦的光纤激光器和放大器的侧面抽运。

采用国产双包层光纤的声光调Q激光器

实验报道采用我国自行设计的大模场掺镱双包层光纤，利用简单声光调Q装置，成功实现调Q运转；在1－50kHz调制频率下获得了百纳秒的调Q脉冲，其输出光束质量因子大约为2。当重复频率为1kHz时，获得了脉冲宽度为132ns，能量0.93mJ。同时实验中观察到的调Q脉冲常出现一点锁模现象，针对这一现象进行了讨论。

大模场面积光纤激光器79．4W单横模输出

abstract {A large-mode-area (LMA) multimode fiber before and after coiling was studied contrastively in the experiment. Single-transverse-mode output was achieved when the fiber laser was coiled around a mandrel of 65 mm radius. After coiling, beam quality factor of the laser dropped from 1.24 to 1.06 and slope efficiency dropped from 64.7% to 54.3%. When the launched pump power was 149 W, the corresponding output power was 94.7 W and 79.4 W, respectively. However, the brightness of the coiled fiber laser was 1.15 times that of the uncoiled. Coiled modal losses of different modes were also calculated for the fiber employed in the experiment. The measured results agree well with the calculated ones.}

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.

Experimental study of Ti : sapphire laser end-pumped Nd : YAG ceramic laser Q-switched by Cr4+: YAG saturable absorber

By employing a continuous-wave (CW) Ti:sapphire tunable laser as a pumping source and a Cr4+:YAG single crystal as the saturable absorber (SA), a passively Q-switched Nd:YAG ceramic laser has been demonstrated at room temperature. With an absorbed pumping power of 541 mW at 808 nm, an average output power of 61 mW at 1064 nm has been obtained with 3.5 mu J pulse energy, 15 ns pulse width and 18.18 kHz repetition rate, and the corresponding slope-efficiency is 15%. The relationships between the pulse width, repetition rate, average output power, pulse energy, and peak power on the absorbed pumping power for different initial transmission of the Cr4+:YAG SA are discussed separately. The Nd:YAG ceramic is one of the most promising laser materials for compact, efficient, all-solid-state pulsed lasers.

The intensity distribution and thermal stability of InnoSlab laser

Partially end-pumped slab laser is an innovative solid state laser, namely InnoSlab. Combining the hybrid resonator with partially end-pumping, the output power can be scaled with high beam quality. In this paper, the output intensity distributions are simulated by coordinate transformation fast Fourier transform (FFT) algorithm, comparing the thermal lens influence. As the simulated curves showed, the output mode is still good when the thermal lens effect is strong, indicating the good thermal stability of InnoSlab laser. Such a new kind of laser can be designed and optimized on the base of this simulation.

High optical-optical efficiency of 52.5% obtained in high power Nd : YAG ceramic laser

Using a quite uniformly side-around arranged compact pumping system, a high power Nd:YAG ceramic quasi-CW laser has been demonstrated with high optical-to-optical conversion efficiency over 50% for the first time. With 450 W quasi-CW stacked laser diode bars pumping at 808 run. 236 W Output at 1064 run was obtained and no saturation phenomena were observed.

Nd-glass belt lasers with improved beam quality

Nd-doped phosphate glass belt lasers pumped by laser diodes are demonstrated. The Nd-glass belt with a large cross-section and a small Fresnel number is air-cooled to provide around 18-W continuous wave (CW) output power with a beam quality factor of My2

Nd : YAG ceramic laser obtained high slope-efficiency of 62% in high power applications

By using quite uniformly nine-stacks side-around arranged compact pumping system, a high power Nd:YAG ceramic quasi-CW laser with high slope efficiency of 62% has been demonstrated. With 450 W quasi-CW stacked laser diode bars pumping at 808 nm, performance of the Nd: YAG ceramic laser with different output coupling mirrors has been investigated. Optimum output power of 236 W at 1064 nm was obtained and corresponding optical-to-optical conversion efficiency was as high as 52.5%. The laser system operated quite stably and no saturation phenomena have been observed, which means higher output laser power could be obtained if injecting higher pumping power. The still-evolving Nd: YAG ceramics are potential super excellent media for high power practical laser applications. (c) 2005 Optical Society of America.