Experiment Study of LD Pumped Solid State of Dual-Frequency Laser

1 Introductionace--pumped SOlid-state laser (DPSL) have given rise to an attractive researchinterest and become one of the research focus in the field of laser due to theiradvantageS, such as high efficiency, compactness, steadiness, lOng lifetime and allsolldstate construction. The dual--frequency laser belongs tO the rather complex andadVanced techniqUe. It is applied widely in precise interferometry, laser ranger, laserradar, and heterodyne vibrometry.At present, there are lotS of pape…     

脉冲LD泵浦电光调Q深紫外激光器

研制了千赫兹213 nm深紫外全固态激光器。激光器采用脉冲LD侧面泵浦方式和电光调Q技术,实现了10瓦级基频光的稳定输出。利用多次倍频技术,实现了稳定的213 nm深紫外激光输出。当LD泵浦电流为80 A时,213 nm激光输出的最大平均功率达到了151 m W,激光器重复频率为1 k Hz,激光脉冲宽度为10ns,功率不稳定度为3%。同时,对激光在非线性晶体中的偏振匹配和不同重复频率条件下的激光器运转特性进行了分析。     

Experiment Research on a Highly Stable LD-pumped Solid State Laser

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｉｎｈｉｇｈｐｏｗｅｒｌａｓｅｒｓｙｓｔｅｍｈｉｇｈｌｙｓｔａｂｌｅｓｏｌｉｄｓｔａｔｅｌａｓｅｒｉｓｖｉｔａｌｌｙｉｍｐｏｒｔａｎｔ.Ｈｏｗｅｖｅｒ,ｄｕｅｔｏｔｈｅｔｅｍｐｅｒａｔｕｒｅｆｌｕｃｔｕａｔｉｏｎｉｎｔｈｅＬＤｐｕｍｐｓｏｕｒｃｅａｎｄｔｈｅｌｅｎｇｔｈｆｌｕｃｔｕａｔｉｏｎｏｆｌａｓｅｒｒｅｓｏｎａｎｔｃａｖｉｔｉｅｓＬＤ ｐｕｍｐｅｄｓｏｌｉｄｓｔａｔｅｌａｓｅｒｓｈａｖｅｐｏｗｅｒｉｎｓｔａｂｉｌｉｔｉｅｓｏｆａｒｏｕｎｄ± 10 % .Ｗｉｔｈａｍｏ…     

Experiment Research on a Highly Stable LD-pumped Solid State Laser

In high power laser systems, the stability of the seed laser is vitally important. This paper presents the work on the design and manufacture of a highly stable LD pumped solid state seed laser which has the advantages of being all solid state, compact, easy to manufacture and low cost. The laser was composed of two parts. One was an LD pumped 0.5 mm thin Nd: YLF laser system in which the instability was around±6% (3σ). The other was a close-looped laser power control system using external cavity power feedback. Using an electro-optic modulator, a 1×2 optical fiber splitter and a signal processing circuit, we successfully realized the highly stable LD pumped Nd: YLF laser in which the instability of laser output power was lower than±0.2 %/hour (3σ). A digital PID (Proportion, Integration and Differentiation) control method was used with a control frequency of 40 kHz. The 3 mW of highly stable laser power through the optical fiber was obtained.     

激光二极管抽运（Tm，Ho）：YLF微片激光器的实验研究

从理论上分析了准三能级(Tm，Ho)：YLF晶体的增益与温度关系，晶体温度的降低和长度的缩短有利于减小重吸收损耗对激光器运行性能的影响。在室温条件下，用2．7w波长为792nm激光二极管端面抽运Tm(原子数分数0．06)，Ho(原子数分数0．004．)：YLF微片激光器，阈值抽运功率为450W，当入射到晶体内的激光二极管功率为1．88W时，2μm激光最大输出功率为328mW，斜率效率为22．5％，光—光转换效率达17．4％。为达到激光最佳运行条件，还探讨了激光二极管波长，抽运光偏振方向以及晶体温度对Tm，Ho激光器性能的影响。     

Study on Square Wave Pulsewidth-variable Solid State Laser

Based on the rate equation of laser oscillation, we study the possibility of square wave output of a solid state laser in temporal domain. By means of the smooth cavity dumping, the reduction of output loss compensates the photon decrease in cavity. In experiment, we use two sets of avalanche transistor chains to control the functional voltage applied on the Pockels cell for getting uniform and pulsewidth-variable square wave laser pulse.     

Study on Square Wave Pulsewidth-variable Solid State Laser

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｍｏｄｅｒｎｓｃｉｅｎｔｉｆｉｃｔｅｃｈｎｏｌｏｇｙｐｕｔｆｏｒｗａｒｄｈｉｇｈｅｒａｎｄｈｉｇｈｅｒｒｅｑｕｉｒｅｍｅｎｔｓｆｏｒｔｈｅｓｔａｂｉｌｉｔｙｏｆｌａｓｅｒｗａｖｅｆｏｒｍ．Ｉｎ...     

自调Q激光器的理论分析

利用速率方程，对自调Q激光二极管抽运固体激光器进行了数值模拟。通过求解析解计算了自调Q脉冲的峰值功率、单脉冲能量、脉冲宽度、能量利用率、重复频率、平均输出功率等参量。根据自调Q二极管抽运固体激光器的特点，分别得到了使抽运阈值功率最小的最佳自调Q晶体长度和使光-光效率最大的最佳自调Q晶体长度。     

激光二极管端面泵浦的单频固体激光器的理论研究

给出了激光二极管端面泵浦的驻波激光器单频运转时的最大泵浦功率与腔参数和激光介质参烽之间的简单函数关系，对于单频激光器的设计具有实际指导意义。     

用于激光二极管抽运固体激光器热畸变补偿的微变形镜特性研究

在很多高功率的激光器中,由于热效应的缘故会导致激光器的光束质量大幅下降。为了改善激光光束的动态畸变,自适应光学是一种有效的方法。作为自适应光学系统的核心部件,设计了一种可用于大功率激光二极管抽运固体激光器(DPL)热畸变补偿的新型可变形反射镜,并且通过工艺流片实际制造出有效反射面积为30 mm×30 mm,拥有49个静电驱动单元的可变形反射镜。对该微机电系统(MEMS)微变形镜的变形特性进行了详细的理论分析和模拟研究,并和实际测量结果进行了比较,得到了满意的结果。为了实现闭环控制,对微变形反射镜的光学影响函数矩阵进行了全面测量,并用得到的电压矩阵对畸变激光光束的波前进行了校正。实验结果表明,微变形反射镜可以有效地改善激光光束质量。     

光泵NH3分子远红外激光研究

运用量子系统的密度矩阵理论，采用迭代法计算了光泵ＮＨ３分子远红外超辐射和腔式激光的频谱特性和相应的最佳工作气压。理论计算表明相对于超辐射方式，光泵腔式ＮＨ３分子远红外激光具有宽带辐射以及纵向调谐特性，且总的输出光强在一定条件下得到提高，最佳工作气压也较低。在实验上对ＴＥＡＣＯ２－１０Ｒ（８）和９Ｒ（１６）泵浦的Ｎ 红外超辐射和腔式激光器产生的远红外辐射进行了测量。结果表明理论计算与实验结果相符。     

军用脉冲激光测距技术与研究现状

简要介绍了军用脉冲激光测距机的工作原理和应用现状，分析了脉冲激光测距机中各种激光源的优缺点，并对现阶段军用脉冲激光测距机的研究热点和未来的发展趋势作了相应阐述。     

一种改进的激光二极管纵向泵浦固体激光器的腔模设计方法

以空间相关的速率方程理论为基础，提出了一种改进的激光二极管纵向泵浦固体激光器的设计方法，给出了在一定泵浦耦合方式下，激光腔模尺寸和输出耦合率最佳值的选取依据，以采用不同耦合系统的端面泵浦Ｎｄ：ＹＡＧ激光器设计实例，相应的实验结果与有理论计算符合得较好。     

高能固态激光阵列光束合成技术浅析

建立了高能固态激光阵列合成的模型,对相干合成型和非相干合成型的高能固态激光系统进行了分析和比较.引入光束传输因子(BPF)作为评价合成光束的光束质量,对湍流大气对板条激光器和光纤激光器相干合成与非相干合成远场光束质量的影响进行了定量分析.计算模型和结果为工程实际中合成方案的选择和评估提供了参考.     

激光二极管泵浦Nd：LMA激光器的连续波输出研究

报道有一个３Ｗ激光二极管端面泵浦Ｎｄ：ＬＭＡ激光器，实验采用三镜折迭像散补偿腔。在１０５４ｎｍ波长，激光器连续输出功率达６２０ｍＷ，斜率效率为５０％，光－光转换效率２０％，在１０８３ｎｍ波长处，激光器连续输出功率为６４ｍＷ，斜率效率为６％，光转换效率２．１％。     

激光二极管抽运(Tm,Ho)∶YLF激光器光谱特性实验分析

Ho∶YLF晶体的5I7和5I8斯塔克能级分裂数较多,形成2047~2070nm宽的增益谱带,对于可调谐2μm激光及宽带激光放大器研究具有重要意义。理论上分析了(Tm,Ho)∶YLF晶体的能级结构,并对晶体掺杂浓度和长度进行了优化。实验研究了激光二极管抽运微片Tm(原子数分数0.06),Ho(原子数分数0.004)∶YLF激光谱线可调谐特性,调谐范围2.0656~2.0671μm。利用(Tm,Ho)∶YLF晶体的宽增益谱特性,将其作为激光二极管抽运激光放大器,成功地将2.048μm(Tm,Ho)∶GdVO4激光功率放大了2.5倍。实验上测量了(Tm,Ho)∶YLF晶体在强抽运条件下480~492nm及530~550nm可见波段的上转换蓝绿光荧光谱。     

Thermal- and Spectral-Characteristics of High-Power Quasi-Continuous Wave 940-nm InGaAs Diode Laser Arrays

Experimental results of the thermal and spectral characteristics of a monolithic stack of high power quasicontinuous wave 940-nm InGaAs linear laser diode arrays have been evaluated. Thermal resistance as the most important thermal parameter characterizing a high-power laser diode package was obtained using the temperature rise measured directly by a thermo-camera. A new simple and convenient technique to measure a spectral transition of the emission from laser diode arrays is proposed. Spectral chirping due to the transient thermal power dissipated during the laser pulse was observed as a time-evolution of the spectral profile; it gave a comprehensible image of the chirping behavior. Comparing the temperature rise in the diode junction with the thermal simulation, it was determined that the thermal shift of central wavelength dλ/dT was 0.21 nm/°C. Detailed performances were identified for pumping a Yb³⁺ doped crystalline laser, and it was verified that the laser diode arrays were satisfactory to meet pumping source requirements for coupling to Yb³⁺ absorption linewidth.     

Experimental Study of Pulsed Optically Pumped Superradiant and Cavity NH3 Far-Infrared Laser

Using a grating tuned TEA-CO2 laser with 10R(8) and 9R(16) line to pumped superradiant NH3 far-infrared (FIR) laser which operated in the mode of amplified stimulated emission and Fabry-Perot cavity NH3 FIR laser with a sample tube of 100cm and 20cm in length respectively, the corresponding pulsed FIR lasers were obtained successfully. Meantime, the experimental measure method was improved. Besides, the operating performance and the spectral characteristics of superradiant and cavity NH3-OPFIRL were studied experimentally.     

激光二极管抽运Nd:YV04和频黄光激光器的理论及实验研究

为了达到最佳和频593 nm黄色激光输出,采用激光二极管(LD)端面抽运Nd:YVO4晶体,根据四能级系统的速率方程理论,建立了空间相关的两波长激光运转速率方程模型,由此导出两波光子数表达式.对LD端面抽运Nd:YVO4/KTP三镜复合腔结构的腔内和频黄光激光器,在满足参与和频的两基频光光子数密度相等的条件下,理论上得到了谐振腔的各个参数.实验比较了在满足两波光子数密度相等和两波振荡阈值相等两种情况下激光器输出的593 nm黄色激光功率.在抽运功率为12 W时,二种情况下分别得到了410 mW和340 mW的黄光输出,光一光转换效率分别为3.4%和2.8%.由此可见,在满足两波光子数密度相等的条件下可以得到更高转换效率的和频黄光输出.     

二维固体激光阵列逆达曼光栅相干合束技术模拟研究

采用逆达曼光栅将二维锁相相干的激光阵列进行相干合束并进行孔径装填是获得远场单一主瓣大功率高光束质量激光输出的一种有效技术方案,将其应用于大尺寸5×5固体激光相干阵列相干合束中,并进行了固体激光阵列合束孔径装填的理论分析和原理性验证实验,测量了系统的实际合束效率,同时进行了后焦面逆达曼光栅的加工和放置误差对合束效率影响的详细分析。实验结果表明,逆达曼光栅用于固体激光阵列相干合束是一种有效的技术方案,且可以通过调节光栅周期和傅里叶透镜焦距来适应系统对激光阵列占空比的要求。这对于开发基于逆达曼光栅相干合束的高功率高光质量的全固态激光系统具有重要的意义。