Performance and diagnostics of lasers initiated by the reaction of NO with ClO2

A purely chemical HCl laser employing transverse flow was operated with a maximum multiline output power of 13 W which represents a chemical efficiency of 8.6 percent based on the total exothermicity of the pumping reaction. The required nonequilibrium concentration of Cl atoms was generated by the branched chain reaction of NO with ClO2. Mass spectrometric and absorption spectroscopic measurements of species concentrations in the NO/ClO2reaction system showed that the effectiveness of production of the branched chain decreased with inereasing total pressure.     

Mechanistic framework for dry etching, beam assisted etching and tribochemical etching

A mechanistic framework is presented for impact assisted etch reactions. The consecutive reaction steps are assumed to be activated thermally and in parallel mechanically by fast particle impacts. The model explains the complicated temperature dependencies observed in dry etching and beam assisted etching, and it correlates the side wall profiles to the rate determining steps in the etch mechanisms. The framework is used to describe Reactive Ion Beam Etching (RIBE) experiments on InP with Ar⁺ ions and chlorine, in comparison with our recent Reactive Ion Etching (RIE) experiments of magnetic alloys in HCl plasmas. The framework is also applicable to other non-thermally activated etch reactions, as encountered in tribo-chemical etching and laser chemical etching.     

InAs/InP量子点激光器制备工艺研究

报道了通过化学湿刻蚀制备窄脊条InAs/InP量子点激光器的方法。激光器脊条主要是由半导体材料InGaAs和InP构成,通过选择合适配比的H2SO4∶H2O2∶H2O和H3PO4∶HCl腐蚀溶液和InP的腐蚀方向,在室温下选择性地腐蚀了InGaAs和InP,获得了窄脊条宽为6μm的量子点激光器。此激光器能够在室温连续波模式下工作,激射波长在光纤通信重要窗口1.55μm,单面最大输出功率超过12mW。     

XeCl准分子激光器钝化中的返潮现象

本文指出XeCl激光器钝化过程中激光器金属部件的氧化膜与HCl的反应是返潮现象的重要原因。分析了返潮现象对器件的危害及消除方法。     

近红外激光诱导InP（100）表面蚀刻反应

采用超声氯分子束和时间分辨质谱研究了由１０６４ｎｍ近红外激光诱导ＩｎＰ（１００）表面蚀刻反应的产物质量分，入射Ｃｌ＿２分子束的平动能效应，激光能量密度和表面温度的影响，并讨论了反应机理。     

CO激光激活化学反应分离铀同位素

由光声光谱方法测得的235UF6与238UF6的3ν3吸收光谱,选择出分离铀同位素的最佳CO激光谱线,对UF6与HCl的化学反应进行了激光催化化学反应实验,从而论证了CRISLA方法的可行性.     

化学反应热效应对激光熔凝区几何特征的影响

为了研究附加化学反应热的激光熔凝区特征,采用在低合金钢表面预制Mg,Al和Fe3O4涂层进行激光处理,得到了化学反应热影响激光熔凝区形貌的实验结果。结果表明,引入化学反应热源,使激光熔化区宽度、热影响区宽度和深度增加,熔化区的深宽比降低;Al和Fe3O4涂层的熔化深度比表面黑化处理的熔深深,Mg和Fe3O4涂层的熔化深度比表面黑化处理的熔深浅;利用多元合金氧化物还原化学反应热和激光形成复合热源,可以快速形成多元合金共渗的熔凝层。     

XeBr XeCl激光同时振荡的研究

本文报道了由ＨＣｌ／ＨＢｒ／Ｘｅ／Ｎｅ体系获得的ＸｅＢｒ与ＸｅＣｌ两种激光（２８２ｎｍ，３０８ｎｍ）同时振荡。对同时振荡的过程作了初步的分析，并在单独振荡的情况下研究了ＨＣｌ对ＸｅＢｒ激光能量及寿命的影响与ＨＢｒ对ＸｅＣｌ激光能量及寿命的影响。     

GaAs、GaP、InP、InGaAsP、AlGaAs、InAlGaAs的化学腐蚀研究

为研制全集成光开关、微片式激光器等，对ＧａＡｓ、ＧａＰ、ＩｎＧａＡｓＰ、ＩｎＡＩＧａＡｓ、ＡｌＧａＡｓ等材料的化学腐蚀进行了实验研究。为了研制ＩｎＡｌＧａＡｓ／ＩｎＡｌＡｓ／ＩｎＡｌＧａＡｓ微片式激光器，开发了Ｈ３ＰＯ４／Ｈ２Ｏ２／Ｈ２Ｏ薄层腐蚀液和ＨＣｌ／Ｈ２Ｏ选择性腐蚀液；为了研制ＩｎＧａＡｓＰ／ＩｎＰ／ＩｎＧａＡｓＰＴｂａｒ型光波导，开发了ＨＣｌ／Ｈ３ＰＯ４／Ｈ２Ｏ２薄层腐蚀液和ＨＣｌ／Ｈ２Ｏ２选择性腐蚀液；为了研制ＧａＰ、ＩｎＧａＰ光波导，开发了ＨＣｌ／ＨＮＯ３／Ｈ２Ｏ薄层腐蚀液。它们都具有稳定、重复性好、速率可控、腐蚀后表面形貌好等特点。除此之外，蚀刻成的ＧａＰ光波导侧壁平滑无波纹起伏。此种结果尚未见报导。     

HCl chemical lasing with HI and chloro compounds

HCL chemical laser action has been obtained from chloro compounds when HI was used as the source of H atoms. Laser action was produced on severalupsilon = 3-2, 2-1, and 1-0 HCl transitions when initiated by transverse pulsed discharges in HI-He mixtures containing such chloro compounds as CCl4, CHCl3, and several Freons. Both HCl and HF lasing were observed when a Freon (C2Cl2F4) containing F as well as Cl was used. The measured wavelengths for these HCl lasers correspond to excellent atmospheric windows for transmission of infrared radiation. No HCl lasing was obtained when HBr, H2S, or H2were substituted for HI.     

强化学激光器的研究与发展

化学激光器是以释能化学反应提供能源, 并且以化学反应产生粒子数反转为基础的。由于化学储能的巨大, 这类器件目前输出的连续波功率已达兆瓦级, 大大高于所有其他激光器;近年来, 由于流动介质均匀性的改善和采用选摸能呼高的光腔, 光束质量亦已达到近衍射极限。近年来的研究集中在发展短波长化学激光体系, 从较早的DF(～3.8 μm), HF(2.7 μm)到近期的O2-J体系(1.315 μm), 以及HF的泛频跃迁激光(～1.35 μm)。更进一步则希望发展可见光波段的化学激光器。这有可能通过电子激发志的受激辐射实现, 但是看来尚需较长时间的努力。     

激光与含能材料互作用的化学反应过程

反应性光声谱技术(RPAS)是近年来发展起来的一门新技术,它用于研究激光与物质互作用和快速的凝聚相化学反应。利用这一技术研究了激光与含能材料互作用的过程。研究发现并证实了脉冲激光激发下凝聚相的化学反应由光激发化学反应、慢速化学反应和快速加速的化学反应等三个阶段构成,反应性光声谱呈现出明显的双峰。     

固体化学反应的光声模型

建立了含固相化学反应的光声模型．通过对模型的数值模拟和对不锈钢、过氨酸铵复合材料样品的光声测试验证了该模型能较好地描述由激光引发的化学反应的光声效应。     

XeCl紫外激光与Xe红外激光同时振荡

Ｈｏ／Ｘｅ／Ｈｅ混合气体在横向快放电激发下同时输出ＸｅＣｌ紫外激光和Ｘｅ红外激光．研究了各参量对激光输出的影响，讨论了有关的动力学过程．     

激光诱导化学反应刻蚀石英玻璃的实验研究

针对目前常用的超短脉冲激光加工、激光诱导等离子加工、纳秒紫外激光加工石英玻璃刻蚀率低下的问题,提出一种能够大范围、高刻蚀率、低裂损刻蚀石英玻璃的新方法,即利用1064nm红外激光诱导Ba(OH)2化学反应刻蚀。本文主要从不同能量密度激光诱导化学反应刻蚀机理进行分析,实验表明,当激光能量密度超过16 J/cm2时,石英玻璃被刻蚀;当激光能量密度在16~24 J/cm2之间时,仅物理作用去蚀石英玻璃,故刻蚀率随激光能量变化较小;当激光能量密度在24~42 J/cm2之间时,刻蚀率随激光能量密度变化较大,该阶段Ba(OH)2以及其分解生成的BaO在高温条件下都与石英玻璃主要成分SiO2发生化学反应并生成BaSiO3,故刻蚀率较高;激光能量密度在42~46 J/cm2时,化学反应速率趋于饱和,故该阶段刻蚀率随激光能量密度变化较小。     

An electrically pulsed HCl laser

A pulsed electrical discharge in a flowing mixture of Cl2and HI produces laser action on the 3 → 2 and 2 → 1 vibrational transitions of HCl.     

BT20钛合金的激光表面重熔

激光表面重熔对提高钛合金表面的耐蚀性具有显著的效果.采用脉冲Nd-YAG激光器对BT20钛合金进行了重熔.表面显微结构、硬度分布和在3wt% NaCl与1M HCl溶液中的耐蚀性进行了研究.激光重熔处理后耐蚀性得到显著的提高.耐蚀性的提高归因于快速凝固造成的组织变化.     

Diving–Surfacing Smart Locomotion Driven by a CO2‐Forming Reaction,with Applications to Minigenerators

Harvesting energy from environment has attracted increasing attention for its potential applications in fabricating minigenerator. However, most studies in the fabrication of mini‐ or nanogenerators are based on the concept of piezoelectricity or triboelectrification while few of the reports paid attention to the classical theory of Faraday's law. Herein, a pH responsive smart surface is combined with the reaction between CaCO₃ and HCl to develop a new minigenerator, which can convert mechanical energy generated from the chemical reaction into electrical energy through cutting magnetic lines with moving conductive lines. The conductive lines are connected with a smart device consisting of a pH‐responsive cube, a hydrophobic cube, and a quartz cell window; the device can perform diving‐surfacing cycled motions with an intelligent initiation through the adjustment of the solution. The device can surface through gathering CO₂ bubbles from the reaction between CaCO₃ and HCl and dive by releasing the bubbles on the water/air interface. Moreover, the results demonstrate that the inert CO₂ was nonhazardous to the smart surfaces, which is meaningful for durable electricity generation.     

Theoretical simulation of electron-beam-excited xenon-chloride (XeCl) lasers

By developing a comprehensive computer code fore-beam excited XeCl lasers, we studied mainly the effect of Ar and Ne diluents on the performance characteristics of XeCl lasers. According to the analysis of the XeCl* formation process, the XeCl* relaxation process, and the 308 nm absorption process, it is found that the XeCl* formation efficiency is determined mainly by the rate of the charge transfer process (from Ar+ and Ne+ diluent ions to Xe+); in other words, by the difference between ionic potentials of Xe and the diluent gas used. The extraction efficiency is found to be decided mainly by the quenching rate of a three-body reaction for a short-pulse (55 ns) and a high-excitation-rate (∼ 3 MW/cm³) pumping, and by the absorption process for a long-pulse (500 ns) and a low-excitation-rate (∼ 0.2 MW/cm³) pumping. However, note that no appreciable difference in the intrinsic efficiency is found between the Ar/Xe/HCl and Ne/Xe/HCl mixtures. We also analyzed the dependence of the intrinsic XeCl laser efficiency on the pumping pulse width and excitation rate for Ar/Xe/HCl and Ne/Xe/HCl mixtures. As a result, the same intrinsic efficiencies are obtainable for both Ar- and Ne-based mixtures although the optimum operating conditions are slightly different. The maximum intrinsic efficiency of 5 percent is obtainable both for the Ar/Xe/HCl mixture at 3 atm and with 1.5 MW/cm³, 200 ns (FWHM) pumping and for the Ne/Xe/HCl mixture at 4 atm and with 2 MW/cm³, 200 ns (FWHM) pumping.     

All-optical high speed demultiplexing with a semiconductor laser amplifier in a loop mirror configuration

A novel, purely optical technique for demultiplexing high speed time-division multiplexed data is demonstrated. The technique uses the SLALOM (semiconductor laser amplifier in a loop mirror) The data rate is not limited by the gain recovery time of the semiconductor laser amplifier. The same technique can also be used for multiplexing.<>