Preliminary results of intraoperative mitomycin-C in the treatment and prevention of glottic and subglottic stenosis

Mitomycin-C is an antineoplastic antibiotic that acts as an alkylating agent by inhibiting DNA and protein synthesis. It can inhibit cell division, protein synthesis, and fibroblast proliferation. The purpose of this pilot study is to investigate intraoperative applications of topical mitomycin-C in treatment and prevention of glottic and subglottic stenosis. Eight patients with posterior glottic and/or subglottic stenosis were treated with endoscopic CO2 laser excision followed by topical application of 0.5 cc of 0.4 mg mitomycin-C per milliliter of saline for 4 minutes at the surgical site. After mean follow-up of 15 months (10-20) all patients had clinical improvement of their airway and resolution of their preoperative symptoms. No complications were noted in this study. Although a longer follow-up and further controlled studies are needed, the use of topical mitomycin-C may prove useful in the treatment and prevention of subsequent restenosis and scar formation in the larynx and trachea.     

"解剖"激光告警

介绍了激光告警的作用,分析了激光告警器的原理、性能要求和分类,然后分别阐述了典型的光谱识别型、相干识别型和散射探测型激光告警器,并对不同类型的激光告警器进行了比较评价.     

二极管双侧抽运横流连续液体激光系统性能模拟

为解决无机液体激光系统的热效应问题,采用激光二极管双侧抽运横向流动的Nd3 :POCl3:ZrCl4溶液以很好地减小热效应,实现液体激光系统高功率高光束质量输出。建立了液体激光理论模型,分析了工作参量对系统能量转换效率与介质热效应的影响;模拟了系统在不同吸收系数和不同流速下的能量转换效率,远场光斑分布以及激光束亮度分布。模拟结果表明:采用二极管作为抽运源可以获得很高的能量转换效率,而且光束质量较好;在给定抽运体积和抽运强度为800 W/cm2时,介质的吸收系数位于2.5~3.0 cm-1,流速约为25 m/s时,输出功率与光束质量实现最佳匹配,激光束亮度最高,系统性能达到最佳。     

流动激光非稳定振荡器,放大器基本特性比较分析

根据流动激光腔中流动的非平衡混合气体各能态布居数和强辐射相互作用达到稳定振荡的过程和相应的三维分布状态的数值模拟计算结果,发展了相应的振荡器和放大器基本特性的简化计算公式.其计算结果与多种器件、多种腔体的实测结果相符.具体比较分析了流动激光振荡器与放大器的基本特性,得到一些基本原则,为相应器件的优化设计提供理论依据.     

Design and performance of a transverse discharge, UV-preionized mercury-bromide laser

The design, construction, and operating characteristics of a pulsed, transverse discharge-pumped HgBr laser, capable of operation at pulse repetition frequencies as high as 100 Hz, are presented. Having an active length of 53 cm, this laser system is preionized by two sets of spark arrays and average single pulse energies of 55 mJ are produced from Ne/N₂/HgBr₂ (natural abundance) vapor mixtures, with an output coupling of 50% and 17 J of energy stored in the pulse forming network. Based on measurements of the laser pulse energy for several values of cavity output coupling, the small signal gain coefficient and saturation intensity for the laser were determined to be 4.7% cm^–1 and 260 kW cm^–2, respectively. The single pass gain-to-loss ratio is 12.4.     

激光技术的40年

介绍第一台激光器的诞生,综述激光技术４０年来的应用情况及其影响以及激光及激光技术在中国的发展简况。     

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.     

激光调制和激光通信原理的演示

给出了一种演示激光调制和激光通信原理的电路设计。     

Direct Generation of Tunable UV Picosecond Laser Pulses Using Spectrotemporal Selection

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医用激光仪器的发展和质量控制

介绍了我国近年来医用激光仪器的发展概况、产品抽检情况及其质量分析。给出了如何提高医用激光仪器质量的几点建议     

激光微加工技术在集成电路制造中的应用

激光微加工技术以非接触加工方式,高效率、无污染、高精度、热影响区小的优点在微电子集成电路制造中得到了广泛应用.介绍了在集成电路制造封装中采用的激光微调、激光打孔、激光清洗、激光柔性布线和激光微焊技术.     

激光无铅钎焊速度的影响因素(英文)

为了提高激光无铅钎焊的速度,对影响激光无铅钎焊速度的因素(如激光的参数、所用钎料和基体的特性、钎焊的系统结构等)进行了分析研究。研究认为,在激光器、钎料及基体等已定的情况下,相对于那些受到机械惯性制约的移动激光加工头或移动工作台的激光钎焊系统,一种配备了振镜扫描系统和f-theta聚焦透镜的激光钎焊系统具有更高的钎焊速度。另外,对激光钎焊过程中激光束的扫描路径进行了优化,这种优化能在不增加硬件成本的基础上大大缩短总扫描路程,较大程度地提高激光钎焊速度。最后通过实例对激光钎焊的快速性进行了验证。     

远红外可调谐喇曼激光器理论

本文用缀饰原子方法解出四能级系统远红外激光增益系数的解析表达式。结果表明,远红外增益谱一般由四个共振峰组成,取合适的失谐量,可能得到两个正的增益极大,并分别对应于喇曼增益和线中心增益。     

美国战术激光武器转型的思考

概述了战术激光武器的原理、特点以及类别,着重介绍了美国战术激光武器的发展过程、现状;并对美国未来战术激光武器的发展和关键技术做出了分析探讨。     

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。     

双频激光技术研究新进展及发展趋势

双频激光器在干涉测量和光学传感等技术领域扮演极其重要的角色。综述了近年来双频激光技术研究的新进展(包括双折射双频He Ne激光器、双折射双频Nd:YAG激光器和双纵模半导体激光器),简要介绍了各种双频激光器的工作原理,分析了这些双频激光器在频差大小、频差稳定性和频差调谐特性等方面的优缺点,指出了今后双频激光技术研究的发展趋势。     

Influence of various gases on the emission of laser generated plume

We report the experimental results on the investigation of the emission charac teristics of the XeCl laser generated plume from the Copper target in variant gas ambient. The dependence of the emission intensities on the gas pressure are strikingly different among these gases. This behavior is attributed to the difference in ionization of the employed gases.     

舰载激光武器的发展历程及趋势分析

舰载激光武器作为常规舰载武器的有益补充,已经受到世界各国的普遍关注。本文介绍了舰载激光武器的发展历程,系统阐述了舰载激光武器系统的组成及功能,并分析了它们的主要技术特点及关键技术。最后,论述了舰载激光武器的发展动向,指出自由电子激光器和光纤激光器是未来舰载激光武器的发展重点,而低能、小体积重量的激光器也会逐步用于舰载激光武器,未来舰载激光武器会向小型化、高效率方向发展。     

高能激光六十年:回顾与展望

激光的本质是微观粒子的有序运动,而热是微观粒子的无序运动,高能激光产生过程中这一对矛盾贯穿始终,可以说高能激光的发展史,就是一部与废热的斗争史。回顾高能激光发展的六十年,剖析高能激光的科学内涵,我们大致将其划分为前后三十年的两个阶段,前一阶段着重解决能用的问题,后一阶段重在解决好用的问题。围绕产热、散热,我们剖析了激光功率、光束质量、效率三者之间的内在关联,简要回顾了各类高能激光器的发展历程,评价了各类高能激光的特色,展望了高能激光未来的发展路径。