Dye Laser-pumped Cr: LiSrAIF_6 Laser

ＤｙｅＬａｓｅｒ－ｐｕｍｐｅｄＣｒ：ＬｉＳｒＡＩＦ_６Ｌａｓｅｒ￥ＷＵＸｉｎｇ（Ｄｅｐｔ．ｏｆＰｒｅｃｉｓｉｏｎＩｎｓｔｒｕｍｅｎｔＥｎｇｉｎｅｅｒｉｎｇ，Ｔｉａｎｊｉｎ３０００７２，Ｃｈｉｎａ）Ｔ．Ｏｋａｄａ，Ｋ．Ｋａｅｄａ（Ｄｅｐｔ．ｏｆＥｌｅｃ?..     

Experimental study on miniature pulsed CH3OH far-infrared laser

Using a grating tuned TEA-CO₂ laser with 9P(16) line to pump a 10cm or 20cm long miniature Fabry-Perot cavity CH₃OH laser, pulsed far infrared(FIR) lines of 570.6um and 918um wavelengths were observed, the latter is a new line. Operation performance and spectral characteristics of the miniature CH₃OH laser were studied. The project was supported by the Special Research Foundation of Doctorate Station in University of P.R.C.     

一种掺钕光纤激光器与倍频技术实现的数值模拟

从双包层光纤激光器的速率方程和光传输方程出发，建立数学模型，进行数值计算并对掺钕光纤激光器输出功率沿光纤的分布以及不同光纤长度下抽运功率和输出功率沿光纤的分布进行了数值模拟。以808nm半导体激光器为抽运源，掺钕双包层光纤为增益介质，并以KTP作为倍频晶体，计算并模拟其倍频效率和相位匹配角。最后，对光纤激光器及其倍频的实现进行了模拟研究。结果表明，该光纤激光器能够高效率地实现可见光输出。     

CO-laser photoacoustic detection of phosgene (COCl2)

Detection of COCl₂, a highly toxic gas in chemical industry, using laser photoacoustic spectroscopy is presented. The spectrophone system used has a broad band LN₂ cooled CW CO laser as a source of radiation, which operates from 4.8–8.4 um in the mid-infrared. Using an extracavity open longitudinal resonant cell, absorption signals to about 30 CO laser lines in the 5.45 um region could be observed. detection sensitivity has been estimated to be ppb order.This work has been supported by the NSFC     

O_2（~1△_g）二聚物的兰色激光振荡

通过微波（２．４５０ＧＨｚ）激励高纯氧产生Ｏ２（１△ｇ）二聚物，利用放大自发辐射法首次测得了Ｏ２（１△ｇ）二聚物在４８６ｎｍ处的小信号增益系数。采用平凹稳定谐振腔观察到了４８６ｎｍ的兰色激光振荡，最大激光输出功率为１３０μＷ，发散角为２８ｍｒａｄ。     

Dual Wavelengh Pr:YLF Laser

ＤｕａｌＷａｖｅｌｅｎｇｈＰｒ：ＹＬＦＬａｓｅｒ￥ＲＵＡＮＳｈｕａｎｇｃｈｅｎ（Ｘｉ＇ａｎＩｎｓｔｉｔｕｔｅｏｆＯｐｔｉｃｓａｎｄＦｉｎｅＭｅｃｈａｎｉｃｓ，ＡｃａｄｅｍｉａＳｉｎｉｃａ，ＸＩ＇ａｎ７１００６８，Ｃｈｉｎａ）Ｊ．Ｍ．Ｓｕｔｈｅｒｌａｎ...     

Study on Laser Conditioning of Optical Coatings

ＳｔｕｄｙｏｎＬａｓｅｒＣｏｎｄｉｔｉｏｎｉｎｇｏｆＯｐｔｉｃａｌＣｏａｔｉｎｇｓ￥ＺＨＡＯＱｉａｎｇ；ＦＡＮＺｈｅｎｇｘｉｕ；ＷＡＮＧＺｈｉｊｉａｎｇ（ＳｈａｎｇｈａｉＩｎｓｔｉｔｕｔｅｏｆＯｐｔｉｃｓａｎｄＦｉｎｅＭｅｃｈａｎｉｃｓ，Ｃｈｉｎｅｓ...     

V型槽衬底内条形大光腔可见光半导体激光器

采用一种新的液相外延工艺，研制出具有大光腔结构的Ｖ型槽衬底内条形可见光发射半导体激光器，其光谱波长为７７９－７８４ｎｍ，室温连续工作阈值电流为６０ｍＡ，具有２倍阈值的基模工作时，线性输出光功率可达８ｍＷ，４ｍＷ下工作寿命已超过３０００小时。     

KrF Laser-induced Damage to ZrO_2/SiO_2 Coatings

ＫｒＦＬａｓｅｒ－ｉｎｄｕｃｅｄＤａｍａｇｅｔｏＺｒＯ_２／ＳｉＯ_２Ｃｏａｔｉｎｇｓ￥ＷＡＮＧＮａｉｙａｎ；ＧＡＯＨｕａｉｌｉｎ（ＣｈｉｎａＩｎｓｔｉｔｕｔｅｏｆＡｔｏｍｉｃＥｎｅｒｇｙ，Ｐ．Ｏ．Ｂｏｘ２７５－７，Ｂｅｊｉｊｎｇ１０２４１３，Ｃｈｉｎ...     

基于大基模体积的10mJ飞秒钛宝石激光再生放大器

文章报导了基于大基模体积的高能量飞秒钛宝石激光再生放大器的设计与实验研究,在重复频率10 Hz、抽运能量60 mJ的激励下,得到了单脉冲能量17.4 mJ的种子脉冲放大结果,压缩后的脉冲宽度为40.6 fs,能量为13.9 mJ.借助于此大基模体积再生腔,仅增加一级多通放大,实现了峰值功率达1.9 TW飞秒激光脉冲输出.结果表明,大模体积再生放大不仅降低了后续放大对抽运能量的要求,也可以单独压缩实现再生腔直接输出10 mJ量级的飞秒激光脉冲,是大能量高峰值功率飞秒激光系统的优质前端.     

Wideband CO laser in problems of laser sensing of minor gaseous components in the atmosphere

In the present work it is demonstrated that a wideband CO laser operating at fundamental and overtone vibrational transitions is a promising source of laser radiation for remote laser sensing of the atmosphere. A compact slab RF-discharge CO laser has been designed. The optimal operating conditions are determined for this CO laser. In experiments, the maximum average output laser power was ∼12 W for lasing efficiency of ∼14%. Under fixed experimental conditions, stable lasing (with fluctuations of the output laser characteristics ≤5%) was observed during more than one hour, which suggests that we first excited the sealed-off mode of cryogenic slab RF-discharge CO laser. The frequency-selective mode was first obtained for this laser. Wavelengths for sensing of nitrous oxide, nitrogen dioxide, methane, formaldehyde, and some other gases on near-ground propagation paths are determined. Our experiments and calculations confirm that this CO laser is promising for laser gas analysis. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 76–83, November, 2008.     

Widely Tunable Middle Infrared Optical Parametric Oscillator Pumped by the Q-Switched Ho:GdVO_4 Laser

We demonstrate a middle infrared ZnGeP_2 optical parametric oscillator pumped by the Q-switched Ho:GdVO_4 laser. When the incident Ho pump power is 4.12 W, the maximum average output power of the ZGP-OPO laser is 2.05 W, corresponding to a slope efficiency of 74.6%. The ZGP-OPO laser produces 4.2 ns mid-infrared pulses at a pulse repetition rate of 5 kHz. In addition, we obtain 0.8 um of tunable range for the signal wave and 2.1 um of tunable range for the idler wave.     

种子注入的短脉冲激光器特性研究

 从LD泵浦固体激光器优化设计原则出发，设计了一种微型二极管泵浦激光器，并对种子激光器的结构和参数进行了优化。该激光器运转稳定，输出光束质量高，光束发散角小，光-光转化效率为17-4%，斜率效率可达24%，输出功率可达80mW。将此种子激光注入到调Q激光器中，改善了调Q激光器的输出特性，使得激光脉冲的建立时间缩短了40ns，输出的横模场分布得到了明显改善。     

1.55μm InGaAsP/InP应变量子阱激光器的LP－MOCVD生长

本文首次报导了生长温度为550℃,以三甲基镓(TMGa)和三甲基铟(TMIn)为Ⅲ族源,用低压金属有机物气相沉积(LFMOCVD〕技术,高质量1.62um和1.3umInGaAsP及In_0.57Ga_0.43As_0.98P_0.04/In_0.73Ga_0.27As_0.6P_0.4量子阶结构的生长,并给出了1.55umGaAsP/InP分别限制应变量子阱结构激光器的生长条件,激光器于室温下脉冲激射,其阈值电流密度为2.4kA/cm².     

液体泡沫对激光的伪装性能分析

为了研究液体泡沫的激光伪装应用,实验分析了液体泡沫对1.06 m激光的伪装性能。采用对比试验方法测得了不同液体泡沫结构参数下的1.06 m激光回波衰减值,结果显示,衰减值最高可达66%,最低为36%。结合激光伪装要求,以草地和钢板为例,理论计算分析了液体泡沫用来实现1.06 m激光伪装可行性。结果表明,使用2 cm厚液体泡沫对钢板进行伪装,激光回波衰减达到36%,在草地背景伪装要求的30%~40%范围内。说明液体泡沫具有较好的1.06 m激光伪装性能,利用液体泡沫可实现激光伪装和地面目标有效防护。     

Emission Spectrochemical Analysis of Metals Using a Nitrogen Laser

Comparative studies of the possibilities of using pulsed nitrogen and Nd:YAG lasers for emission spectrochemical analysis of copper-zinc alloys have been made. The nitrogen laser developed on the basis of the commercial excimer laser provided an energy of radiation pulses of 5 mJ with an error of less than 0.8% at a repetition frequency of 100 Hz. The high stability and the high pulse repetition frequency of the nitrogen laser were attained due to the additional high-speed fan inside the laser chamber, which provided agitation and circulation of the gas mixture. It has been shown by experiment that the spectral emission of the plasma formed by means of the nitrogen laser is characterized by intensity fluctuations with a root-mean-square deviation of 1.4%, whereas in the case of using an Nd:YAG laser it was 14.3%. The advantages of the nitrogen laser that are due to the increased signal-to-background ratio and the suppression of the selective evaporation effect have been revealed.     

四硼酸铝钕晶体及其小型全固态激光器

当前,全固态激光器在向万瓦级大功率方向发展的同时,也在向微型化发展。利用碟片全固态激光器可获得千瓦级以上激光,利用微片全固态激光器则可实现小体积、高密度、中小功率激光输出。获得高功率高密度激光的关键在于激光材料。本文从碟片和微片激光器的发展和对激光基质材料的要求出发,概述自激活激光晶体的研究,特别对四硼酸铝钕[NdAl3(BO3)4,简称NAB]晶体的结构、生长、性质及其作为有应用前景的小型片状激光器的候选材料作了详细的介绍。近期,采用面积为4×4 mm2,厚度为0.39 mm的微片NAB晶体,用885 nm半导体激光器为光源泵浦,获得了4.6 W的1.063 μm激光的有效输出,其斜效率达到64%,充分显示了NAB晶体作为自激活激光晶体在微片激光器中的应用前景。     

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。     

射频超导腔加速性能的改进

为提高超导加速腔的加速梯度和Q值，改进了薄膜型超导腔的加速性能。研究证明，对于铜铌溅射腔，在无氧铜衬底和铌膜之间加入NbN 层可以提高铌膜的超导转变温度，改善晶格结构；对纯铌超导腔提出了改进方法，在传统的纯铌超导腔表面制备多层的超导-绝缘-超导复合膜可以屏蔽Nb腔表面的界面场，提高超导腔的临界磁场，从而提高了铌腔的加速梯度。     

Determination of the Refractive Index of Dielectrics by Means of Light‐Induced Diffraction Gratings

Consideration is given to the possibilities of measuring the refractive index n of dielectric samples by means of spontaneous gratings produced by an spolarized laser beam in a photosensitive thin film applied to a sample in vacuum. With the specific choice of the film thickness, the value of n is determined from diffraction measurements of the period of a spontaneous grating with the error n = ±0.002. The method allows measurement of n isotropic and anisotropic samples within the range 1.32.5 on plane and cylindrical surfaces with the area determined by the section of the laser beam that induces the spontaneous grating. Examples of measurements of n on plane surfaces of glasses, a LiNbO₃ crystal, and on the cylindrical surface of a ruby rod are presented.