自锁模掺钛蓝宝石激光超短脉冲脉宽小于31 fs

自锁模掺钛蓝宝石激光超短脉冲脉宽小于３１ｆｓ我们利用自己生长出的高质量、高掺杂的掺钛蓝宝石晶体，获得了高效率的超短脉冲激光输出。Ｔｉ３＋：Ａｌ２Ｏ３激光棒尺寸为４×４×５ｍｍ３，吸收系数α４９０＝６．２ｃｍ－１，品质因数ＦＯＭ＝１２０。采用自锁模技术...     

激光及其应用(连载2)

３激光在其他非生物领域中的作用３．１精密测量在长度测量中，１m长的测量误差仅为百分之几微米。用激光测量月球到地球的距离（３８４４０１km）误差只有１m（最好的误差记录为１０cm）。日本用于预防地震的长距离测距系统，全程８４km的测量误差竟能小于１mm。激光测速可测每秒零点几厘米到每秒几公里甚至更大的速度。１９７３年国际米尺定义咨询委员会推荐用He－Ne激光器测定的光速为２９９７９２．４５８km／s，有９位有效数字。３km的波导用激光准直，准确到０．５mm。用激光引导重２８０T的隧道掘进机在２．５km长的隧道内工作偏差…     

Cr~（4＋）：YAG可饱和吸收体被动调QNd：YAG激光脉宽小于9ns

Ｃｒ~（４＋）：ＹＡＧ可饱和吸收体被动调ＱＮｄ：ＹＡＧ激光脉宽小于９ｎｓＣｒ４＋：ＹＡＧ晶体既是新型的可调谐激光晶体，又是一种非线性可饱和吸收体，可用于１．０～１．２ｔｉｍ波段的被动调Ｑ和锁模，它具有结构简单、体积小、无驱动源从而无电磁噪声、热与光的?..     

面阵CCD图像传感器点破坏机理研究

用１．６μｍ脉冲激光聚焦辐照面阵ＣＣＤ图像传感器。遭破坏面积不到有效传感器面积的万分之一，整个ＣＣＤ图象传感器无图像输出。破坏阈值小于１２Ｊ／ｃｍ２。分析了破坏机理。     

氦氖激光单侧人迎穴照射对血压的影响

本试验观察了低功率氦氖激光单侧人迎穴位照射对人体血压的影响，实验结果健康组即血压正常者，照射前后血压值无变化，而高血压组，激光照射前后血压值差异非常显著（Ｐ＜０．００１），收缩压平均下降２．７３±２．１８ＫＰａ，舒张压下降１．６９±１．２９ＫＰａ．     

〔O2（^1Δg）〕2二聚物激光振荡研究

本文从理论上估算了〔Ｏ２（＾１Δｇ）〕２二聚物激光输出功率，在实验中以微波（２４５０ＭＨｚ）激励高纯氧产生〔Ｏ２（＾１Δｇ）〕２二聚物，采用平凹稳定谐振腔，在波长６５６．１ｎｍ处实现了〔Ｏ２（＾１Δｇ）〕２二聚物的激光振荡，当氧气压强为１３３．３Ｐａ，微波激励功率为６００Ｗ时，此结果在数量级上与理论上估算相同，另外还测得激光束散角约为３７．３ｍｒａｄ。     

连续CO_2激光对熔石英表面的增强处理研究

研究了连续ＣＯ２激光预辐照对熔石英表面增强的影响，通过ＣＯ２激光对熔石英表面均匀加热，用原子力显微镜和偏光显微镜观察了熔石英表面微观结构变化，发现熔石英表面形成压应力层，表面微裂纹和凹凸度减少。并用调Ｑ１．０６μｍ激光对熔石英表面损伤，其损伤阈值提高了１．５３倍。     

高光束质量钕玻璃板条振荡放大系统的实验研究

建立了磷酸盐钕玻璃板条一级振荡二级放大系统。将新型Ｃｒ４＋ＹＡＧ晶体用于激光介质为磷酸盐钕玻璃的振荡级中实现被动调Ｑ激光输出。经过两级放大后得到近衍射极限（Ｍ２ｘ＝Ｍ２ｙ＝１．５）的激光输出，能量放大率为１０．１     

两代激光新光束

根据较为完整的衍射原理，设计λ／２几何厚度的位相片并将其置于腔内尾镜上，在十瓦级封离型ＣＯ２激光器上实现了等效光束质量因子小于１的新光束。接着，在百瓦级，千瓦级快速轴流ＣＯ２激光器上实现了高光束质量激光束。这些可称之为第一代激光新光束。最后，提出降设计了一种带有突变反射率输出镜的激光谐振腔，在２０００Ｗ的横流ＣＯ２激光器上实现了１０００Ｗ准基模新光束。这可称之为第二代激光新光束。     

Cr,Tm,Ho：YAG晶体的光谱及其激光特性

本文报道１．０％Ｃｒ，６．０％Ｔｍ，０．４％Ｈｏ：ＹＡＧ晶体的吸收谱，荧光谱和该晶体的激光输出特性，用气压２×１０＾５Ｐａ的氙灯泵浦，频率１Ｈｚ，冷却水温１８￣２２℃，激光阈值为７３￣８４Ｊ，斜率效率为η＝２￣４％，单脉冲能量为１．４￣０．８Ｊ。     

Fourth harmonic generation in a resonant ring cavity

We have analyzed the generation of the fourth harmonic of pulsed laser radiation in a ring cavity that resonates at the second harmonic wavelength. With the help of numerical simulation, the dependence of the conversion efficiency on input laser power as well as cavity loss and nonlinear crystal coefficient is obtained. The model predicts over 50% conversion from the fundamental to the fourth harmonic with less than 1.2 MW of input power (10 mJ in 8.5 ns). The results compare well with experimental measurements where 39.5% infrared-ultraviolet conversion was obtained using low power from a Q-switched Nd:YAG laser     

大功率InGaAsP/InGaP/GaAs激光器特性研究

介绍了无铝激光器的优点 ;利用 LP-MOVPE生长了 In Ga As P/In Ga P/Ga As分别限制异质结构单量子阱 (SCH-SQW)结构 ,讨论了激光器的腔长对特征温度的影响。对于条宽 1 0 0 μm、腔长 1 mm腔面未镀膜的激光器 ,连续输出光功率为 1 .2 W,阈值电流密度为 41 0 A/cm2 ,外微分量子效率为 62 % ,并进行了可靠性实验。     

4.2W 连续波运转的LD泵浦Nd:YVO4/LBO 457nm蓝光激光器

报道了采用大功率光纤耦合模块端面泵浦Nd:YVO4晶体,LBO腔内倍频的高功率4.2 W连续波457 nm蓝光激光器.通过优化谐振腔设计和器件参数,使准三能级方式运转的914 nm激光得以高效率工作,并在此基础之上通过腔内倍频获得高功率的倍频蓝光输出.最终在泵浦功率为31 W时,蓝光输出功率达4.2 W,相应的光-光转换效率达13.5%,8 h连续工作激光输出功率的稳定性为1.2%.     

光栅掠入射脉冲染料激光器工作特性的研究

本文研究了无反馈腔结构的高损耗脉冲染料激光器和一般光栅掠入射结构的脉冲染料激光器的输出特性,分别获得了时间平均频带宽度为1.2GHz和2.5GHz的输出,本文还讨论了激光频带与腔参数的依赖关系,给定了光栅掠入射染料激光器的最佳工作条件。     

0.8 W optically pumped vertical external cavity surface emitting laser operating CW at 1550 nm

An InP based optically pumped vertical external cavity surface emitting laser has been designed and optimised for emission at 1550 nm. To overcome thermal limitations an intra-cavity synthetic diamond heatspreader is bonded to the gain structure. The laser produces 780 mW at -30/spl deg/C and 100 mW at 20/spl deg/C in a near Gaussian beam (M/sup 2/<1.2).     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

LD泵浦高效率折叠腔YAG／LBO蓝光激光器

介绍了一种 LD泵浦的高效率 Nd∶YAG/LBO蓝光激光器。采用 LBO代替 KN晶体进行腔内倍频 ;采用 V型谐振腔结构。实验证明 ,该设计具有倍频效率高、稳定性好、适合产品化等优点。在注入泵浦光功率为 1 .2 W时 ,获得 TEM0 0 模蓝激光输出达 63m W,偏振比超过1 2 0∶ 1 ,2 4 h功率不稳定度优于± 3%     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave （CW） 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd： YVO4 and using LBO as the intra-cavity SHG crystal. With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457 nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the output power is better than 1.2% for 8 h continuously working.     

Electrically pumped InGaAs quantum dot ring and cylindrical cavitylasers

Operation of an electrically pumped, cylindrical cavity laser containing a stack of five self-assembled InGaAs quantum dot layers is reported. A threshold current density of 47 A cm² is obtained at 150 K, with whispering gallery mode laser emission observed at ~1.2 eV. Fabrication of a ring cavity via the removal of part of the non-lasing central region of the cylinder results in a 30% reduction in threshold current     

Extremely narrow linewidth ( approximately 1 MHz) and high-power DFB lasers grown by MOVPE

A suitable structure of narrow linewidth DFB laser is studied experimentally. By thinning the active layer to around 0.07 mu m, controlling kappa L to 1.0, and improving the geometrical uniformity of active region, the linewidth less than 1 MHz is achieved at an output power of around 20 mW in 1.55 mu m DFB lasers with 1.2 mm long cavity length.<>